DOCTORS TODAY prescribe a synthetic form of the female hormone progesterone for women with menstrual problems, osteoporosis, and menopausal symptoms. In spite of the known side effects and risks associated with taking synthetic progesterone, most doctors believe that the benefits generally outweigh the risks.

The risks, though, are not inconsequential. In addition to unpleasant side effects such as fluid retention and salt build-up, synthetic progesterone is known to cause some serious illnesses-blood clots and uterine and breast cancers.

Some women today are discovering, however, that they don't have to take synthetic progesterone. A natural-and safer-form of progesterone is readily available and is effective in relieving the symptoms for which synthetic progesterone is prescribed.

Marsha Sampson is a 40-year old woman who switched from synthetic to a natural progesterone. For her unpredictable menstrual cycle-which had included wild mood swings and irritability-- Sampson's physician prescribed the synthetic progesterone called Provera to help regulate her cycle. But the side effects were unacceptable to Sampson.

"Using Provera made me so nervous, my heart began to palpitate," she says. "At first I thought my doctor had prescribed speed."

Sampson consulted an acupuncturist, who recommended that she take the progesterone found in an extract of the wild yam plant. The acupuncturist gave her a cream containing the extract and told her to rub it into the soft parts of her body-on her belly and thighs and under her arms-right up to the time her period began.

"After using wild yam for three months, I was shocked," Sampson says. "I sailed right through my period. It was phenomenal. And my cycle became regular-every 30 days."

Wild yam's medicinal properties have actually been known for a long time by folk herbalist's and pharmaceutical manufacturers. Daniel Mowrey reported in The Scientific Validation of Herbal Medicine (Keats Publishing, 1986) that throughout the 18th and 19th centuries wild yam was used to treat menstrual cramps and problems related to childbirth.

In 1936, Japanese scientists discovered that a species of wild yam growing in the south of Mexico contained a chemical called diosgenin, which is remarkably similar to progesterone. For a number of years following this discovery, Mexican wild yam was a primary source for the production of progesterone and other hormones. Until recently, wild yam-not to be confused with the tuberous sweet potato yam-was the sole source of the diosgenin used in making contraceptive pills. According to herbalist Rosemary Gladstar in Herbal Healing for Women (Simon & Schuster, 1993), wild yam is "the most widely used herb in the world today." Over 200 million prescriptions that contain its derivatives are sold each year.

Although many physicians believe that there is no significant difference between synthetic and natural progesterones, others, such as New York City obstetrician Neils Lauersen, disagree. Lauersen says that some synthetic progesterones can have masculinizing effects on a woman, while others cause fluid retention. "Natural progesterone [from the wild yam], on the other hand, does not cause masculinization, and it is known to reduce sodium and fluid retention," says Lauersen, the author of PMS: Pre-menstrual Syndrome and You (Simon & Schuster, 1983).

John Lee, M.D., of Sebastopol, California, says that the reason synthetic progesterone causes side effects is because "it's not progesterone. The pharmaceutical companies alter the molecular structure so it no longer fits into the biochemical machinery of the body."

The progesterone taken from the wild yam, on the other hand, is nearly identical to what the body produces, Lee says. And the body easily converts it into the identical molecule. That is not the case with the synthetic compound.

By David Steinman