Muscle & Workout Supplements Review (Creatine and
Branched-chain Amino Acids)
Find the Best Muscle
Enhancement Supplements. See Which BCAA and Creatine Supplements Passed CL's
Tests & the Top Picks.
Medically reviewed and
edited by Tod Cooperman, M.D. 
Last Updated
: 06/19/2021 | Initially Posted:
06/23/2017
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Table of Contents
Summary
·
What Does It Do? Creatine is an amino acid that helps
supply muscles, including the heart, with energy, particularly for short-term,
maximal exercise (See What It Is). Some, but not all studies suggest
creatine supplements can improve muscle strength and endurance during
repeated high-intensity exercise of short duration, such as weight lifting and
sprinting, but is not helpful in purely aerobic exercise. Creatine may also be
useful in improving exercise tolerance in patients with congestive
heart failure (CHF) and muscle strength in people with muscular
dystrophies (See What It Does).
·
Is It Safe? Creatine is generally considered safe when taken in
appropriate amounts for short periods of time, but little is known about
potential long-term adverse effects of creatine. There is some concern that
long-term use at high doses (20 grams/day) may adversely affect the kidneys and
cardiovascular system (See Concerns and Cautions).
·
How to Take? Commonly, a "loading" dose of creatine is taken
for 5 to 14 days, followed by a maintenance dose. However, some studies have
shown a benefit using a constant dose rather than a larger loading dose. If
using a powder or mix, drink it as soon as possible -- creatine will begin to
break down once in liquid. Also, when using creatine supplements, it is
important to drink about 8 cups of water per day. For dosage details, see ConsumerTips™).
·
Which Is Best? Creatine comes in various forms, the
most common being the monohydrate form, which also yields the greatest amount
of free, usable creatine. Certain formulations are inherently unstable and
should be avoided. ConsumerLab.com's tests for this
Review showed that one creatine product exceeded CL's limit for impurities.
Among the others, CL's Top Pick provided 5 grams of
pure creatine monohydrate powder for less than 10 cents. (See What CL Found and CL's Top Picks)
BCAAs
·
What Do They Do? Branched chain amino acids are the
essential amino acids isoleucine, leucine and valine that the body cannot
produce (see What It Is). Taking BCAAs before and after
exercise may help reduce or delay the onset of muscle soreness and improve
muscle recovery. Leucine appears to be the most significant BCAA for
stimulating protein synthesis (see What It Does).
·
Are They Safe? BCAAs are considered safe at standard
doses, but may interact with certain medications (See Concerns and Cautions).
·
How to Take? For muscle recovery and to prevent soreness, daily doses
of 1 to 5 grams have been used. How to take this and doses for other uses are
explained in ConsumerTips™.
·
Which Is Best? ConsumerLab's
tests revealed that one product contained less leucine than claimed. Among
products which passed CL's tests, several provided 5 grams of BCAAs for about
30 cents. See CL's Top Picks.)
Other Muscle Enhancers
Learn about glutamine, HMB, and taurine. Also see information about the
muscle enhancing effects of vitamin D, protein powders, and "nitric oxide" supplements.
What It Is:
Creatine is a nitrogen-containing amino acid that is naturally
produced in the human body from other amino acids, primarily in the kidneys and
liver. Most (95%) of your body's creatine is found in muscle tissue, though it
is also found in the heart, brain and other tissues. Creatine helps supply
muscles with energy, particularly for short-term, maximal exercise. Food
sources of creatine include meat, poultry, and fish.
Branched-chain amino acids (BCAAs) are a group of three essential
amino acids isoleucine, leucine and valine that the body cannot produce and
needs to get from dietary sources. They are called "branched-chain"
because their structure has a "branch" off the main trunk of the
molecule. They take part in several metabolic processes in the body, are
precursors in the synthesis of alanine and glutamine, and make up approximately
one-third of skeletal muscle. During aerobic exercise of long duration (such as
long-distance running, cycling, or swimming), the body may break down muscle in
order to release BCAAs to be used as energy. Supplementing with BCAAs during or
after a workout is believed to prevent muscle breakdown. Dietary sources of
BCAAs include dairy protein, eggs, meat, chicken, fish and legumes.
What It Does:
Creatine: According to some studies, creatine can improve muscle
strength and endurance during repeated high-intensity exercise of
short duration, such as weight lifting and sprinting. It is not of benefit in
purely aerobic exercises (e.g., distance running, cycling, swimming).
A study among resistance-trained men found that the addition
of creatine to a two-month workout regimen resulted in significantly greater
increases in muscle size, particularly upper body muscle, than placebo. Muscle
size increased by 7.1% with creatine vs. 1.6% with placebo in the upper body,
3.2% vs 0.7% in the trunk, and 2.1% vs. 0.7% in the lower body. The men
performed resistance exercises four days per week (two days of upper and two
days of lower body exercise) and took a "loading dose" of creatine
(about 5.5 grams four times daily) for the first week of exercise, followed by
a maintenance dose (2.2 grams per day) for seven weeks (Nunes, Nutr Health 2017).
Creatine supplementation appears to be more effective in people with low
initial creatine levels, while people with higher levels may not respond as
well. Since there are no vegetable sources of creatine, vegetarians are often
low in creatine and respond well to creatine supplementation (Burke, Med Sci Sports Exerc
2003). It may also be more effective in muscles that have not been
trained or have atrophied. One study indicated that healthy young subjects
undergoing rehabilitation therapy after cast removal recovered faster when
taking creatine (Hespel, J Physiol 2001).
Some, but not all, studies have shown benefits in older adults when
creatine is combined with resistance training. For example, a well-designed
three-month study in people over the age of 65 suggested that creatine (5
grams/day) could help increase total body mass, lean body mass and muscle
strength when combined with resistance training (three times per week) (Brose, J Gerontol A Biol Sci
Med Sci 2003). A study of older men (average
age 58) who participated in resistance training two days per week and took
either creatine or placebo daily for two months found that both groups
experienced similar increases in upper body strength but those who took
creatine had greater increases in leg press strength (54% vs. 35%) and total
lower body strength (43% vs. 30%). (The lack of a benefit in upper body
strength may have been due to the fact that the training program included more
lower-body exercises.) The men consumed 0.1 grams of creatine monohydrate per
kg of bodyweight per day (an average daily dose of 9.5 grams) mixed with water
and consumed within five minutes after exercise and once daily on non-training
days (Bernat, Appl Physiol Nutr Metab 2019).
