Horny Goat Weed Review: Information and Side Effects!

Posted By elissa on Apr 14, 2010 | 2 comments

Horny goat weed is the common name given to a number of closely-related herbs in the genus Epimedium. The name is derived from the observation of a Chinese goat herder, who noticed his goats would engage in intense sexual activity after eating certain plants.

Also known as “Yin Yang Huo,” horny goat weed is traditionally used as an aphrodisiac, as well as a treatment for fatigue, lower back pain, menstrual irregularities and hypertension.

Horny goat weed contains a number of bioactive components: flavonoids, polysaccharides, sterols, lignans and sequiterpenes. Most of the research is focused on icariin, however, which is considered to be the most active component.

Icariin is a flavonol with a range of interesting properties. Among other things, it can inhibit the activity of an enzyme, phosphodiesterase type 5 (PDE5), which is expressed in penile tissue. PDE5 inhibitors cause blood vessels to relax, which improves blood flow and the ability to sustain an erection.

Not coincidentally, this is how drugs for erectile dysfunction (such as Viagra and Levitra) work.

Thus, icariin (and horny goat weed) may function as a sort of “natural Viagra,” although it’s probably not as potent.

Icariin is also credited with being a “testosterone mimetic” as well as a testosterone booster, which is why standardized horny goat weed extracts are sometimes added to bodybuilding supplements.

These claims are based on only limited research on rats, however. Far more work needs to be done before it can be recommended as a test booster to improve athletic performance and/or muscle mass.

Unfortunately, “limited research in rats” appears to be the norm. Overall, there’s little peer-reviewed human research on either icariin or horny goat weed. Most of the published studies are either in-vitro (i.e., using cultured cells or tissues) or performed in animals (rats or mice).

These experiments offer glimpses of potential benefits… for example, specific studies have revealed that either icariin or epimedium extracts have antioxidant, neuroprotective, antidepressant and anti-aging effects. Nonetheless, these studies are far from conclusive, so it’s premature to assume horny goat weed supplements will have similar effects in humans.

One thing that’s clear is that horny goat weed—despite its reputation as a “male enhancer”—also contains compounds with estrogenic effects. This may explain the ability of extracts to reduce bone loss in animal models of post-menopausal osteoporosis.

This property could make horny goat weed—or icariin—useful for treating osteoporosis in humans, too. A 2007 study conducted in China yielded promising results, although (as usual) more work remains to be done.

Horny goat weed is available in tablets, bulk powders and capsules. It’s often combined with other reputed aphrodisiac herbs (eg., maca) to enhance its effects. Better quality supplements provide extracts standardized for >10% icariin.

No significant side effects have been reported from the use of horny goat weed, beyond a stray report or two. However, as with many herbal supplements, it’s wise to be cautious: pregnant or lactating women should avoid it.

If you’re interested in experimenting with horny goast weed, you have several options. Xtend Life makes a great product called “Male Rejuvenator” that contains a hearty dose. If you’re looking for lower cost options, the Prolab or NOW brands make decent “male enhancement” products worth investigating; all available at one of our recommended online retailers, BodyBuilding.com.