Wild yam comes from the root of the Dioscorea villos plant that grows in North and Central America, and has no relation whatsoever to the orange tuber vegetable that shares its name. The Aztecs and Mayans used wild yam to relieve aches and pains.
Wild yam contains a compound called diosgenin that has properties similar to hormones. In the last decade or so, wild yam cream has been marketed as a kind of natural progesterone-like substance that can counteract unpleasant menopausal and PMS (premenstrual syndrome) symptoms when applied topically to soft, fleshy areas of the body. Some claim it can act as a natural form of hormone replacement therapy. Despite anecdotal evidence, there is no scientific basis to support these claims as of yet.
That being said, the alkaloids in wild yam do have anti-inflammatory and muscle-relaxant properties, which may explain why it has a reputation for relieving menstrual symptoms. These alkaloids tend to calm the muscles primarily in the abdomen, and so some believe the herb may be beneficial for conditions like diverticulitis, irritable bowel syndrome and endometriosis. Steroidal saponins, another ingredient in wild yam, helps alleviate muscle pains and strains, and even inflammation associated with arthritis.
Wild yam is available in capsule, tablet, tincture, cream and tea form.