• Posted March 31, 2026

Intermittent Fasting Might Help Manage Female Hormone Imbalance, Trial Shows

Intermittent fasting might help manage symptoms from a hormonal condition that affects nearly 1 in 5 women, new clinical trial results say.

Weight loss associated with intermittent fasting helped lower testosterone levels in women with polycystic ovary syndrome (PCOS), researchers reported March 27 in the journal Nature Medicine.

These lowered levels could wind up improving PCOS symptoms over time, researchers said.

“This study and several other studies published by our lab and others show that intermittent fasting can actually improve female hormone levels, particularly in women with PCOS,” researcher Krista Varady, a professor of nutrition at the University of Illinois-Chicago, said in a news release.

PCOS occurs when women don’t create enough female hormones needed to ovulate, according to Johns Hopkins Medicine. As a result, the ovaries develop many small fluid-filled sacs called cysts, which produce male hormones like testosterone.

Higher levels of these male hormones cause problems like irregular periods, weight gain and infertility among women with PCOS, Johns Hopkins says.

“We’re looking for other ways of lowering testosterone levels in these women,” Varady said. “One way is through weight loss. If someone loses around 5% of their body weight, they can actually help lower testosterone levels and sidestep any kind of drug intervention.”

Intermittent fasting — restricting eating to a six-to-eight hour daily window — is one potential means of weight loss, but some critics have said the diet might instead disrupt female hormones.

“There’s a particular sentiment that intermittent fasting is really bad for women,” Varady said.

For the trial, researchers recruited 76 women with PCOS and assigned them to one of three groups.

One group adopted intermittent fasting; another tried to lose weight through calorie counting; and the third served as a control group that continued their usual diet.

Both fasting and calorie counting cut the women’s food intake by about 200 calories a day, and both groups lost an average 10 pounds during the six-month trial.

Both dieting groups also had a decrease in their testosterone levels, researchers said.

But only intermittent fasting reduced free androgen index, the ratio between testosterone and the protein that transports it through blood, researchers said. This is a marker of how much active testosterone is reaching a body’s tissues.

Intermittent fasting didn’t lessen PCOS symptoms like irregular periods, but researchers said those symptoms might improve with longer time on the diet.

About 80% of the women assigned to intermittent fasting said they planned to continue the eating pattern, Varady said.

More information

Johns Hopkins Medicine has more on polycystic ovary syndrome.

SOURCE: University of Illinois-Chicago, news release, March 27, 2026