Sexual Enhancer Supplements Review (with Yohimbe,
Horny Goat Weed, Arginine)
Choose the Best Sexual
Enhancer Supplement. Only 30% of Selected Sexual Enhancement Supplements Pass
Quality Tests.
Medically reviewed and
edited by Tod Cooperman, M.D. 
Last Updated
: 09/11/2020 | Initially Posted:
08/30/2011
Recent Reviews
·
Aloe Juices, Gels, and Supplements
Review
·
NAD Booster Supplements Review
(NAD+/NADH, Nicotinamide Riboside, and NMN)
·
PQQ (Pyrroloquinoline Quinone)
Supplements Review
Table of Contents
Background: Sexual
Dysfunction and Current Drug Therapies:
Sexual dysfunction is a common complaint among both men
and women. By some estimates, over 40% of American women suffer from a loss
libido, difficulty reaching orgasm, or other sexual troubles. Meanwhile, more
than 30% of all men have trouble achieving or keeping an erection, a condition
known as erectile dysfunction. In both men and women, sexual stimulation causes
activity in the nervous system which, in turn, causes local release of nitric
oxide in the genitals, stimulating a substance called cGMP that increases blood
flow causing sexual arousal an erection in men and clitoral enlargement in
women. The biochemical steps that lead to orgasm, however, are poorly
understood. Viagra and similar drugs block the breakdown of cGMP in the penis
specifically. The net effect is to increase cGMP's effect in the penis,
increasing blood flow to the penis during arousal, producing a more lasting and
possibly more complete erection than would otherwise occur. To clear up a
common misunderstanding, these drugs do not cause instant erections. If a man
isn't aroused, he won't be making any extra cGMP and blood won't rush to his
genitals. Viagra was the first breakthrough treatment for erectile dysfunction,
but it and similar drugs like Cialis and Levitra have limitations that only
increase the appeal of natural alternatives. They can be expensive costing as
much as $10 per pill and are often not covered by medical insurance. They
should be avoided completely by men taking medicines that contain nitrates such
as nitroglycerin because the combination can cause a dangerous drop in blood
pressure. They can cause mild to moderate side effects such as headache and
visual disturbances. In rare instances, men have reported erections that last
many hours, which is painful and can potentially damage the penis. Heart
attack, stroke, irregular heartbeats and death have also been reported rarely
in men taking Viagra, although it is not possible to determine whether these
events were directly related to the drug. Although the search continues, there
are no impressively successful prescription drug treatments for female sexual
dysfunction.
The Evidence for
Supplements for Sexual Enhancement:
Many
supplements have been touted as natural remedies for sexual dysfunction. These
products contain a wide array of herbal and other ingredients. As the summary
below makes clear, there isn't much sound clinical evidence to support the use
of most of these ingredients. This does not necessarily mean that they don't
work, just that they are so far unproven. Without well-designed clinical
studies, it's hard to know the appropriate doses or potential safety concerns.
Be aware that supplements often combine ingredients in a product, making the
end results even less predictable unless that specific combination has been
tested. Sexual dysfunction is one matter. Numerous products, often sold on the
web, also claim to enlarge the size of the penis. Such claims are completely
unfounded. There is no way short of surgery to increase a man's natural penis
size. Many of the "penis enlargement" products claim the same
ingredients found in products for treating erectile dysfunction. At best, these
products will only help with an erection -- a temporary increase in penis size.
It should also be noted that some natural products may actually decrease
libido. For example, soy isoflavones and licorice may lower testosterone in
men, and the supplement androstenedione may raise estrogen levels in men
without raising testosterone; either of these effects could lead to reduced
libido in men. Arginine:
One of the more popular supplement ingredients for sexual dysfunction is the
amino acid L-arginine, also referred to as arginine. Arginine helps the body
produce nitric oxide, a compound that helps relax blood vessels and increase
blood flow. It has been hypothesized that taking high levels of arginine could
increase blood flow to the genitals during arousal by increasing nitric oxide
levels. However, in some pharmaceutical studies leading up to the creation of
Viagra, drugs that increased the levels of nitric oxide in the penis were not
found to be effective; rather, it was found necessary to increase sensitivity
to the rise of nitric oxide. The body may simply accommodate to higher
background levels of nitric oxide.
