Arginine: The Sexual Supplement?

Arginine has been used as a dietary supplement by bodybuilders and other fitness enthusiasts for almost forever, it seems. Arginine is an essential amino acid, meaning that it must be obtained from food or supplements. The body cannot make arginine on its own.  Arginine is probably best known by fitness enthusiasts because of reports (not generally supported by science) that it might raise growth hormone levels. Truth be told, studies have shown that arginine may raise GH levels; however, it must be injected.  Oral arginine dietary supplements are unlikely to significantly augment GH levels in humans. Its effects on GH levels notwithstanding, arginine has quietly been getting a lot of attention as of late for another reason—its potential for improving sex.

Arginine can expand blood vessels.  This seems to be due to arginine's role in the production of nitric oxide (NO), a well known vasodilator. In men, erections are due in part to vasodilations of various blood vessels in the penis. Thus, theoretically, arginine may be of benefit to those suffering from some forms of erectile dysfunction by augmenting NO levels.  Currently some peer-reviewed studies exist showing that oral arginine supplementation can augment NO levels and enhance the sexual responsiveness of men with some forms of erectile dysfunction. However, it should be noted that studies also exist which find no significant sexual performance enhancement following oral arginine supplementation. Adding to the confusion is evidence hinting that arginine may only work in those whose erectile dysfunction is due to low nitric oxide levels.  In other words, it might not help those whose decreased libido is due to factors other than low NO levels.  Remember, erectile dysfunction is a complex syndrome and may be due to many different factors, both chemical and psychological. Studies showing a positive effect from arginine supplementation used 1-6 grams per day.

Some advertisements for libido-enhancing dietary supplements state that they are effective in women as well as men. I am quite skeptical of these claims due to the conflicting results of studies in this area. As a general rule, women get the short end of the stick (pun intended) when it comes to scientific research.

Side Effects and Concerns

Arginine is generally found to be safe for apparently healthy individuals. People using anti-hypertension medications should consult their physician before using arginine because of concern that arginine might affect blood pressure. Arginine is not appropriate for those infected with herpes virus because it might theoretically produce flair-ups of the infection.  Lastly, arginine should not be used by those suffering from sickle cell anemia due its exacerbating effect on this syndrome. 

Bottom Line

Arginine may one day prove beneficial for those suffering from some forms of erectile dysfunction.  I suggest before using arginine supplements, that you ask for published peer-reviewed studies showing the product actually works in humans.

About the author: Joe Cannon, MS, CSCS, is an exercise physiologist, personal trainer, writer and health educator. He is the author of Nutritional Supplements: What Works and Why. A Comprehensive Review from A to Zinc and Nutrition Essentials, a Guidebook for the Fitness Professional. For more information visit his official website www.Joe-Cannon.com or drop Joe an email directly at JoeCannon@rcn.com