The creatine used in the study was Creapure (AlzChem Trostberg GmbH), which is
found in products such as Nutricost Creapure Creatine Monohydrate and AthleticXtreme German Creatine.
On the other hand, a study among 35 older men (average age
57) found that taking a similar amount of creatine monohydrate as in the study
above but in two divided doses per day for 12 months along with resistance
exercises did not improve muscle strength compared to placebo,
although both groups showed similar, significant improvements in lower body
strength (62% and 72% in the creatine and placebo group, respectively) and
upper body strength (11% and 24% in the creatine and placebo group,
respectively) (Candow, Nutr Health 2020).
In a small study among older adults (average age 58)
who did not perform resistance exercise, short-term
supplementation (10 days) with daily doses of creatine ranging from 8 grams to
25 grams did not improve muscle strength and endurance, or
measures of functionality (i.e. balance, walking, etc.) compared to placebo (Chami, J Nutr Health Aging 2018).
A clinical study among people with fibromyalgia found that
taking creatine daily for 16 weeks increased upper- and lower-body muscle
strength by up to about 10% compared to placebo, but did not improve other
symptoms of fibromyalgia such as pain, sleep quality, or overall quality of
life. A "loading dose" of 5 grams four times daily for 5 days
followed by 5 grams once daily was used (Alves, Arthritis Care Res, 2013).
Creatine may also be useful in improving exercise tolerance in patients
with congestive heart failure (CHF), treating gyrate
atrophy of the choroid and retina, increasing exercise capacity in
patients with McArdle disease, improving muscle strength in people
with muscular dystrophies, and improving lean body mass and quality
of life in patients with chronic obstructive pulmonary disease (COPD)
(Fuld 2005).
Creatine has not been found to be helpful in slowing the
rate of Parkinson disease progression, based on a multi-year
study of nearly one thousand men and women. The patients, who were also
receiving dopaminergic drugs, received 10 grams of creatine monohydrate daily
or placebo. The study was terminated early after interim results showed no
benefit with creatine compared with placebo after at least 5 years of therapy.
There were also no detectable differences in adverse events (NET-PD, JAMA 2015).
Branched-chain amino acids (BCAAs): BCAAs are necessary for making
protein and stimulating muscle production throughout the body. The
research on the benefits of BCAAs for muscle enhancement is mixed —
some human research indicates that BCAAs help reduce muscle breakdown during
exercise although other research has found that BCAAs have no
performance-enhancing effects. BCAAs may reduce loss of muscle during long
periods of muscle disuse in some settings.
BCAA supplementation before and after exercise may help reduce or delay
the onset of muscle soreness, improve muscle recovery, and improve immune
function after long distance intense exercise (Negro 2008; Shimomura
2006). It appears that free BCAAs circulating in the blood prevent protein
breakdown, and that leucine in particular plays the most significant role in
stimulating protein synthesis (Kimball 2006). For this reason, a ratio of 2:1:1
(leucine: isoleucine: valine) is often recommended.
A study of women and men (ages 60 to 80) found that taking
BCAAs, along with other essential amino acids (EAAs), for one week before total
knee replacement and for two weeks after surgery reduced postoperative
muscle loss (particularly in the quadriceps and hamstring muscles) and
accelerated the return of functional mobility, as compared to placebo (Dreyer, J Clin Inves 2013).
The benefits were also seen when reassessed six weeks after surgery. Twenty
grams of EAAs were taken twice daily between meals. If physical therapy or
resistance exercise took place after surgery, the EAAs were taken afterwards,
as this has been found to better stimulate muscle development than when taken
before exercise. Each twenty gram serving consisted of
the BCAAs leucine (3.6 grams), valine (2.4 grams), and isoleucine (2.0 grams),
along with the other EAAs lysine (3.2 grams), phenylalanine (3.2 grams),
threonine (2.8 grams), histidine (2.2 grams), and methionine (0.6 grams). When the same researchers repeated the study with a somewhat
larger group of patients for a longer duration of supplementation (for six
weeks after surgery), those who supplemented with EAAs had reduced muscle loss
in the quadriceps (-8.5% supplemented vs. -13.4% unsupplemented)
and the hamstring (-7.4% vs. -12.2%) of the affected leg compared to placebo,
although there were no differences in functional mobility or muscle strength
between the two groups (Dreyer, JB JS Open Access 2018). The authors
noted that since the last study, the hospitals involved implemented new
post-operative recovery protocols (such as walking and exercising sooner after
surgery) that may explain why functional mobility and strength were similar in
both groups.
A small but well-controlled study in 19 active, middle aged
individuals (ages of 45 to 60) in Texas found that, during 14-days of forced
continuous bed rest, supplementing meals with leucine helped
partially protect muscle mass and function. Subjects consumed approximately 4
grams of leucine (calculated as 27 mg per pound -- or 60 mg per kg -- of body
weight) as powder mixed with juice or milk with each of three regular meals per
day. After the 14 days, in comparison to those in a control group given the
amino acid alanine instead of leucine, the leucine group better maintained knee
function (-7% vs. -15%) and endurance (-2% vs. -14%). Leucine also protected
against loss of lean body mass during the first week (-1.8 lb
vs. -3.3 lb), but not enough to be statistically
significant over 14 days (-2.2 lb vs. -3.3 lb). While the control group experienced a modest but
statistically significant increase in body fat (averaging 2 lb),
the leucine group gained only 1.1 lb (English, Am J Clin Nutr 2016).
[Note: Many products in the Review below provide substantial amounts of leucine
— see the second column in the Results table.
Contrary to the above studies, a study of 16 healthy young
men found that loss of lean mass and muscle strength from 7-day immobilization
of one leg using a knee brace was not reduced with leucine compared to
a placebo. The men consumed 5 grams of leucine or a placebo three times daily
with meals during immobilization (Edwards, Am J Clin Nutr 2020). It is unclear if these results
differed from the earlier studies because of the age of the participants, the
form of disuse (i.e., bedrest vs. single leg immobilization), or other factors.