Arginine might offer modest benefit for sexual dysfunction in men. A
double-blind, placebo controlled trial of 50 men with erectile dysfunction
tested arginine at a dose of 5,000 mg per day for six weeks. About a third of
the participants who received arginine showed improvement. For comparison, 11%
of men taking a placebo said they also noticed an improvement (Chen, BJU Int 1999). But
the studies are a mixed bag. Whether scientists are testing humans or rats,
arginine seems to work in some trials but not in others.
Although arginine alone has not been studied as a
treatment for sexual dysfunction in women, a small but reasonably
good double-blind trial found evidence for benefit with a combination formula (ArginMax for Women) providing a daily dose of 2,500 mg of
L-arginine, as well as amounts of Panax ginseng, Ginkgo biloba extract,
damiana, plus numerous vitamins and minerals. In a four-week, double-blind
study, 77 women with decreased libido were given either the combination product
(ArginMax) or placebo. Over 70% of them women taking ArginMax reported an increase in sexual desire, compared
with over 40% of women taking a placebo. (The placebo effect is notoriously
strong for such conditions. Simply believing that a pill will increase desire
or satisfaction can become a self-fulfilling prophecy.) Other reported benefits
included: relative satisfaction with sex life (74% vs. 37%), improved frequency
of orgasms (47% vs. 30%), and improved clitoral sensation (53% vs. 35%). No
significant side effects were seen. (Ito, J Sex Marital Ther 2001).
There have been other studies of arginine for sexual dysfunction in women, but
because they were not double-blind, placebo-controlled trials, they are of
little scientific value.
L-arginine has other documented uses, including the treatment of congestive
heart failure. See ConsumerLab.com's separate Product Review of L-Arginine Supplements for
more about this compound and tests of additional arginine products.
Yohimbe:
Yohimbe is made from the bark of the Pausinystalia
johimbe tree found in Africa. It contains
the chemical yohimbine which is an FDA-approved drug that is marginally
effective for male erectile dysfunction along with additional alkaloids and
other compounds from that occur in yohimbe bark. Yohimbine is believed to act
through the nervous system to increase blood flow to the penis. Most clinical
studies have been conducted with isolated yohimbine HCl rather than yohimbe
bark or bark extract. In the pharmaceutical market, Viagra and related drugs
have almost entirely superseded yohimbine for reasons of safety and
effectiveness (See Concerns and Cautions).
Yohimbe is sometimes promoted an aphrodisiac that can enhance libido. The
compound yohimbine itself is not known to have this effect.
Ginseng (see ConsumerLab.com's Ginseng Product Review for additional
information)
The herb Panax ginseng has a traditional reputation for
enhancing sexual function in men. Two studies enrolling a total of 135 men
support this use for a particular form of ginseng: the steamed and heat-dried
product called red ginseng. One of these studies was a 3-month double-blind,
placebo-controlled trial that evaluated the effects of Korean red ginseng in 90
men with erectile dysfunction. Participants received either red ginseng at a
dose of 1,800 mg daily, the drug trazodone (an antidepressant with marginal
effects on erectile dysfunction) or placebo. The results indicated that red
ginseng worked better than both the placebo and trazodone treatments (Choi, Int J Impot Res 1995). Contrary to some
reports, ginseng does not appear to affect estrogen or testosterone levels or
mimic their effects.
More recent studies have looked at the role of even higher doses of red ginseng
in sexual function. One study in Brazil examined the effects of 3,000 mg of red
Korean ginseng versus placebo in men with mild to moderate erectile
dysfunction. Sixty-six percent of the men using ginseng saw an improvement in
their erections while there was no significant improvement among men receiving
placebo (de Andrade, Asian J. Anrdol.
2007).
Korean red ginseng may also improve some, but not all, measures of sexual
function in women. A double blind, placebo-controlled cross-over study in Korea
comparing the effects of 3,000 mg of red ginseng to placebo in 28 women
(average age 51 years old) found a significant improvement in arousal. No
severe side effects were reported although 2 women experienced vaginal bleeding
while taking the ginseng product (Oh, J Sex Med 2010). Another double-blind, placebo-controlled study in
Iran among 32 women (average age 37) complaining of sexual dysfunction found
that those given one tablet of the product X-Ade (Golden Life)
providing 67 mg of Korean ginseng, 40 mg of eleuthero, and 100 IU of vitamin E
daily after lunch for 6 weeks reported a two-fold greater improvement in both
"desire" and "satisfaction" compared to those given
placebo. However, overall sexual function (which was the primary focus of the
study), as well as arousal, lubrication, orgasm and pain were not improved for
those who were supplemented compared to the placebo group, although both groups
showed significant improvement in these measures compared to baseline. No
serious side effects were reported (Ghamari, Women Health 2020).
