Before Viagra® was introduced to the market, discussions of men's sexual function hardly existed, shrouded in cultural taboo. However, as a result of Viagra's success, and the willingness to have these once taboo conversations, a nutraceutical category has evolved. In the brave new world of sexual function ingredients let caution and good sensibility be your guides through the outlandish claims and ridiculous hype, beyond which lie some ingredients that date back thousands of years and should be taken seriously.

When discussing sexual function ingredients such as maca and horny goat weed it is important to note that their use in sexual function is an American interpretation. These ingredients have been used by indigenous cultures throughout Asia and South America for a wide array of applications for several centuries. It's only been within the past four or five years that these ingredients have been picked up by the West and marketed specifically for sexual function applications.

Maca
Maca (Lepidium meyenii) is a cruciferous vegetable that is cultivated in a small region in the central Andes of Peru at altitudes from 11,000-15,000 feet. According to Herbal Secrets of the Rainforest by Leslie Taylor, the area where maca is found high in the Andes is an inhospitable region of intense sunlight, violent winds and below freezing weather. With its extreme temperatures and poor rocky soil, the area rates among the world's worst farmland, yet over the centuries maca learned to flourish under these conditions. Maca was domesticated about 2000 years ago by the Inca Indians and primitive culitvars of maca have been found in archaeological sites dating as far back as 1600 B.C.

Maca has been used medicinally for centuries to enhance fertility in humans and animals. According to Mark Miller, Ph.D., president, Rainforest Phytoceuticals, Delmar, NY, when Spanish explorer Francisco Pizarro conquered the Inca Empire he found that his horses and pigs would not reproduce in the high altitudes of the Andes. "He asked the natives how they got their llamas and alpacas to reproduce and they said they fed them maca," Dr. Miller explained. "Pizzaro did the same and was so impressed by the results that he exported roughly 900 tons back to Spain. You don't put 900 tons of maca on a ship in the 1500s and send it all the way back to Spain unless there's a reason for it."

Dr. Miller noted that maca is growing in world popularity due to its energizing effects, fertility enhancement and aphrodisiac qualities. Unlike Viagra, however, maca is not something that works instantaneously and it should be taken consistently over a period of time. Other traditional uses of maca include increasing energy, stamina and endurance in athletes, promoting mental clarity, treating male impotence and helping with menstrual irregularities and female hormone imbalances, including menopause and chronic fatigue syndrome. It is also sometimes used as an alternative to anabolic steroids by bodybuilders because it is rich in sterols.

In terms of nutritional value, dried maca root consists of 59% carbohydrates, 10% protein, 9% fiber and 2% lipids along with a large amount of essential amino acids and higher levels of iron and calcium than potatoes. "Maca is a very nutritional food product that has reasonable properties in a broad sense," Dr. Miller commented. "In terms of the sexual effects there is no evidence that maca raises sex hormones like testosterone, estrogen or progesterone. I think it's probably working through growth factors." Dr. Miller continued, "Although none of this is clinically proven, a possibility is that maca restores hormonal levels, growth factors or some other component, yet to be determined, that declines with aging," he said. "As we get older, function can decline as part of the normal aging process and maca restores aspects of youth by stimulating systems that are declining."

As for research, students in Peru have conducted many studies on animals whose diets were supplemented with 15-80 grams of maca a day over several weeks. In males, sperm count, motility and semen volume increased. According to Dr. Miller, "Whether this is comparable in humans is under investigation, but hormonal declines with age are similar to the effects of high altitudes on the body."

Currently in the U.S., maca is found mostly in capsule form. However Dr. Miller said his company is looking to incorporate it into functional foods such as protein bars and nutritional beverages so that it can be incorporated into an overall healthy lifestyle.

Horny Goat Weed
Horny goat weed (Epimeduim saggitatum) has recently been touted as a sexual enhancer in the U.S. although it has a long history of use in Traditional Chinese Medicine (TCM). Legend has it that the name came from a herder who noticed his flock of goats becoming suddenly sexually active after eating the plant.