One small study in Iran among 30 sedentary postmenopausal
women (average age 56) with possible age-related muscle loss showed
that participating in resistance training three days per week and taking 9
grams of BCAAs (providing 4.5 grams of leucine, 2.25 grams of isoleucine, and
2.25 grams of valine) on each day of resistance training, with half the dose
taken 30 minutes before exercising and the other half taken 30 minutes later,
did not improve muscle strength or affect regulatory factors in the blood that
influence muscle growth compared to placebo after 8 weeks. However, both groups
showed improvements compared to baseline (Bagheri, Exp Gerontol 2021).
Preliminary evidence suggests that BCAAs may be useful in conditions including
anorexia, mania, cirrhosis of the liver, tardive dyskinesia, and may improve
appetite in people with cancer. Other amino acids, such as arginine and
carnitine, are commonly found in sports-related supplements, but there is no
evidence of clear benefit for such supplementation in sports.
See ConsumerTips™ for
information buying and using these supplements.
Other Muscle Enhancing Supplements:
While creatine and BCAAs tend to be the most popular muscle enhancing
supplements in the market and are the focus of this review, other ingredients
commonly used or included in products designed to increase strength and
endurance are:
Glutamine: is the most abundant free amino
acid found in your blood and is involved in cellular energy production and many
other biological functions. Glutamine plays a role in maintaining muscle
cells, the immune system and the digestive tract.
Although glutamine does not seem to improve exercise
performance, glutamine levels in the body may decrease after prolonged exercise
and there is some preliminary evidence that glutamine supplementation may
reduce the incidence of infection in athletes who are over-training (Castell, Eur J Appl Physiol Occup Physiol 1996; Walsh, Sports Med 1998). Supplementation with glutamine may also reduce blood
markers of muscle damage (such as creatine kinase, myoglobin and aspartate
transaminase) after strenuous exercise compared to placebo, as was shown in a
study among professional athletes who took 6 grams of glutamine daily (as
capsules taken every morning) for 20 days (Cordova-Martinez, Nutrients 2021).
A number of clinical studies have evaluated glutamine as a treatment for
intestinal disorders. For example, glutamine may enhance intestinal absorption
in people with AIDS wasting (particularly when taken with HMB and arginine).
Glutamine also seems to help reduce oral mucositis (painful mouth irritation)
caused by cancer chemotherapy in some, but not all, people.
Glutamine has been promoted as protecting the gastrointestinal tract from
damage (e.g., increased permeability, bleeding, etc.) which can be caused
by non-steroidal anti-inflammatory drugs (NSAIDs). A small study
found that taking multiple doses of glutamine around the time of intake of
NSAID dosing partly prevented the increase in permeability, but it did not work
when taken only before (i.e., 1 week prior or even 30 minutes prior) NSAID
dosing. To be effective, doses of glutamine (dissolved in water) were taken at
several times: seven grams 30 minutes before, one gram with,
and two more one-gram doses after the NSAID (75 mg of
indomethacin) (Hond,
Aliment Pharmacol Ther 1999). However, there are no published
clinical studies investigating the effects of glutamine supplementation on
stomach pain, ulceration or bleeding risks associated with NSAID use.
Glutamine may also be helpful for people with diarrhea-predominant
irritable bowel syndrome (IBS-D). In a study among 106 men and women
(average age 31) with postinfectious IBS-D, 79.6% of those who took glutamine
for two months had a clinically significant improvement in the severity of
symptoms (> 50 points or more on a symptom scale from 0 — 500) compared to
just 5.8% of those who took a placebo (whey protein). Areas of greatest
improvement with glutamine supplementation were abdominal pain, quality of
life, and satisfaction with bowel habits, compared to placebo. In those who
took glutamine, bowel movement frequency decreased by 2.5 bowel movements per
day versus no change in the placebo group. Intestinal permeability (as measured
by a 24-hour urine test) was restored to normal with glutamine but not with
placebo. In the study, 5 grams of glutamine powder mixed with 8 oz. of water
was taken three times daily (Zhou, Gut 2018).
Like creatine, high protein foods such as meat, fish, beans and dairy products
are excellent dietary sources of glutamine.
HMB (hydroxy methylbutyrate)
is produced by the body when muscle tissue breaks down, such as during
training. Small amounts are found in citrus fruits and catfish. It is
hypothesized that HMB supplements may signal the body to slow the breakdown of
muscle tissue. However, the evidence for HMB as an athletic muscle enhancer is
contradictory. Some studies indicate that HMB may enhance strength and muscle
mass in response to weight training and may help prevent muscle damage during
prolonged exercise. Other research suggests that HMB may have greater effect
when used with creatine. Yet further studies have found HMB to have no muscle
enhancing benefits. Other studies indicate that HMB may help prevent wasting in
people with AIDS -- particularly in combination with amino acids such as
arginine and glutamine (Clark, JPEN J Parenter
Enteral Nutr 2000).
Taurine is one of the most abundant compounds
in the body, and is one which your body can make out of vitamin B-6 and the
amino acids methionine and cysteine. Taurine is found in the nervous system and
muscle, including heart muscle. and appears to help regulate heartbeat,
maintain cell membranes, and affect the release of neurotransmitters in the
brain.
One small, controlled study found that 2 grams of taurine plus 3.2 grams of
BCAAs daily for 2 weeks prior to and 3 days after high-intensity exercise
reduced delayed-onset muscle soreness and muscle damage compared to placebo
although neither supplement alone helped (Ra, J Int Soc Sports Nutr 2013).
Taurine supplementation has also been shown to reduce muscle cramps in people
with cirrhosis (liver damage and may be helpful in people with acute viral
hepatitis and congestive heart failure). (See the Taurine Supplements Review for
more information).
Quality Concerns and
Tests Performed:
When
creatine is metabolized in the body, it creates a waste product called
"creatinine," which is normally removed from the body by the
kidneys. (Blood levels of creatinine are commonly used to evaluate
kidney functioning). Creatinine also appears in unstable creatine
supplements as a result of improper manufacturing or breakdown of the creatine,
as does another manufacturing by-product, dicyandiamide. To pass testing,
ConsumerLab.com required that the total of creatinine and
dicyandiamide represent no more than 0.1% of the amount of creatine in a
product.
