In “Sex and the City 2,” three members of the iconic quartet of die-hard female friends have fallen into an all too common rut of marriage, kids and career mayhem. But at 52, Samantha Jones (Kim Cattrall), the irrepressible publicist with a ravenous sexual appetite, has plunged into the scorching flames of menopause.

When the hormonal creams and pills that subdue her hot flashes are seized at the airport, Samantha makes due by ingesting loads of yams and using the mashed vegetable as a facial mask.  

Although wild yams play a role in the alleviation of menopausal symptoms, the route that Samantha takes is not the way to go, says Holly Lucille, a naturopathic doctor in private practice in Los Angeles, and the author of Creating and Maintaining Balance: A Woman’s Guide to Safe, Natural Hormone Health.  

The wild yam-progesterone connection

Over the last five years, says Lucille, an increasing number of her patients transitioning through perimenopause and menopause have sought out natural hormone remedies, such as transdermal creams containing progesterone. Research has shown that progesterone may contribute to alleviating hot flashes. But, she says, not all creams are created equal.
Much of the confusion stems from the misunderstood relationship between wild yams and progesterone.

USP progesterone should be the key ingredient in transdermal progesterone creams, says Lucille, who’s also a registered nurse. (USP stands for United States Pharmacopeia, which sets standards for prescription and over-the-counter medicines.)

USP progesterone is created in a laboratory. The raw material, says Lucille, is diosgenin extract, a phytoestrogenic compound which comes from the wild yam. Diosgenin cannot be converted by the body into progesterone. So the transformation needs to happen in a lab, she says.  

The right progesterone dose

In treating her patients, Lucille finds that, to be effective in symptom relief, a progesterone cream should contain a minimum of 400 mg of USP progesterone for each ounce of cream. A two-ounce tube should ideally contain 800 mg of USP progesterone. “A lesser amount will not be effective for symptom relief,” she says.

When the label on a tube of so-called progesterone cream says that the contents are just wild yams or diosgenin, the product won’t alleviate symptoms because it contains no progesterone, says Lucille, underscoring that the body can’t turn these ingredients into the hormone the body needs. Unfortunately, she says, many women see the word “natural” on the package and buy the product, without checking out how much USP progesterone the product actually contains.  
Some products do contain both USP progesterone and wild yam or diosgenin, says Lucille, but in these cases you might be getting less USP progesterone than you think. Some products contain as little as 2 mg of progesterone in one ounce of cream, she says.  

Getting your doctor on board

Lucille advises women who see no decrease in their symptoms – including hot flashes – after using progesterone cream to see a medical professional who’s knowledgeable about progesterone and who can customize the daily dose of the cream. Another option is customizing hormones with a prescription that can be filled at a compounding pharmacy.  

As for the yams, they’re a good source of vitamin C, potassium and manganese – not progesterone – and taste great baked, served with olive oil drizzled on top.

Coeli Carr is a health and fitness writer in New York City.