Maca (Lepidium meyenii)
The herb maca is widely sold as an aphrodisiac. In one small double-blind,
placebo-controlled study, use of maca at 1.5 or 3 grams daily seemed to enhance
male interest in sex. The effects on erectile function were not studied. (Gonsalez, Andrologia 2002).
For more information and tests of maca supplements, see the Review of Maca Supplements.
Proprietary Combination of Epimedium (Horny goat weed or Epimedium
grandiflorum) maca, dopa bean (Mucuna pruriens or velvet bean)
and polypody (Polypodium vulgare)
The herbs in this frequently cited combination formulation each have a
reputation for male sexual enhancement. While there is little meaningful
supporting evidence for any one of them individually (except maca, as described
above), one unpublished trial conducted by Dr. Stephen Lamm
provides an inkling of evidence for the combination. The first part of the
study was not double-blind, however, and therefore indicates nothing about the
effect of the treatment. However, after that portion of the study was
completed, 13 men who had reported enhanced sexual function from the
combination were randomly assigned to receive either the herbal combination
(808 mg twice daily) or a placebo for a period of 15 days.
The results showed that 6 out of 7 men given the active treatment experienced a
continuation of the improvement in sexual function, while none of the men given
placebo did so. However, no statistical analysis was performed. Nonetheless,
the apparently positive results of this trial may suggest that the combination
therapy should be investigated further. None of the herbs in this combination
have undergone comprehensive safety testing (see Concerns and Cautions).
Butea superba
According to a small double-blind study performed in Thailand, the herb Butea
superba may enhance erectile function.
OPCs
OPCs (oligomeric proanthocyanidins),
substances found in grape seed and pine bark, have shown some promise for
erectile dysfunction in preliminary trials.
Vitamin C (see ConsumerLab.com's Vitamin C Product Review for additional
information).
One double-blind study suggests that vitamin C at a high dose of 3 grams daily
might increase female libido.
Ashwagandha (see CL's Review of Ashwagandha Supplements for
more information)
One double-blind study in women found ashwagandha extract improved overall
sexual function (arousal, lubrication and satisfaction), but did not increase
sexual desire, compared to placebo. In men, a double-blind study ashwagandha
extract increased testosterone levels, as well as sperm concentration, volume
and motility, compared to placebo.
Many herbs and other natural products end up in sexual enhancement products
despite a little evidence that they have any effect. Some of these ingredients
may have other, better-studied, applications that are discussed in more detail
in other Product Reviews (indicated below) in which products have been tested.
Ginkgo (see CL's Product Review of Ginkgo Biloba for more
information)
Case reports and open trials had suggested that Ginkgo biloba may
be an effective treatment for antidepressant-induced sexual dysfunction in both
men and women. However, the two properly designed double-blind studies on the
subject failed to find ginkgo more effective than placebo.
St. John's Wort (see CL's Product Review of St. John's Wort, for
more information)
An uncontrolled study found that use of the herb St. John's wort improved
sexual function in post-menopausal women; these are essentially meaningless
results, however, as placebo can also be expected to improve sexual function.
Deer Velvet Antler
One study failed to find deer velvet antler more effective than placebo for
enhancing male sexual function.
Miscellaneous Ingredients:
The herb Tribulus terrestris (tribulus) is said to increase DHEA levels, so it has been
proposed as a treatment for sexual dysfunction. However, one well-designed study
of tribulus found that it didn't increase sex
hormones in young men, and there is no evidence that it affects human sexual
function.
Extracts of Eurycoma longifolia (Long
Jack or Tongkat Ali) have been shown in animal models
to stimulate sexual activity, and there is some evidence that it may have
testosterone-like effect, although there are no human clinical studies. Animal
tests have also shown toxicity with a certain types of extract, although not
with others.
Other proposed herbs and supplements for sexual dysfunction in men or women
that lack meaningful clinical evidence for efficacy include Eurycoma longifolia, Pimpinella pruacen, Muira puama and damiana, saw palmetto (see CL's Product Review of Saw Palmetto for more
information), codonopsis, schizandra, royal
jelly, Pygeum africanus, catuaba bark, chuchuhuasi bark, abuta, androstenedione, ashwaghanda,
zinc (see CL's Product Review of Zinc), lipoic acid (see
CL's Product Review of Alpha-Lipoic Acid),
gamma-linolenic acid (see CL's Product Review of GLA and other oils for
more information).