Creatine is converted to creatinine in water under acidic conditions
(Ganguly 2003). Previous testing conducted by
Consumerlab.com has shown problems with creatine sold in some liquid forms, in
which creatine appears to have broken down into creatinine. Although
creatinine and dicyandiamide in small amounts do not appear to pose
a safety risk, they provide no benefit to your body and must be eliminated
through the kidneys. Hence, manufacturers like to claim their products are
"100% pure," "99% pure," or "dicyandiamide free"
because high quality creatine should not contain these impurities. Purity has
become an issue because creatine dosages are relatively large -- often as much
as 20 grams/day (about 4 rounded teaspoons of creatine powder) during
"loading" or initial supplementation.
Neither the U.S. Food and Drug Administration (FDA), nor any other federal or
state agency, routinely tests muscle enhancing products, nor any supplement,
for quality prior to sale. As part of its mission to independently evaluate
products that affect health, wellness, and nutrition, ConsumerLab.com purchased
a variety of creatine and BCAA products to determine whether they possessed the
quality and amount of these ingredients stated on their labels. Creatine
products were also tested to determine whether they were contaminated with
creatinine or dicyandiamide. Any non-chewable tablet or caplet
product was also tested for its ability to properly disintegrate ("break
apart") and any product containing whole botanical ingredients or large
amounts of minerals were tested for heavy metals (lead, cadmium, and arsenic).
(See How Products Were Evaluated for
information on testing methods and passing score).
What CL Found and Top
Picks:
Creatine:
Among the creatine supplements that ConsumerLab.com selected for testing, one
product, MuscleTech Creactor, failed to meet CL's quality criteria and is
listed as "Not Approved" in the results table below. This product
contained its listed amount of creatine; however, it was found to contain 2.4
mg of creatinine and 0.01 mg of dicyandiamide per 2-gram scoop,
(equal to 0.18% of the amount of creatine in the product, exceeding ConsumerLab.com's limit of 0.1% of creatinine and
dicyandiamide in the total amount of creatine.) This was confirmed in a second
independent laboratory. Although in small amounts these compounds do not appear
to pose a safety risk, they provide no benefit to your body and must be
eliminated through the kidneys. High quality creatine should not contain these
impurities (see Quality Concerns).
Top Pick for Creatine:
Four of the creatine products which CL selected for testing met CL's quality
criteria and are listed as "Approved" in the Results Table below. Two
additional products (each indicated with a CL flask) are included in the table
for having passed the same testing through ConsumerLab.com's
voluntary Quality Certification Program, having been
tested at the request of their manufacturers/distributors. Also listed is one
product similar to one that passed testing but which is sold under a different
brand name.
Among products Approved for their quality by CL, the cost to obtain an
equivalent amount of creatine found in 5 grams of creatine monohydrate ranged
from just 9 cents to $2.50. CL's Top Pick among these
is BulkSupplements.com Creatine Monohydrate, which provides 5
grams of creatine monohydrate per 1 teaspoon of powder for 9 cents (the lowest
in cost among creatine products). Creatine monohydrate is the most common form
of creatine in supplements, and, yields the largest amount of free, usable creatine
compared to other forms (See ConsumerTips™).
If you prefer the convenience of a pill, the lowest cost, Approved, product
was Universal Creatine Chews — Grape Flavor, providing 5 grams of
creatine monohydrate in four chewable tablets for 36 cents.
Note: ConsumerLab did not test any
liquid creatine products because creatine is inherently unstable in
liquid and when CL tested three different creatine liquids in 2014 each was
found to provide much less creatine than expected or was contaminated with
higher than acceptable amounts of creatinine. The amounts of creatine in
two products were far less than has been found to beneficial.
BCAAs:
Among the BCAA supplements that ConsumerLab.com selected for testing, one
product, BulkSupplements.com BCAA 2:1:1, failed to meet CL's
quality criteria and is listed as "Not Approved" in the results table
below. This product contained just 80.6% of its listed amount of leucine, and
this was confirmed in a second independent laboratory.
Top Pick for BCAAs:
Four of the BCAA products which CL selected for testing met CL's quality
criteria and are listed as "Approved" in the Results Table below. One
other product which was selected by ConsumerLab, BPI
Sports Best BCAA, was neither "Approved" nor "Not
Approved" as it did not claim an amount of BCAAs on the label (the amount
of BCAAs CL found in this product is listed in the table
(below). Three additional products (each indicated with a CL flask) are
included in the table for having passed the same testing through ConsumerLab.com's voluntary Quality Certification Program,
having been tested at the request of their manufacturers/distributors.
Among products Approved by CL for their quality and labeling, the cost to
obtain 5 grams of BCAAs ranged from just 26 cents to $2.34. CL's Top
Pick among these products is also the lowest in cost: Ultimate
Nutrition BCAA 12,000. It provides 6 mg of BCAAs in one 6-gram scoop of
powder for 26 cents. If you prefer a pill, several brands passed our quality
tests, but, be aware that you will have to take a large number of pills to get
the same amount of BCAAs, as well as pay more, e.g., eight softgels
of MET-Rx BCAA 2200 (4.4 grams of BCAAs for 50 cents) or ten
capsules of Optimum Nutrition Mega-Size BCAA (5 grams for 97
cents).
All of the products contained a greater amount of leucine than isoleucine or
valine (typically in a 2:1:1 ratio), which may be beneficial due a greater role
of leucine in protein synthesis, as noted earlier.
Test Results by Product:
Below are two results tables. Within each
table, products are listed alphabetically. The first table lists test results
for seven creatine supplements. ConsumerLab.com selected five of these
products. Two other products (each indicated with a CL flask) were tested at
the request of their manufacturers/distributors through CL's voluntary Quality Certification Program and
are included for having passed testing. Also listed is one product similar to
one that passed testing but is sold under a different brand name.
The second table lists test results for nine BCAA supplements. ConsumerLab.com
selected six of these products. Three other products (each indicated with a CL
flask) were tested at the request of their manufacturers/distributors through
CL's voluntary Quality Certification Program and
are included for having passed testing.
