Herbal Viagra: Separating Fact from Fiction
Love in the air this Valentine’s Day! Herbs can help you set the mood, but not all are safe. I break down fact versus fiction on popular herbal sexual stimulants.
You may have seen them on gas station shelves or advertised online for mail order: fancy packaging featuring “Herbal Viagra” on the label. Some are marketed as “all natural” or even “organic,” and as a consumer, it is easy to be fooled into thinking that this product is natural and safe. Why not take it to spice up your sex life?
Herbal Viagra
Fiction: Herbal Viagra products are 100% all-natural and safe.
Fact: The U.S. Food and Drug Administration has issued public notifications on several fraudulent male sexual stimulants marketed as dietary supplements. Take for example the 2020 FDA notification on a product marketed as “Herb Viagra”. Chemical evaluation revealed that the product contained sildenafil, a synthetic pharmaceutical molecule that is the active ingredient in Viagra, the FDA-approved prescription drug for erectile dysfunction.
Erectile dysfunction, or ED, is a common sexual problem for men, affecting 30 million Americans. Products containing prescription medication for ED can be very dangerous, especially for people with diabetes, high blood pressures, heart disease, or who take prescription nitrates. There is no way of knowing what dose of active agent these fraudulent products may contain. Overdose on sildenafil can result in symptoms of vision and hearing problems, fainting, low blood pressure, upset stomach, and chest pain.
What this means for you
Avoid these products, especially any that promise quick (30-40 minute) results as they likely contain sildenafil or tadalafil (the active ingredient in Cialis). This is not a safe way to access these prescription medications. See your doctor to determine if a prescription medication is right for you.
What can nature offer?
Fiction: There are no sexual stimulants from nature.
Fact: Some botanicals have shown promise in scientific and clinical studies. However, there is still a significant amount of uncertainty surrounding their effectiveness compared to other treatments for erectile dysfunction (ED) and female sexual dysfunction (FSD).
Let’s examine the evidence behind four popular botanicals used for this purpose.
Papaverine from the opium poppy
Papaverine is a natural molecule found in the opium poppy (scientific name: Papaver somniferum). Papaverine is a prescription drug with an off-label use for achieving an erection in men with certain types of ED. Papaverine is injected directly into the penis, where it acts as a vasodilator and increases blood flow to the site. The drug is quick-acting, taking effect in 10 minutes. Its use is limited today due to risk of scarring and priapism (unwanted, persistent erection).
Tribulus terrestris
Tribulus terrestris is used as an aphrodisiac in Ayurvedic medicine. Studies in male humans and animals have demonstrated improved libido and sperm production, as well as increases in testosterone production. The potential role of the plant in treating male infertility is under debate and rigorously controlled clinical trials are needed.
You may be wondering, What about women? Female sexual dysfunction (FSD) is a common disorder divided into four categories:
hypoactive sexual desire disorder
sexual arousal disorder
orgasmic disorder
sexual pain disorder
Many women turn to medicinal plants, like T. terrestris, to manage their condition. One of the active compounds found in the plant is the natural molecule protodioscin, which can affect androgen production and influence hormonal activity. A systematic review of five randomized controlled clinical trials concluded that after 1 to 3 months of T. terrestris, both premenopausal and menopausal women experienced significant improvements in their sexual function scores. However, the certainty of the evidence is low due to limitations in the design of these trials. More clinical trials are needed.
Yohimbine from Yohimbe
Source of bark image: NIH/Steven Foster.
Pausinystalia yohimbe is a tree native to West Africa, where it has a tradition of use in folk medicine as an aphrodisiac. While banned in many other countries, extracts derived from the bark of this plant have been used in the US in dietary supplements to treat ED. Harvesting the bark kills the tree, and yet hundreds of tons of bark are shipped annually, often wild-harvested illegally.
Yohimbine is a pure molecule isolated from the bark, whereas Yohimbe refers to the bark or bark extract and is composed of many different plant molecules. Yes, it can be a bit of a tongue twister!
The yohimbine molecule acts on receptors associated with libido and erection. A pharmaceutical version of this, yohimbine hydrochloride, is available as a prescription drug. In the US, yohimbine is found in many dietary supplement products, though alarmingly, one study found that the actual amounts of yohimbine in many supplement brands are either lacking or inaccurately labeled, raising concerns over the potential to take dangerously high doses.
Danger! Yohimbine poisoning has been reported with links to possible fatal outcomes. More rigorous controls on dosing in supplements and studies on the safety of this ingredient are needed.
So, does it work? A 2021 systematic review and meta-analysis examining clinical trials in which yohimbine was compared to placebo or no treatment, found that yohimbine only improved erectile function in ED patients if combined with other supplements, having limited activity on its own. Other studies have concluded that yohimbine has limited efficacy in treating sexual dysfunction and has significant adverse effects such as panic attacks, headaches, and high blood pressure.
Ginseng
In Traditional Chinese Medicine, ginseng has long been considered a panacea—or cure-all. This plant also has a rich history of use as a sexual stimulant and is thought to work by enhancing nitric oxide synthesis in the corpora cavernosa (the erectile tissue that forms most of the penis and clitoris).
A comprehensive review of nine clinical trials with mild to moderate ED examined the efficacy of ginseng supplementation compared to placebo. The review concluded that ginseng may improve men’s self-reported ability to engage in intercourse, but the low-certainty nature of the evidence raises concerns that ginseng may have only trivial effects compared to placebo. More rigorously controlled studies are needed.
A note on safety: If you ever experience an adverse event from medical products, including herbal products, you can report this to the FDA’s MedWatch Online Voluntary Reporting Form. If you experience a medical emergency, seek immediate medical care.
What do we know (and not know)?
There are many herbs rumored to enhance libido and treat male and female sexual dysfunction. These medical traditions are found in cultures across the globe. For most of these herbs, we still haven’t applied the necessary scientific tools to understand:
if they work
if they’re safe
how they work
which molecules are responsible
One thing is certain, though: molecules of incredible importance to reproductive health have been found in plants and developed into medicines used worldwide. One need only look to the story of the Mexican Yam and advances experienced in the development of birth control pills in the past century for inspiration. I’ll be sharing that story and more in future newsletters.
For now, I wish you all a very happy Valentine’s Day!
Yours in health, Dr. Quave
Nature’s Pharmacy is written by Cassandra L. Quave, Ph.D.—a disabled writer, speaker, podcast host, professor, wife, mother, explorer, and ethnobotanist. Dr. Quave is Associate Professor of Dermatology and Human Health at Emory University School of Medicine. She has written about her work as a scientist in The Plant Hunter: A Scientist’s Quest for Nature’s Next Medicines (Viking/Penguin 2021). During the day, she teaches college courses and leads a large group of talented research scientists studying medicinal plants in the search for new life-saving drugs from nature. In her spare time she hosts the Foodie Pharmacology podcast and writes this newsletter. Her main goal is to share the incredible science behind the medicines found in nature. This newsletter is only possible through the generous support of fellow Nature’s Pharmacy community members. To support this effort and join the community, subscribe below.