Ever since Viagra made its noisy public debut, dietary supplements companies have inundated the market with purported natural sex enhancers. Some of these products are nothing but hype, yet others contain time-tested ingredients that reportedly enhance libido and improve sexual function. The following five herbs have been used as such for many centuries. Each has been the subject of at least some scientific investigation, and each boasts a large number of satisfied users.
Horny goat weed (Epimedium)
This provocative name refers to a variety of plant species whose first recorded use in China dates back to 200 B.C. Its leaves and stems contain a variety of polysaccharides and the flavonoid icariin. These constituents are believed to be responsible for the plant's androgenic activity that increases both sperm production and blood testosterone in animals.
In traditional Chinese medicine, horny goat weed has been given to both sexes, but to different ends. In men, the herb reputedly promotes sperm production and sexual desire, and improves some cases of impotence. In women, the herb has primarily been used for fatigue and postmenopausal hypertension.
Maca (Lepidium meyenii)
Dubbed by the Miami Herald as "Peru's natural Viagra," maca's radish-like root has long been reputed to increase strength, energy, stamina, libido and sexual function. Today, as researchers and physicians explore both the phytochemistry and biological activity of the plant, historical claims made for maca appear to be true.
Maca root is a rich source of sterols, including sitosterol, campestrol, ergosterol, brassicasterol and ergostadienol. It is unknown exactly which of the root's constituents affect sexual desire and performance. Two groups of novel compounds, macamides and macaenes, appear especially active and are also being investigated.
In experiments conducted at the Chinese Academy of Preventive Medicine at the University of North Carolina at Chapel Hill, animals fed a standardized extract of maca demonstrated significantly increased energy and stamina, and exhibited an increase in sexual activity compared with animals not fed maca (Urology, April 2000).
Muirapuama (Ptychopetalum olacoides)
Few reputed health-enhancing plants are as popular or as widely consumed among the natives of the northern Amazon river basin as the bark of muirapuama. For centuries, this plant has been used to increase libido and improve sexual potency. The harvest and sale of muirapuama is big business throughout Brazil. As one Amazonian herbalist told me, "Muirapuama makes you sexually young again."
Although research on muirapuama is still modest, reports in scientific journals and at conferences have indicated that the herb does enhance sexual desire and performance. Chemists have identified a group of sterols, including beta-sitosterol, thought to be responsible for the herb's effects. In one French study using muirapuama, 51 percent of 262 men with erectile problems reported improvement, and 62 percent experienced an increase in libido.
Yohimbe (Pausinystalia yohimbe)
From the heart of the African continent comes the only reputed sex-enhancing plant whose primary active compound is classified as a drug. This tall evergreen forest tree's bark is rich in the alkaloid yohimbine. A central nervous system stimulant, yohimbine appears to work as a sexual catalyst in men by increasing blood flow to the penis. Men with penile circulatory problems typically get the best results with yohimbe. But men with psychological impotence also fare well using yohimbe bark products.
Not everyone finds taking yohimbe a comfortable experience. In some cases the bark can produce nervousness, insomnia, nausea and rapid heart rate. But for the those who tolerate yohimbe well, the concentrated bark extract imparts energy, a feeling of increased strength and increased sexual arousal.
Zallouh root (Ferulas harmonis)
Zallouh root, also known as shirsh zallouh, is a small shrub with thin leaves and tiny white or yellow flowers. The plant grows at altitudes between 6,000 and 10,000 feet around massive Mount Haramoun, which straddles the borders of Syria, Lebanon and Israel. The plant's root has been used as a sex enhancer since antiquity by men with erectile problems, and for men and women with low libido.
Until recently, zallouh was unavailable outside the region in which it grows. Its popularity and availability is spreading because of a growing body of scientific research. While many purported sex enhancers are the subjects of folklore alone, zallouh has been investigated extensively in clinical trials, and the results are impressive. The Lebanese government's interest in zallouh has led to a series of human studies involving more than 7,000 subjects.
One six-month study involved 315 men with a mean age of 55. Among the 159 who took either 500 or 1,000 mg of freeze-dried zallouh root, 80 percent experienced improvement. On a scale of 1 to 5, the men went from an average score of 1.26 (virtually no erection) to an average of 3.11 (a firm erection).
In the largest zallouh study, 4,274 patients, ages 18 to 87, participated. Of these, 2,722 took between 2 and 8 g of zallouh root daily in tea. At the end of the year, 2,199 patients taking zallouh had completed the study; the efficacy rate neared 86 percent for improved erectile function. These results are rather spectacular and show promise for large doses of zallouh taken over an extended period. Not all the studies were quite as impressive though. Results depend on the zallouh dosage and study duration. The lowest efficacy rates in clinical trials hovered around 60 percent, which is still quite good, compared with placebo efficacy of about 10 percent.
What is it about zallouh that so markedly improves erectile function? The root appears to contain ferulic acid, which dilates blood vessels and stimulates circulation. Those with hypertension, significant heart disease or diabetic neuropathy should not take zallouh root without physician approval. In some people, the root causes flushing and headaches as a result of the enhanced circulatory effects.
Chris Kilham is an author, medicine hunter and educator. His latest book Psyche Delicacies—Coffee, Chocolate, Chiles, Kava and Cannabis, and Why They're Good For You, was published by Rodale Press in November 2001.
Natural Foods Merchandiser volume XXII/number 11/p. 31