Shown for each product is the labeled amount and form of creatine or BCAAs, the
serving size recommended on the label, and the unit (e.g., pill, teaspoon or
scoop) size. Products listed as "Approved" met their label claim and ConsumerLab.com's quality criteria (see Passing Score). Those that did not are listed
as "Not Approved" with an explanation of the problem found. The full
list of ingredients is available for each product by clicking on the word
"Ingredients" in the first column. A cost comparison is provided in
the last column.
The second column of the results table includes descriptions of the pill size
and type of pill (tablet, chewable tablet or softgel),
or notes if the product is in powder form. Products that were in pill form were
relatively long ranged in length from about 3/4 of an inch to over one inch in
length. These are fairly large sizes compared to pills of other types of
supplements. The tested pills are grouped by length as follows:
Softgel Sizes by Length: (Oblong shape unless noted
otherwise)
- Very large: over 25.4 mm (> 1 inch)
- Large: up to 25.4 mm (1 inch)
- Medium/Large: up to 19 mm (3/4 inch)
- Medium: up to 12.7 mm (1/2 inch)
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RESULTS OF CONSUMERLAB.COM TESTING OF MUSCLE & WORKOUT
SUPPLEMENTS |
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Product Name, Serving
Size, and Suggested Daily Number of Serving on Label |
Claimed Amount and
Form of Creatine Per Labeled Daily Serving |
--TEST RESULTS-- |
Cost For Daily
Suggested Serving On Label |
||
|
OVERALL RESULTS: |
Contained Expected
Amount of Creatine |
Did Not Exceed
Contamination Limit for Creatinine and Dicyandiamide |
|||
|
|
2,500 mg to 5,000 mg |
APPROVED |
|
|
$0.05-$0.09 |
|
|
5,000 mg to 10,000 mg |
APPROVED |
|
|
$0.14-$0.28 |
|
|
750 mg4 |
APPROVED |
|
|
$0.334 |
|
|
750 mg |
NOT |
|
Found 2.4 mg creatinine and 0.01 mg
dicyandiamide per serving (0.18% of creatine found)5 |
$0.35 |
|
|
5,000 mg to 20,000 mg |
APPROVED |
|
|
$0.10-$0.39 |
|
|
5,000 mg |
APPROVED |
|
|
$1.04 |
|
|
5,000 mg |
APPROVED |
|
|
$0.36 |
|
Myology™ Creatine Extreme
Caps 1000 mg (5 capsules, once daily) |
Similar to Precision Engineered Creatine
Extreme Caps 1000 mg. |
$0.67 |
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Unless otherwise noted,
information about the products listed above is based on the samples purchased
by ConsumerLab.com (CL) for this Product Review. Manufacturers may change
ingredients and label information at any time, so be sure to check labels
carefully when evaluating the products you use or
buy. If a product's ingredients differ from what is listed above, it may not
necessarily be of the same quality as what was tested. |
|||||
|
Copyright ConsumerLab.com, LLC,
2017. All rights reserved. Not to be reproduced, excerpted, or cited in any
fashion without the express written permission of ConsumerLab.com LLC. |
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|
RESULTS OF CONSUMERLAB.COM TESTING OF MUSCLE
& WORKOUT SUPPLEMENTS |
||||
|
Product Name, Serving Size, and Suggested
Daily Number of Serving on Label |
Claimed Amount and Form of Branched-Chain
Amino Acids (BCAAs) Per Labeled Daily Serving |
--TEST RESULTS-- |
Cost For Daily Suggested Serving On Label |
|
|
OVERALL RESULTS: |
Contained Expected Amount of Branched-Chain
Amino Acids (BCAAs) |
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|
Powders: |
||||
|
|
Unclaimed amount of
amino acids |
NA2 |
Found 2,132 mg total BCAAs (1,023 mg leucine,
521 mg isoleucine and 588 mg valine) per daily serving |
$1.00 |
|
|
4,284 mg |
NOT |
Found only 645 mg Leucine (80.6% of listed
amount) per serving |
$0.27 |
|
|
5,000 mg |
APPROVED |
|
$0.30-$0.91 |
|
|
5,000 mg to 15,000 mg |
APPROVED |
|
$0.60-$1.80 |
|
|
4,000 mg |
APPROVED |
|
$1.50 |
|
|
6,000 mg to 36,000 mg |
APPROVED |
|
$0.31-$1.88 |
|
Pills/Tablets: |
||||
|
|
2,200 mg to 4,400 mg |
APPROVED |
|
$0.25-$0.50 |
|
|
1,000 mg4 |
APPROVED |
|
$0.194 |
|
|
1,200 mg to 2,400 mg |
APPROVED |
|
$0.45-$0.90 |
|
|
||||
|
Unless otherwise noted, information about the products
listed above is based on the samples purchased by ConsumerLab.com (CL) for
this Product Review. Manufacturers may change ingredients and label
information at any time, so be sure to check labels carefully when evaluating
the products you use or buy. If a product's
ingredients differ from what is listed above, it may not necessarily be of
the same quality as what was tested. |
||||
|
Copyright ConsumerLab.com, LLC, 2017. All rights reserved.
Not to be reproduced, excerpted, or cited in any fashion without the express
written permission of ConsumerLab.com LLC. |
||||
ConsumerTips™:
Creatine: Ideally,
product labels should indicate the amount of creatine per serving and the
dosage form (for example, powder, drink mix, liquid, capsules, or tablets).
