Many men yearn for a better sex life, at least if the growing number of ads and websites promoting performance-boosting supplements is any measure. The formulas go by names such as ExtenZe, Stay Erect, X-Rock, Endowmax, Enzyte and ArginMax. Some are marketed as “natural alternatives” to Viagra (sildenafil) and other drugs used to treat erectile dysfunction—the repeated inability to have and/or maintain an erection sufficient for sexual intercourse. Others make vaguer claims about improving sexual performance (“drive women wild in bed”) or none-too-subtle promises about enlarging penis size.
An erection depends on many factors, including blood supply, hormones, and nerve and muscle tissue in the penis. Some ingredients found in the supplements are supposed to affect these factors, and in a few cases there’s a theoretical basis for a possible benefit. But most products contain a witch’s brew of ingredients that range from dubious to outright dangerous. The labels often don’t tell you exactly what’s inside, and rarely in what amounts. Even if they do tell you, they may not be accurate.
Here are some common ingredients marketed as sexual performance boosters.
Arginine: This amino acid, one of the building blocks of protein, enhances the effects of nitric oxide, a chemical that improves blood circulation in the body. Nitric oxide also relaxes blood vessels and smooth muscles in the penis, thus producing erections. This is also what erectile dysfunction drugs do. But it’s unknown whether enough of the supplemental arginine gets into the penis to make a difference. Indeed, some studies have found little or no improvement compared to a placebo.
Ginseng: Long regarded as an aphrodisiac in Asia, this herb is claimed to improve erections by dilating blood vessels and affecting nerves involved in erections. A big problem with ginseng is its great variability. Not only are there several types, which have different compounds and biological properties, but different parts of the plants are used and these also contain varying compounds. Preliminary research suggests that Korean red ginseng may improve erectile dysfunction; other forms may not have this effect.
Prohormones: Many prohormones (hormone precursors), which are supposed to boost testosterone, are marketed as sex drive enhancers as well as muscle-building aids. In 2005, U.S. federal law banned over-the-counter sale of 25 of these compounds, including androstenedione, because of serious risks. These are now controlled substances, like anabolic steroids. Marketers have wiggled around the law, however, and produced other “natural testosterone boosters.” Two are DHEA (dehydroepiandrosterone) and the herb Tribulus terrestris. It’s unclear how effective any of these are, if at all. If they do act like testosterone or affect other hormones, they could have serious long-term adverse effects.
Yohimbe: Made from the bark of a West African tree, this has been used as an aphrodisiac for centuries. In pre-Viagra days, it was sometimes prescribed to treat erectile dysfunction. A standardized extract is still available by prescription, though little used today. Yohimbe dilates blood vessels and increases blood flow, and thus may improve erections. It has been shown to increase sexual arousal in rats, but has had mixed results in human studies. Side effects include a boost in blood pressure, abnormal heart rhythms, nausea, anxiety and sleeplessness. Because of safety concerns and the variability of the active ingredient, yohimbe should not be used.
Cocktails of ingredients: Many supplements contain a wide range of herbs traditionally used as aphrodisiacs—from ginkgo deer horn and horny goat weed (we kid you not) to damiana, maca, muira puama (meaning “potency wood”)—and an array of vitamins and minerals. But there is little or no solid scientific evidence for any of them. Manufacturers often say they have studies to support their claims, but these are almost always unpublished, involve rodents or isolated cells, or are of poor quality. For instance, they usually don’t test the products against a placebo.
A few years ago, the Food and Drug Administration (FDA) warned consumers not to use a variety of sex supplements because they were illegally laced with the active ingredients in drugs like Viagra. These compounds can interact with other medication and can be dangerous for people with certain conditions, and thus should be sold only by prescription and used under doctor supervision. The products were reformulated or taken off the market, but no one knows how safe the replacements are.
Bottom line: Supplements that are supposed to turn you into a tiger in bed are countless. Don’t fall for the claims. The side effects are largely unknown, especially when the ingredients are combined and taken by older men with existing medical conditions. In particular, experimenting with hormones, or anything that affects them, is always risky. If you have erectile dysfunction or other sexual problems, consult your doctor, not the salesperson at the health-food store or at a website.