ConsumerLab.com focused its testing on products containing one or more of the
most popular and scientifically supported remedies for sexual dysfunction:
L-arginine, yohimbe, and epimedium (horny goat weed).
Quality Concerns and
Tests Performed:
Neither the FDA nor any other federal or state agency routinely
tests supplements for quality prior to sale. In order to help consumers make
informed decisions and identify products of better quality, ConsumerLab.com
tested sexual enhancement products containing yohimbe, epimedium
(horny goat weed), and/or L-arginine in the laboratory to see if they met the
quality standards. See Testing Methods for more details.
Amount of key ingredient
It is important to know that a product contains the ingredient(s) that it
claims. Too little and you may not get the expected benefit as well as waste
your money. Too much, and you may experience negative effects. ConsumerLab.com
identified one or more key ingredients in each product to confirm its identity
and measure the amount in a daily serving.
Unlisted Ingredients:
One concern with sexual enhancement products is the possibility that they may
be "spiked" with unlisted ingredients, including known erectile
dysfunction drugs or their related analogues (chemical variations). The FDA has
issued several warnings in the past two years informing consumers about dietary
supplements that illegally contain sildenafil citrate, the active ingredient in
Viagra or related analogues. We screened all products for signs of such
tampering.
Lead Contamination:
Lead is a potential contaminant in herbal products. In children, infants, and
fetuses, even low levels of lead can adversely affect neurobehavioral
development and cognitive function. In adults, lead at somewhat higher levels
can cause elevated blood pressure, anemia, and adversely affect the nervous and
reproductive systems. Lead is of particular concern during pregnancy as the
mother can transfer it to the fetus. All products were tested for lead.
Tablet Disintegration:
All supplements sold as tablets were tested to see how long the tablets take to
break apart in liquid; if they can't break apart fast enough, less ingredient
may be available for absorption by the body.
What CL Found:
Among the eleven herbal sexual enhancement products that
ConsumerLab.com selected, only three passed testing, as did one supplement
tested through ConsumerLab.com's Voluntary Certification Program. However, all
of the products were free of prescription drugs for erectile dysfunction and
known analogues of those drugs, and all tablets were able to properly break
apart.
Yohimbe:
Of three products marketed specifically as yohimbe supplements, only one passed
testing -- Swanson Superior Herbs Yohimbe, which provided the
claimed 10 mg of yohimbe alkaloids per capsule, of which 4.5 mg was yohimbine.
SciFit Massive Yohimbe Bark contained
only 11% of the claimed 24 mg of yohimbine. However, that adds up to 4.7 mg if
you take the suggested serving of 2 capsules, which is actually slightly more
than you'd get from the recommended one capsule of the Swanson product.
Ultimate Nutrition Yohimbe Bark Extract contained just half its
claimed amount of yohimbine -- a mere 0.25 mg per mL of liquid. Although
labeled as dietary supplement, the directions on the bottle state that it
should be given sublingually (under the tongue). Technically, products taken
like this are considered to be drugs rather than dietary supplements. Taking a
product sublingually is meant to send its active ingredients directly into the
blood rather than the through the digestive system. Not only is this product
considered an unapproved drug based on its suggested use, but it is uncertain
how well yohimbine would actually be absorbed under the tongue.
One of the combination products, ExtenZe,
was also tested for its yohimbe content. It claimed that one tablet provided
12.5 mg of yohimbe alkaloids, a family of compounds that includes yohimbine.
ConsumerLab.com found only 7.9 mg of the alkaloids -- 63% of the claimed
amount. Of this, 3.4 mg was yohimbine. The product did, however, contain its
listed amount of DHEA (45 mg). (In case you are wondering what "ambesium labidrol" means
in the ExtenZe product name, these
words have no scientific meaning and seem to be a marketing gimmick, perhaps to
give the product a more scientific aura. (Note: In early in 2011, the FDA
announced a recall of certain
lots of counterfeit ExtenZe which contained
prescription drugs for erectile dysfunction.)
Update (9/30/15): The high rate of problems identified with
yohimbe products in this Review is consistent with findings from a more recent
academic study in which 49 yohimbe-containing products were analyzed using
similar methods to those used in this Review. Only 11 products listed a
specific quantity of yohimbine and, among these, only 3 were accurately
labeled while 6 were low (23% to 69% of amount listed) and two were high (142%
and 147%). Across all products, amounts of yohimbine per suggested serving
ranged from none to 12.1 mg -- and up to 15.3 mg per day. The paper
does not disclose names of products (Cohen, Drug Test Analysis 2015).