Because creatine is well absorbed, there is little advantage to purchasing a
liquid form (it's also not stable in water) over a drink mix or a capsule or
tablet. When comparing costs, consider the amount of creatine provided in the
product. The labeled amount of creatine monohydrate in powdered products
generally ranges from 100 to 500 grams (1 gram = 1,000 mg) per container while
the labeled amount in liquid products may be as little as 5 to 60 grams per
bottle. Be aware that different forms of creatine yield different amounts of
free, usable creatine. For example, creatine monohydrate (the most common form
in supplements) is 88% creatine, while creatine ethyl ester is 86%, creatine
HCl is 79%, dicreatine malate and tricreatine
malate are about 70%, creatine ester phosphate is 62%, and creatine AKG is
47.5%. So you actually get more creatine when, for
example, you take 10 grams of creatine monohydrate as opposed to 10 grams of
these other forms. (Note: Unlike labels on vitamin and mineral supplements,
which must disclose amounts of usable nutrient per serving (i.e., amounts of
calcium rather than calcium carbonate), labels on creatine supplements
typically do not show amounts of usable creatine but of the whole
compound.) Another form of creatine is creatine nitrate. A clinical trial
(partially funded by the manufacturer) showed that 3 grams of creatine nitrate
raised blood levels of creatine 33.5% more than 3 grams of creatine
monohydrate, and a combination of 3 grams of creatine nitrate with 3 grams of
creatinine (a breakdown product of creatine) raised creatine levels
even more — by 50%. Creatine levels in muscle also improved more with the two
nitrate preparations than with monohydrate after 5 days of supplementation.
However, drawbacks to creatine nitrate and its combination with creatinine are
an unpleasant odor and a possible negative effect on kidney function (Ostojic, Food Sci Nutr 2019; Joy J Int Soc Sports Nutr 2014).
A branded creatine called KreAlkalyn is marketed as a
buffered creatine" although the form of creatine in this ingredient is
unclear. Apparently KreAlkalyn had been promoted at
one point to be up to ten times more powerful" than ordinary creatine, but
a small study (commissioned by a manufacturer of creatine monohydrate) showed
it was no better than creatine monohydrate in promoting changes in muscle
creatine content, body composition, strength, or anaerobic capacity (Jagim, J Int Soc Sports Nutr 2012).
Be mindful of terms like "complex" or "proprietary blend"
as they often do not disclose the actual amount of creatine (or other
ingredients) promised in the product. Instead, look for products that clearly
list the amount(s) of each form of creatine. Also be sure to check the
suggested serving sizes -- they can be very different across products, ranging,
for example, from less than 250 milligrams to over 20 grams (20,000 mg). Find a
product that will provide the dose you want at the lowest cost.
Dosing regimens are designed to increase the levels of creatine in muscle
tissue. The standard practice is to start with a "loading" dose of 15
to 20 grams of creatine per day for 5 to 14 days, followed by a maintenance
dose of 2 to 5 grams of creatine per day. On this dosing regimen, the maximum
creatine storage should occur within 2 to 4 weeks. However, some studies have
shown benefit using a constant dose (such as 5 grams daily) rather than a
larger loading dose (Brose 2003).
Some believe that creatine levels in muscle build up more rapidly when taken
along with carbohydrates; hence, some creatine products also contain
carbohydrates. Other studies report that creatine uptake is dependent upon
sodium rather than carbohydrates, suggesting that it may not be necessary to
include sugars or carbohydrates with supplementation (Ganguly
2003). Also, when taking creatine, it is important to drink about 8 cups (64
ounces) of water per day. Finally, if you use a powder or mix, it is advisable
to drink it as soon as possible (within 10 minutes of mixing) since the
creatine can begin to break down once in liquid.
Since it's possible that creatine's potential to improve muscle strength and
endurance may be due, in part, to its ability to increase water retention in
muscles cells (Franco, Rev Bras Med Esporte 2007; Ziegenfuss, J Exerc Physiol Online 1998),
concern has been raised that caffeine — another popular exercise performance
enhancer, may interfere with these effects because caffeine is a known diuretic
(i.e., it can increase water lost through urination). A review of 20 clinical
studies investigating the effects of taking caffeine and creatine together
reported that short-term caffeine supplementation, such as a
single dose of caffeine taken one hour prior to exercise, does not interfere
with, and in some cases, improves, exercise performance; however, chronic caffeine
supplementation may blunt the effects of creatine use -- possibly by affecting
muscle relaxation time or by causing gastrointestinal discomfort (Trexler, Int J Sport Nutr Exerc Metab 2015). The
review noted that while there did not appear to be significant health concerns
when taking caffeine and creatine together within recommended doses, "it
may be prudent to avoid chronic, high-dose caffeine intake to maximize the
ergogenic effect of creatine supplementation."
For other diseases, the following amounts have been used:
·
COPD: 15 grams per day for 14 days followed by 5 grams for 10
weeks
·
Gyrate atrophy: 1.5 grams per day
·
Fibromyalgia: 20 grams per day for 5 days followed by 5 grams
daily
·
Heart failure: 20 grams per day for 5 to 10 days
·
McArdle disease: 150 mg/kg daily for 5 days followed by 60 mg/kg
per day
·
Muscular dystrophies: 10 grams per day for adults or 5 grams per
day for children
Branched-chain amino acids (BCAAs): For muscle recovery and to
prevent soreness daily doses of 1 to 5 grams have been used. For other
conditions, the following amounts have been used:
·
Anorexia: 12 grams daily
·
Cirrhosis of the liver: 12 grams daily
·
Improving appetite in people with cancer: 4.8 grams daily
·
Mania: 60 grams daily for 7 days
·
Tardive dyskinesia: 666 mg/kg daily for 3 weeks
·
Recovery from knee replacement surgery: 20 grams of EAAs
(including 8 grams of BCAAs) twice daily 1 week before surgery and 2 weeks
after
·
Reducing loss of muscle mass and function during extended bed
rest: Approximately 4 grams of leucine with each meal
BCAA formulas designed
for muscle recovery typically provide two milligrams of leucine for every
milligram of isoleucine and valine.
Other muscle enhancing ingredients:
Glutamine: To reduce infections related to
over-training 5 grams taken at the end of exercise has been used. For
AIDS-related wasting, 40 grams per day is suggested or 14 grams if used with
HMB and arginine. For oral mucositis, 4 grams of glutamine suspension swished
in the mouth then swallowed every four hours around the clock starting with the
first dose of chemotherapy and continued until chemotherapy ends or the mouth
irritation resolves has been used (Peterson, Cancer 2006).
Drinking 10 grams of glutamine dissolved in water three times daily may also
help to reduce oral mucositis (painful mouth irritation) and/or dermatitis in
some, but not all people with head and neck cancer undergoing chemoradiotherapy
(Tsujimoto, Oncol Rep
2015; Lopez-Vaquero, Mol Clin Oncol 2017).
