Sex supplements: Do these things actually work?

Nearly 200,000 Chinese people immigrated to the United States in the mid-to-late nineteenth century, and some brought along snake oil—a folk medicine made from the oil of the Chinese water snake. Rich in omega-3 fatty acids, Chinese people used it to treat inflammation for centuries. When Chinese workers shared the oil with their American counterparts, the Americans were reportedly amazed with its health effects. Soon snake oil knock-offs were being sold everywhere, and a cottage industry was born.

These inauthentic snake oils, at best, offered a placebo effect. But keep in mind that the placebo effect can be a powerful thing. The placebo effect of Viagra, for example, is more than 30%, which suggests that the brain has a lot to do with sexual stimulation and function. Although Viagra requires a prescription, there are countless non-prescription sexual supplements (ie, health supplements) available at your local store that also claim to help increase libido or sexual endurance.

However, nobody monitors sexual supplements, which is what makes them scary. The FDA warns that these supplements may contain prescription drug ingredients, controlled substances, as well as untested and unstudied pharmaceutically active ingredients. It issues extra caution concerning sexual supplements (they even use an exclamation point in their official warning):

“These deceptive products can harm you! Hidden ingredients are increasingly becoming a problem in products promoted for sexual enhancement.”

As can probably be expected, little research has been done on sexual supplements. Of the many pills and potions being touted as sex enhancers, only a handful have been studied in any capacity.

Ginseng

Ginseng is the most common ingredient included in the top-selling sexual supplements. In addition to being used as an aphrodisiac, ginseng is theorized to improve sexual function by inducing relaxation of the smooth muscles of the corpus cavernosum via the nitric oxide pathway. However, the side effects of ginseng include headache, upset stomach, constipation, lower blood sugar, and more. These adverse effects don’t bode well for the bedroom.

Fenugreek

Fenugreek is found in one-third of the top-selling sexual supplements created for men and is likely safe. Also known as “methi,” fenugreek is believed to improve hormonal regulation, with possible effects on male sexual health. In one study, researchers found that its use was associated with improved sexual arousal and orgasm, with no adverse effects.

L-arginine

L-arginine is the amino acid used to make nitric oxide, a molecule that facilitates the flow of blood to the penis during an erection, and is the most common amino acid found in sexual supplements. It’s unclear, however, whether a pill form of L-arginine helps with sexual stimulation. Moreover, people with heart disease shouldn’t take L-arginine.

Yohimbe

Yohimbe is an evergreen tree found in Western Africa. Its bark is used to make extracts, tablets, and capsules, which are used to treat erectile dysfunction. Yohimbine hydrochloride is available as a prescription medication in the United States. Adverse events are rare, but its most common side effects include headache, sweating, agitation, hypertension, and insomnia. Yohimbine is contraindicated in patients taking tricyclic antidepressants, antihypertensives, and central nervous system stimulants.

Dehydroepiandrosterone (DHEA)

DHEA is a natural steroid prohormone in the body that declines with age. Some research suggests that DHEA increases libido in women and helps erectile dysfunction in men. Other research indicates that while DHEA supplementation appear to be safe, it fails to budge hormone levels.

Tribulus

Tribulus is an invasive plant species in North America and goes by the name bindii, goat’s head, or devil weed. Although it has boosted sexual activity in animal models, no effects have been demonstrated in humans. Moreover, there have been two reported cases of tribulus-induced severe liver and kidney toxicity following high doses in young men.

Horny goat weed

Although horny goat weed (ie, epimedium) has not been shown to boost sexual activity in humans, it is generally safe for use in its unadulterated form, with only mild adverse effects like increased heart rate and hypomania. In other words, horny goat weed is likely ineffective, despite its suspected action as a phosphodiesterase inhibitor and, of course, its promising name.

Zinc

Although safe, zinc, which is also commonly found in many sexual supplements, is unlikely to boost sexual function. Moreover, zinc deficiency is rare, so most people don’t need this nutrient supplemented.

Maca

According to animal models, maca use was associated with a boost in sexual behavior (muskrat love?). But it has no demonstrable sexual effect in humans. For the most part, the vegetable maca is associated with only uncommon adverse effects, such as mildly elevated liver enzyme and blood pressure levels.

Ginkgo biloba

Ginkgo biloba is advertised for all kinds of health benefits, including sexual. However, it has no proven beneficial effect on sexual function. Plus, it can cause headache and seizures, and interfere with the blood thinner warfarin, significantly increasing an individual’s risk of a bleeding adverse event.

Ultimately, other than their placebo effect, many of the supplements sold to boost sexual function are a waste of money. Moreover, these products can contain dubious or dangerous ingredients. Besides prescription medications, the only other proven ways to improve sexual dysfunction are lifestyle changes including diet, exercise, and smoking cessation. In addition, psychological causes of erectile dysfunction—due to anxiety, depression, guilt, stress, or relationship issues—may be improved with counseling.