Epimedium (Horny goat weed):
None of the four products specifically marketed as horny goat weed passed our
review -- although some combination products did pass tests for horny goat
weed. Maximum International Horny Goat Weed was disqualified
from testing for not indicating the part of the plant used, a violation of FDA
labeling rules. The same was true of a combination product Excite (Dymatize Nutrition).
Planetary Herbals Full Spectrum Horny Goat Weed appeared to contain
its listed amounts of the herb (1,000 mg of extract and 200 mg of leaf) but was
contaminated with lead at a level that would require a warning label under the
California Prop 65 law. NOW Horny Goat Weed Extract contained
only about 10% of its listed amount of horny goat weed, judging from tests
measuring levels of a marker compound (icariin).
Two combination formulas also listed specific amounts of horny goat weed.
Both BodyTech LongJax
MHT with Arginine and Magna-RX+ each contained their listed amounts of
horny goat weed, judging from the measured levels of icariin. BodyTech contained the larger amount of horny
goat weed 500 mg to 1,000 mg per day and also contained its claimed amount
L-arginine (250 mg per capsule). Magna-RX+ provided 232 mg per
day of horny goat weed.
L-Arginine:
Natrol's L-Arginine Erectile Function (EF) formula
(which provides L-arginine along with three B vitamins) passed testing for its
L-arginine content. BodyTech, as noted earlier, also
contained its claimed amount of L-arginine. (See separate Product Review of L-Arginine Supplements for
tests of additional L-arginine supplements).
Can any of these products actually help?
Only four products passed all phases of testing. Swanson Superior Herbs
Yohimbe, BodyTech LongJax
MHT with Arginine, Magna-RX+, and Natrol
L-Arginine. In addition to containing the ingredients for which they
were tested, none were contaminated with lead and all were free of sexual
enhancement drugs and known analogues. But whether these or any other natural
product can actually help anyone dealing with sexual dysfunction remains an
open question.
As discussed further in the ConsumerTips section
below, there's some evidence that 5.4 mg of yohimbine taken three times daily
may help with male erectile dysfunction. The Swanson product
provided a somewhat smaller amount 4.5 mg per capsule but it's possible that it
may have some effect.
The BodyTech product provided 500 mg
to 1,000 of both L-arginine (500 mg to 1,000 mg) and horny goat weed in its
suggested dose of two to four capsules daily. Studies of arginine by itself
suggest that you'd need a lot more than 1,000 mg to have any effect 5,000 mg is
the amount shown to have an effect on its own. An effective dose of horny goat
weed, if there is one, is not known. It is possible that these and the other
ingredients in BodyTech -- Eurycoma longifolia (Long Jack), Tribulus terrestris, and maca may have some combined effect, but
without clinical evidence it's only conjecture.
Magna-Rx+ contains very small amounts of both L-arginine and horny
goat weed. It seems unlikely that it would have an effect on sexual
enhancement. Its many other claimed ingredients, such as ginseng, may have some
effect, but there is no clinical evidence to support this combination of
ingredients.
Natrol L-Arginine contained its
3,000 mg per daily serving of 3 tablets. However, as noted above, the amount of
L-arginine shown to work clinically for erectile dysfunction has been 5,000 mg,
so it is unclear if this Erectile Function formula would be effective. The significance
of its additional B vitamins is probably of no benefit unless you are deficient
in B vitamins.
The bottom line: There is little clinical evidence suggesting that
any of the products that we tested would improve anyone's sexual functioning at
the suggested doses. Still, there may be some activity from these products and
some people may therefore notice an improvement.
Test Results by Product:
Listed
below are results of the evaluation of eleven different products containing one
or more ingredients used as sexual enhancers. Products are shown alphabetically
by category. ConsumerLab.com selected ten products. One other product
(indicated with an asterisk) was tested at the request of its distributor
through CL's Voluntary Certification Program and
is included for having passed testing.