HMB: The term "HMB" generally refers to the calcium salt
of HMB (calcium beta-hydroxy beta-methylbutyrate
monohydrate), so that the labeled weight includes about 14% calcium. For muscle
building and increasing strength, 3 grams daily is used, divided into two or
three doses. For AIDS-related wasting 3 grams daily is typically used
"along with 14 grams each of glutamine and arginine, administered in two
divided doses.
Taurine: To help treat congestive heart failure, 2 grams of taurine
3 times daily has been used. In acute viral hepatitis, 12 grams of taurine
daily has been used. To reduce muscle soreness after intense exercise, 2 grams
of taurine plus 3.2 grams of BCAAs daily for 2 weeks prior to and 3 days have
been used (Ra, J Int Soc Sports Nutr 2013).
Concerns and Cautions:
There have been many instances in which muscle-enhancement
supplements have been found to contain ingredients not properly disclosed on
the label, such as steroids and stimulants (see ConsumerLab.com's Recalls and Warnings Section).
These adulterants may possibly explain an increased risk of testicular cancer
among men who have reported using muscle-building supplements. Compared to men
who never used these supplements, the risk of testicular cancer was found to be
65% higher among those who had, 121% higher if used before age 25, 156% higher
if used for more 36 months or longer, and 177% higher if two or more of these
supplements had been used (Li, Brit J of Cancer 2015).
Creatine is generally considered safe
when taken in appropriate amounts, but it may cause weight gain due to water
retention. Despite anecdotal reports, creatine generally does not seem to cause
muscle cramping, diarrhea, or dehydration (Persky, Creatine and Creatine Kinase in Health and Disease 2007; Kreider, J Int. Soc Sports Nutr
2017).
Although a few case studies reported high creatinine levels (a
creatine-related compound measured in urine samples to assess kidney function)
in people taking creatine, clinical studies among healthy, young adults have
generally not shown creatine (up to 10 grams daily for up to 5
years) to significantly increase creatinine levels (Poortmans, Med Sci
Sports Exerc 1999; Pline, Ann Pharmacother 2005; Persky, Creatine and Creatine Kinase in Health and Disease 2007).
Even high doses of creatine taken long-term (up to 30 grams daily for up to 5
years) have not been associated with an increased risk of kidney dysfunction in
healthy adults.
Many experts consider the risk of kidney injury due to creatine supplementation
to be low even among people with pre-existing kidney dysfunction (Kreider, J Int. Soc Sports Nutr
2017). However, the safety of creatine in people with kidney
dysfunction has been validated in only short-term studies, so the long-term
safety remains unclear. To be safe, people with kidney disorders should consult
with their physician before using creatine.
Creatine kinase (CK) activity (also known as creatine phosphokinase (CPK)
activity), generally increases after exercise and indicates muscle injury, but
several clinical studies have shown that taking creatine does not affect
CK activity (Persky, Creatine and Creatine Kinase in Health and Disease 2007; Machado, Braz J Pharm Sci 2009).
There is some concern that creatine should not be used with ephedra and caffeine,
but this is based on a single report of ischemic stroke in an athlete who was
taking this combination (Vahedi, J Neurol Neurosurg Psychiatr 2000).
(See "ConsumerTips™"
for more about caffeine and creatine.) There is also concern that creatine
might cause heart arrhythmias based on a report of atrial fibrillation associated
with creatine use in an otherwise healthy 30-year-old man (Kammer,
Pharmacotherapy 2005).
There is concern that creatine supplementation
may cause hair loss because a placebo-controlled study in college-age males
showed that creatine increased levels of dihydrotestosterone (DHT), an androgen
that can cause hair follicles to become smaller, leading to male pattern
baldness. In that study, participants were given 25 grams of creatine daily for
one week followed by 5 grams daily for another two weeks, and DHT levels rose
56% after the first week, with levels remaining elevated by 40% at the end of
three weeks (van der Merwe, Clin J Sport Med 2009).
However, in the study, the creatine group started with DHT levels that were
23% lower than the placebo group and actually only increased
to a level still within the normal range for DHT. Furthermore, this increase in
DHT with creatine supplementation has not been replicated in other clinical
research, and no clinical study evaluating creatine has reported hair loss or
balding as a side effect (Antonio, J Int Soc Sports Nutr 2021).
Branched-chain amino acids (BCAAs) are generally considered safe at
standard doses. There are concerns that BCAAs might interfere with some
medications used to treat Parkinson's Disease and might have additive effects
with some medications used to treat type 2 diabetes.
Other muscle enhancing ingredients:
Glutamine at recommended dosages is believed to be
safe. However, it may cause a reaction in people hypersensitive to MSG
(monosodium glutamate). It may also interfere with anti-epilepsy drugs and, in
rare situations, trigger mania in people with bipolar disorder.
HMB is generally considered safe at standard doses.
Taurine is generally considered safe at standard doses.
None of these supplements have been evaluated for safety during pregnancy and
breast-feeding (although taurine is often an ingredient in infant formulas);
therefore, use of these supplements isn't recommended at those times.
Be aware that some muscle enhancement supplements, particularly those marketed
for body building, may contain synthetic stimulants or
steroids which can be dangerous. Distributors of these products
have, at times, misleadingly implied that these are natural, plant-derived
compounds. Examples include the stimulants aegeline
(claimed to be from Aegle marmelos), DMAA
(dimethylamylamine, 1,3 dimethylamylamine
or methylhexanamine) (claimed to be from geranium), DMBA
(1,3-dimethylbutylamine, 2-amino-4-methylpentane or 4-methyl-2-pentanamine and
also labeled on supplements as 4-amino-2-methylpentane citrate, AMP citrate,
1,3-dimethylbutylamine citrate, 4-amino-2-pentanamine, Pentergy,
and 4-AMP, and also claimed to be from Pouchung Tea)
(Cohen, Drug Test Analys 2014; also see the Oct. 9 2014 Warning,
N,N-diethyl-phenylethylamine (claimed to be from dendrobium orchid),
and beta-methylphenethylamine, or BMPEA, (claimed to be from Acacia rigidula).
