Women with polycystic ovary syndrome (PCOS) may now have a better therapy for their condition. Resveratrol, an anti-inflammatory compound found in grapes (and wine), berries and nuts, is the first natural compound that has been shown in a clinical study of PCOS to reduce the higher-than-normal levels of testosterone that are the hallmark characteristic of this very common but hard-to-treat endocrine disorder that affects one out of 10 American women of childbearing age. (Although we think of testosterone as a man’s hormone, women also need it but in much smaller quantities.)

If you have PCOS or know someone who does, you’ll want to keep reading…


Symptoms of PCOS, such as irregular and painful periods, excess facial and body hair and weight gain, are distressing enough on their own. For women who want to have children in the future, the effects are particularly disturbing—the increased testosterone levels may interfere with normal ovulation and thus reduce the ability to become pregnant. There are serious long-term health concerns, too. Women with PCOS are at higher risk for diabetes, stroke and heart disease.

While PCOS is a chronic condition that is not well-understood and can’t be cured, symptoms can be somewhat managed with birth control pills, which can help reduce testosterone levels, and the drug metformin, which can improve insulin sensitivity (reducing associated diabetes risk).

Oral contraceptives, though, come with an increased risk for blood clots—exactly what women with PCOS don’t need because they already face a 50% higher risk for blood clots than women without PCOS. Indeed, women with PCOS who take oral contraceptives are twice as likely to develop blood clots compared with women who don’t take the pills.

It’s clear that there is a pressing need for a safer treatment method. Resveratrol could be it.


First, a little background: Researchers at Poznan University of Medical Sciences in Poland and University of California-San Diego had already determined that exposing certain ovarian cells that produce testosterone to resveratrol reduces the cells’ ability to produce the hormone—without affecting production of progesterone, an important hormone needed to keep the uterine lining healthy. But that was a test-tube study using cells from rats.

For the new study, the first ever clinical trial of its kind, the researchers randomly assigned 34 women with PCOS to receive either resveratrol or placebo pills for three months. At the start and end of the study, all of the women had tests to measure body mass index, insulin resistance, levels of various hormones and cholesterol. Because some of these values change naturally throughout the month, testing was done at the same time for each woman’s cycle.

Results: After three months, the resveratrol group showed a 23% reduction in testosterone levels…a 22% reduction in a marker for DHEA, the precursor compound for both testosterone and estrogen…and a 66% increase in insulin sensitivity (a good thing) from their baseline levels. The women in the placebo group did not see any improvements in these measurements. Cholesterol levels stayed level in the test group but rose for those taking placebos.

Even better: The drop in testosterone was greater than the decline seen after three months of treatment with birth control or with metformin.


To better understand the research, we spoke with Andrew L. Rubman, ND, Bottom Line’s contributing medical editor and a naturopathic physician. He found the study promising—with caveats. “For women with PCOS whose symptoms are being treated conventionally with hormones and/or metformin, resveratrol may be a better alternative—in the short term,” said Dr. Rubman. Why the caveat? It’s a small study, for one, and the first of its kind to study resveratrol’s effects on PCOS. It’s also a short-term study, so it doesn’t address whether taking resveratrol long-term might affect estrogen production, which could happen from the decrease in DHEA. Nor do we know whether there are long-term effects on adrenal steroids, such as cortisol, which are closely linked to sexual steroids, adds Dr. Rubman.

With those caveats, he certainly thinks resveratrol is a supplement women with PCOS should discuss with their health-care providers, who can monitor hormonal and metabolic responses over time. It can be part of a complementary medicine approach to PCOS, which involves diet, exercise and weight loss as well as other supplements—including cinnamon, flaxseed, spearmint tea, B multivitamins and glucomannan, a fiber supplement that helps with appetite and blood sugar control. (While these are each beneficial in different ways for women with PCOS, none of them directly affects testosterone levels, as resveratrol does.) Stress control makes a difference, and acupuncture may also help.

Dr. Rubman pointed out that although PCOS is a chronic condition, symptoms may not always be bothersome, so women may be able to wean themselves off treatment. “Women with PCOS may not need treatment all the time, and the dose of resveratrol can potentially be reduced over time,“ he explained. “The most important time to take resveratrol is a few days before, and during, ovulation, when follicle-stimulating hormone (FSH) surges,” says Dr. Rubman. “It is regarded as beneficial throughout the cycle as well.”


The dosage of resveratrol used in the study was 1,500 milligrams (mg) per day, about three times the normal dose in an over-the-counter preparation. Although 1,500 mg is a potent dose, most women should be just fine taking it, said Dr. Rubman, although some may notice bowel irritability, which should go away in a few days.

For women who want to give resveratrol a try, Dr. Rubman recommends Nutrigenomic Super BerryWhole Food POWder manufactured by Eclectic Institute. Its resveratrol is derived directly from berries rather than synthesized, and the supplement contains other healthful compounds as well. (Note: While berries are very healthful, you can’t eat enough to get anywhere near the dose of resveratrol studied.) Bonus: Resveratrol may also help protect against osteoporosis.