Also shown are the claimed amount and form of the tested ingredient(s) and
serving sizes recommended on labels. Products listed as "Approved"
met their label claims and ConsumerLab.com's quality
criteria (see Passing Score). The full list of ingredients
is available for each product by clicking on the word "Ingredients"
in the first column.
|
CONSUMERLAB.COM RESULTS FOR SUPPLEMENTS USED FOR SEXUAL
ENHANCEMENT (L-ARGININE, YOHIMBE, AND HORNY GOAT WEED) |
||||||
|
Horny Goat Weed (Epimedium) Products: |
||||||
|
Product Name and
Suggested Daily Serving
|
Claimed Amount of
Horny Goat Weed (and Icariin) Per Suggested Daily Serving on Label |
OVERALL RESULTS:
APPROVED (Passed) or NOT APPROVED (Failed) |
Contained Expected
Ingredients |
Did Not Exceed Conta-mination Limits for Lead |
Free of Drugs for
Erectile Dysfunc-tion*** |
Daily Cost |
|
Maximum International Horny Goat Weed |
Horny Goat Weed: 1,000 to 2,000 mg (Icariin: 5
to 10 mg) |
NOT |
Not tested due to
insufficient labeling |
$0.90 |
||
|
NOW Horny Goat Weed Extract |
750 mg extract |
NOT |
Icariin: 7.7 mg (10.3%) |
|
|
$0.13 |
|
Planetary Herbals Full Spectrum Horny Goat
Weed |
1,000 mg extract and 200 mg leaf [12 mg
icariin |
NOT |
Icariin: |
Found 1.5 mcg of lead
per daily serving |
|
$0.30 |
|
Yohimbe Products: |
||||||
|
Product Name and
Suggested Daily Serving
|
Claimed Amount of
Yohimbe Bark Extract Per Suggested Daily Serving on Label |
OVERALL RESULTS:
APPROVED (Passed) or NOT APPROVED (Failed) |
Amount Found per Daily
Serving of Yohimbe Alkaloids (and Yohimbine) |
Did Not Exceed Conta-mination Limits for Lead |
Free of Drugs for
Erectile Dysfunc-tion*** |
Daily Cost |
|
SciFit Massive Yohimbe Bark |
Yohimbe extract: 1,200 mg |
NOT |
Alkaloids: 6.7 mg |
|
|
$0.16 |
|
Swanson Superior Herbs Yohimbe |
Yohimbe extract: 500 to 1,000 mg |
APPROVED |
Alkaloids: |
|
|
$0.07 - $0.13 |
|
Ultimate Nutrition Platinum Series Yohimbe
Bark Extract |
Yohimbe extract: 25 to 50 mg |
NOT APPROVED5 |
Alkaloids: 0.35 - 0.7
mg |
|
|
$0.14 - $0.28 |
|
Combination Products with L-Arginine, Horny
Goat Weed and and/or Yohimbe |
||||||
|
Product Name and
Suggested Daily Serving
|
Claimed Amount Per
Suggested Daily Serving, Or Minimum Expected Amount (M) if Not Claimed, of: |
OVERALL RESULTS:
APPROVED (Passed) or NOT APPROVED (Failed) |
Contained Expected
Ingredients |
Did Not Exceed Conta-mination Limits for Lead |
Free of Drugs for
Erectile Dysfunc-tion*** |
Daily Cost |
|
BodyTech LongJax MHT with
Arginine |
L-Arginine: 500 to 1,000 mg |
APPROVED |
L-Arginine: |
|
|
$0.77 |
|
Excite (Dymatize
Nutrition) |
Horny Goat Weed: 500 to 1,000 mg extract |
NOT |
Not tested due to
insufficient labeling |
$0.39 |
||
|
ExtenZe (ambesium labidrol) |
Yohimbe extract: Not Listed |
NOT APPROVED |
Alkaloids 7.9 mg (63%) |
|
|
$0.80 |
|
Magna-RX+ |
L-Arginine: 118 mg |
APPROVED |
L-Arginine: |
|
|
$1.40 |
|
Natrol L-Arginine 3000 mg, Erectile Function (EF)
Formula |
L-Arginine: 3,000 mg |
APPROVED |
L-Arginine: |
|
|
$0.32 |
|
* Tested through CL's Voluntary
Certification Program prior to, at time of, or after the
posting of this Product Review. |
||||||
|
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, 2011. All rights reserved.
Not to be reproduced, excerpted, or cited in any fashion without the express
written permission of ConsumerLab.com LLC. |
||||||
ConsumerTips™:
What to
Consider When Buying:
Epimedium (Horny goat weed)
The Supplement Facts section of the label may include the scientific name for epimedium which can be Epimedium grandiflorum Morr. (barrenwort), Epimedium brevicornum Maxim.