Animal studies suggest BMPEA could raise blood pressure and have effects
similar to other amphetamine-like substances, although its safety in humans has
not been studied. A 2015 study found two sports supplements listed as
containing Acacia rigidula that
contained an BMPEA (Cohen, Drug Test Analysis 2015).
Sports supplements found to contain BMPEA in the study were:
·
Jet Fuel Superburn (GAT)
·
Jet Fuel T-300 (GAT)
(The same study found a
number of weight loss supplements contained
BDMPEA as well. See the April 8, 2015 Warning for
more details)
Another stimulant found in workout and weight loss
supplements is deterenol, which may be listed on
labels under other names, including isopropylnorsynephrine,
isopropylnorsynephrine HCl, N-isopropylnorsynephrine
HCl and isopropyloctopamine. Deterenol
is not approved in the U.S. for use in humans, either as a prescription drug or
supplement ingredient. Limited studies in people have shown that, in doses
ranging from 2 to 3mg/kg, deterenol tomay cause adverse effects such as flushing, tingling of
extremities and face, anxiety, decreased diastolic blood pressure and increased
heart rate. At a dose of 5mg/kg, it can cause inability to sit up, blurred
vision, palpitations, weakness and respiratory distress. An analysis of 17
brands of supplements labeled as containing deterenol
that are promoted for or may be used as workout supplements confirmed the
following brands contained the drug, in doses of up to 17 mg per serving, and
up to 69 mg per day if used as suggested on the label (Cohen, Clin Toxicol 2021):
·
Cannibal Ferox (Chaos and Pain)
·
Cannibal Riot (Chaos and Pain)
·
Old Jack Extreme multiple flavors (GenOne
Laboratories)
·
TURNITUP multiple flavors (EPG)
·
Edge of Insanity (Psycho Pharma)
Deterenol was not found in one
workout supplement labeled as containing the drug (10 Seconds to Launch,
Avenger Performance Nutrition) although other stimulants were detected
(octodrine, 1,4-DMAA and oxilofrine).
(The same study found a number of weight loss/fat burning supplements also
contained deterenol and/or other stimulants. Also see
the March 26, 2021 warning for more details).
Examples of synthetic steroids include methasterone
and dimethazine. It would seem prudent to avoid
supplements which list any of these ingredients and to favor single-ingredient
products over those with many ingredients, proprietary formulas, and/or those
making extraordinary claims of muscular development and performance. As new,
synthetic compounds continue to be created, it is difficult -- if not
impossible -- for ConsumerLab.com to effectively screen for these in products.
However, the FDA has been actively testing products of concern and
ConsumerLab.com continually posts resulting warnings about specific products.
Many of these postings can be found by searching the term muscle on the ConsumerLab.com website and
then viewing the Recalls and Warnings section near the bottom of the search
results page.
References:
Brose, A et al. Creatine supplementation enhances isometric
strength and body composition improvements following strength exercise training
in older adults. J Gerontol A Biol Sci
Med 2003; 58(1): 11-19.
Burke, DG et al. Effect of creatine and weight training on muscle creatine and
performance in vegetarians. Med Sci Sports Exerc 2003; 35(11):
1946-55.
Fuld, JP et al. Creatine supplementation during pulmonary rehabilitation in
chronic obstructive pulmonary disease. Thorax 2005; 60: 531-37.
Ganguly, S et al. Evaluation of the stability of
creatine in solution prepared from effervescent creatine formulations. AAPS Pharm Sci
Tech 2003; 4(2) Article 25.
Hespel, P et al. Oral creatine supplementation
facilitates the rehabilitation of disuse atrophy and alters the expression of
muscle myogenic factors in humans. J Physiol 2001;
536(Pt 2): 625-33.
Kimball SR, Jefferson LS. Signaling pathways and molecular mechanisms through
which branched-chain amino acids mediate translational control of protein synthesis.J Nutr 2006;
136(1 Suppl): 227S-31S. Negro, M et al. Branched-chain amino
acid supplementation does not enhance athletic performance but affects muscle
recovery and the immune system. J Sports Med Phys Fitness 2008;
48(3): 347-51.
Shimomura, Y et al. Nutraceutical effects of branched-chain amino acids on
skeletal muscle. J Nutr 2006; 136(2): 529S-532S.
Information on this site
is provided for informational purposes only. It is not an endorsement of any
product nor is it meant to substitute for the advice provided by physicians or
other healthcare professionals. The information contained herein should not be
used for diagnosing or treating a health problem or disease. Consumers should
inform their healthcare providers of the dietary supplements they take.
Latest Clinical Research Updates for Muscle & Workout
Supplements (Creatine and BCAAs)
6/19/2021
Can glutamine
supplementation decrease muscle breakdown from exercise? See what a recent
study showed in the What It Does section of our Muscle &
Workout Supplements Review. Also see our Top Picks among muscle and workout products.
Does Creatine Cause Hair Loss?
5/25/2021
Find out if creatine
supplements cause hair loss. See the Concerns and Cautions section of our
Muscle & Workout Supplements Review. Also, see our Top Picks for creatine supplements.
Do Creatine or BCAAs Boost Strength?
12/06/2020
When coupled with
resistance exercise, does supplementation with creatine or branched chain amino
acids (BCAAs) further boost muscle strength? Find out what separate recent
studies showed for creatine and BCAAS in the
"What It Does" section of our Muscle & Workout Supplements Review.
Also, see our Top Pick for creatine and BCAA supplements.
Do Creatine or BCAAs Boost Strength?
12/06/2020
When coupled with
resistance exercise, does supplementation with creatine or branched chain amino
acids (BCAAs) further boost muscle strength? Find out what separate recent
studies showed for creatine and BCAAS in the
"What It Does" section of our Muscle & Workout Supplements
Review. Also, see our Top Pick for creatine and BCAA supplements.
Do Creatine or BCAAs Boost Strength?
12/06/2020
When coupled with
resistance exercise, does supplementation with creatine or branched chain amino
acids (BCAAs) further boost muscle strength? Find out what separate recent
studies showed for creatine and BCAAS in the
"What It Does" section of our Muscle & Workout Supplements
Review. Also, see our Top Pick for creatine and BCAA supplements.