Doug Buck, general manager, Renaissance Herbs, Chatsworth, CA, expanded on its history and recent popularity. "Epimedium is known to the Chinese as yinyanghuo-'herb that causes goats to copulate excessively.' Recent popular use of horny goat weed grew out of an increasing awareness of the need for dietary supplements to enhance sexual function in an aging generation of people," he explained. "Although horny goat weed was only popularized in the U.S. in the last five years, the use of epimedium in TCM is very old. A passage in the Shen Nong herbal book of remedies written approximately 1200 B.C., states that it was used to treat impotence and pains of the penis, to increase urination and to boost the qi, or life force."

Peter Hafermann, vice president marketing, Botanicals International, Long Beach, CA, talked about the hype surrounding horny goat weed. "Horny goat weed really caught peoples' eye because of the name on the bottle," he said. "There's a handful of horny goat weed products that quickly came in with a lot of marketing hype and we've seen most of them don't live up to the hype."

Botanicals International has recently been granted a patent covering the manufacturing process, composition of matter and the use of an epimedium purified extract. Rod Lenoble, technincal director, explained, "What we have done is taken the crude extract, purified it and isolated the components that we believe to be active." He added, "There's a lot of misconception and a lot of really bad products that claim to be true aphrodisiacs. The whole aphrodisiac category is very shaky. What we say with our product is that it helps to maintain normal function or helps with dysfunction."

According to Mr. Buck, how horny goat weed works to restore male sexual function is not well understood. "Based on animal studies multiple activities of the herb likely contribute to enhanced sexual function including peripheral circulatory, vasodilatory, androgenic and neurological activities," he explained, adding, "Clinical studies from China have so far been the most revealing."

In TCM horny goat weed is used to help treat chronic bronchitis, asthma, neurological and immunological inhibition, cardio-cerebral vascular disease, cerebral arteriosclerosis and coronary heart disease. Mr. Buck noted, "The extent to which the effect horny goat weed has on such conditions is unknown, however, it is widely believed that it may be addressing underlying conditions well known to contribute to such problems."

Despite the impressive profile of horny goat weed, there should be some caution concerning what is referred to in TCM as "yang excess," according to Brien Quirk, technical manager, Draco Natural Products, San Jose, CA. "Traditionally horny goat weed has been used to treat yang deficiency. As opposed to yin, which is associated with cold and calmness, yang is a quality of health that is hot and energetic," explained Mr. Quirk. "In Chinese medicine it is believed that impotence is caused by a kidney yang deficiency and that the kidneys are some how connected to the reproductive system." He continued, "The Chinese believe that when you have yang deficiency your sex drive is reduced, leading to a lower state of metabolism, so that you're more tired."

However, if someone displays symptoms of yang excess, taking horny goat weed can cause an imbalance between yin and yang, according to Mr. Quirk. "If an individual feels over stimulated or hot, irritable or has a condition like insomnia, then they shouldn't really be taking horny goat weed," he explained. "This is something that should be communicated to consumers. Horny goat weed is a yang tonic herb and there is supposed to be a very fine balance between yin and yang. Otherwise, it could potentially worsen certain conditions."

L-Arginine
L-Arginine is a well-known amino acid that has a long history of use in a variety of health applications. Don Blaine, vice president, Kyowa Hakko USA, Aliso Viejo, CA, commented on some of the key areas of use for the amino acid. "L-Arginine delivers a wide range or user benefits and has been a key ingredient for the nutraceutical industry for over a decade," he said. "Among its many product uses are weight loss, sports nutrition and more recently, sexual function enhancement."

Rainforest Phytoceuticals' Dr. Miller is the founding member of The Nitric Oxide Society and he explained L-Arginine's mode of action. "L-Arginine is the amino acid that's used to make nitric oxide, which is the chemical that is responsible for vasodilation (widening of the blood vessels), which is necessary to produce engorgement. You can't have an erection unless you have engorgement of the penis," he noted.

Dr. Miller explained further, "The idea behind adding extra L-Arginine to the body is that if you give more of the precursor then it will produce more output. Upon ingestion you will have a peak rise of L-Arginine levels in your blood and then it will decline. To get the desired effects L-Arginine should be taken about a half hour before engaging in sexual activity."

Along similar lines, Mr. Blaine added, "L-Arginine's role is as a precursor of nitric oxide, which enhances the flow of blood to the genital area. It is formulated in virtually all delivery systems including tablets, capsules and powders, and according to the desired effect and functionality, L-Arginine is used as both a stand-alone product and in combination with other ingredients."