(epimedium), Epimedium koreanum
Nakai (epimedium),
or Epimedium sagittatum. The label should
specify that the product contains dried aerial parts of the plant (leaves and
some stems/stalks). Often epimedium in supplements is
in the form of an extract. Preferably, this is standardized to contain a
certain amount (typically 8% to 10%) of icariin a marker compound for epimedium. This standardization may be expressed as a
percentage, such as 10% icariin, or as an amount such as 25 mg icariin in 250
mg of epimedium herb extract (equivalent to 10%
standardization).
If epimedium herb powder (as opposed to extract) is
used, it will be less concentrated than the extract (typically 1% to 3% for the
herb), with a lower percentage of active compounds, so higher amounts would be
needed to be equivalent to an equal weight of extract.
Be aware that the description 10% flavonoids as icariin on a label does not
mean that 10% of that ingredient is icariin. It means that any flavonoid
compound found in that ingredient is being considered to be icariin. This is
not an accurate way to describe icariin content. To help correct for this, we
still required that a minimum of 1% of any epimedium
ingredient be icariin.
Yohimbe
The Supplement Facts section of the label may include the scientific name for
yohimbe which can be either Pausinystalia
johimbe K. Schum or Corynanthe
yohimbe K. Schum (yohimbe). The label should specify that the product
contains either bark or bark extract. Often yohimbe bark in supplements is in
the form of an extract. This extract is preferably standardized (typically 2%
to 6%) to contain a certain amount of the active compounds known as
"yohimbe alkaloids" or "yohimbine." The amount of yohimbine
is 10% to 15% of the total yohimbe alkaloids. Care must be taken when reading
the labels, as the standardization may be expressed as a percentage, such as
"2% yohimbine," or as an amount such as "8 mg yohimbine in 400
mg of yohimbe bark extract" (which may also be listed as a 2%
standardization). If only yohimbe bark powder (and not "extract") is
used, it will be less concentrated than the extract with a lower percentage of
active compounds, so higher amounts would be needed to be equivalent to an
equal weight of extract.
Epimedium (Horny goat weed)
Like yohimbe and other herbal products, to help assure that you are getting the
right herb, expect to find the following name and plant part in the Supplement
Facts list of ingredients: Name: Epimedium grandiflorum Morr. (barrenwort), Epimedium brevicornum Maxim.
(epimedium), Epimedium koreanum
Nakai (epimedium),
or Epimedium sagittatum; Plant part:
Dried aerial part of the plant (leaves and some stems/stalks). Often epimedium in supplements is in the form of an extract.
Preferably, this is standardized to contain a certain amount (typically 8% to
10%) of icariin a marker compound for epimedium. This
standardization may be expressed as a percentage, such as 10% icariin, or as an
amount such as 25 mg icariin in 250 mg of epimedium
herb extract (which would also be a 10% standardization). If only epimedium herb powder is used, it will be less concentrated
than the extract (typically 1% to 3% for the herb), with a lower percentage of
active compounds, so higher amounts would be needed to be equivalent to an equal
weight of extract.
Arginine (See Product Review of L-Arginine Supplements)
What to Consider When Using:
Epimedium (Horny goat weed):
Optimal doses for horny goat weed have not been well established. Products
typically suggest a dose of 500 to 1,000 mg per day, standardized to 10%
icariin a marker compound for epimedium.
Yohimbe
A typical dosage of yohimbine (one of the active chemicals in
yohimbe) for erectile dysfunction is 5.4 mg three times daily, preferably after
meals although one of the doses may be taken before bedtime for overnight
activity. Higher doses are not necessarily more effective than lower ones; in
fact, for some people the reverse is true. If side effects occur (see Concerns and Cautions below), it is
advisable to reduce the dose by half. Since yohimbine is only a small
percentage of the weight of yohimbe bark powders or extracts, it takes a large
dose to get a small amount of the active ingredient. For example, to yield a
5.4 mg dose of yohimbine, you would need, approximately 1,350 mg of a yohimbe
bark extract standardized to 4% yohimbe alkaloids (yohimbine is approximately
10% of the total yohimbe alkaloids) or about 2,700 mg of a yohimbe bark extract
standardized to 2% yohimbe alkaloids.
The combination of yohimbine plus arginine has shown some promise for treatment
of sexual dysfunction in women. In a small double-blind, placebo-controlled
trial, participants with sexual arousal disorder were given a one-time dose of
yohimbine (6 mg) plus arginine (6 grams); yohimbine alone, or placebo. Testing
showed that the combination therapy enhanced physiological response to visual
sexual stimulus as compared to placebo; however, yohimbine alone did not
produce superior effects to placebo.
Arginine
In studies of arginine for sexual dysfunction in women, typical dosages have ranged
from 2,500 to 6,000 mg daily. In men, some evidence suggests that 5,000 mg
daily may be effective, while 1,500 mg daily is not. Results may take up to
four weeks.
Concerns and Cautions:
Arginine
In clinical trials, use of oral arginine in healthy individuals has not been
associated with any serious adverse effects, other than occasional mild stomach
upset. It has been suggested (but not proven) that high dose oral arginine may
increase stomach acid levels and worsen esophageal reflux (heartburn). For this
reason, individuals with ulcers or esophageal reflux should use caution when
taking arginine. In addition, individuals taking medications that irritate the
stomach, such as NSAID drugs (medications in the aspirin/ibuprofen family)
might increase their risk of developing ulcers if they take arginine as well.
Arginine may improve the body's ability to respond to insulin. This could be a
benefit, but it could cause problems in individuals taking medications for
diabetes. Arginine should not be recommended for people who have had an acute
myocardial infarction because as one study showed an increase in deaths in such
people taking arginine versus those who took placebo.
Arginine may cause a mild reduction in blood pressure, but studies have not
shown a consistent effect. Out of caution, it may be best to avoid using
arginine with supplements and medicines that may lower blood pressure,
including sildenafil (Viagra) and tadalafil (Cialis) (Wallace, Anesth
Analg 2000). However, two small,
preliminary studies in men suggest that taking arginine with sildenafil
(Viagra) may be safe (Mantovani, Minerva Urol Nefrol 2001; Tom, American Society of
Anesthesiologists 2001).
Epimedium (Horny Goat Weed)
According to one case report, use of Epimedium grandiflorum (horny
goat weed) caused rapid heart rate and mania in a person with bipolar disease.
A study in rats suggests that taking Epimedium grandiflorum with
sildenafil (Viagra) may decrease the effectiveness of the drug (Hsueh, Molecules 2013).
Epimedium combinations
None of the herbs in combination with horny goat weed have undergone
comprehensive safety testing. One of them, Mucuna pruriens, is a
natural source of the drug levodopa (l-dopa); this
drug, used for Parkinson's disease, has a number of potential risks and side
effects.
Yohimbe
The most common side effects of yohimbe supplementation are increased
blood pressure, anxiety, and increased frequency of urination. Increases in
blood pressure typically begin at a dose of about 20 mg or more of yohimbine
with greater increases with higher doses (Tam, Pharmacol Ther 2001).
A 49-year-old man with pre-existing, untreated
hypertension was admitted to the hospital with very high blood pressure (280/142
mm Hg) and symptoms such as lightheadedness and anxiety after
taking two capsules of a sexual enhancement supplement containing yohimbe. He
was treated with medication to lower his blood pressure and released from the
hospital the following day with instructions to avoid yohimbe. The supplement
contained 62.5 mg of yohimbe bark extract and 5 mg of yohimbine alkaloid per capsule
and the man had taken two capsules that morning. The supplement was not named
in the report (Prescott, J Emerg
Med 2019), but the yohimbe content is similar, for example, to that listed
in a product like GNC's Maca Man Advanced Sexual Health Formula For Men,
which includes additional ingredients (maca root, niacin, Ginkgo biloba, and L-arginine). One death
has been linked to high blood pressure and seizures that occurred in an
individual taking high doses of yohimbe, and other adverse effects
including rash, nausea, rapid heartbeat, atrial fibrillation, headache,
confusion and loss of consciousness have been reported (Anderson, J Anal Toxicol 2013).
+ 14 sources
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 Sexual Enhancers
6/01/2019
Yohimbe is a common
ingredient in certain supplements for men but can be dangerous, as evidenced by
recent report. Get the details in the Concerns and Cautions section
of the Review.
9/30/2015
Yohimbe supplements
contain an active compound, yohimbine, which is an old drug for erectile
dysfunction. A recent study found that most yohimbe supplements don't list the
amount of yohimbine they contain, and those that do are typically inaccurate —
similar to what ConsumerLab.com has found. For more about the study as well as
our own tests of products, see the Sexual Enhancement Supplements
Review >>
Related CL Answers (5)