Your favorite beer might be giving you man boobs

It might seem manly to drink beer, but a chemical found in hops might be the cause of some very feminine attributes.

Hops, which gives beer its flavor, are female flowers of the hop plant and contain high levels of phytoestrogen—a plant estrogen.

According to research conducted by acclaimed herbalist and author Stephen Harrod Buhner, hops can also contribute to breast development in men and to a condition called “brewer’s droop”—or impotence brought on by heavy drinking.

“[From] long-term exposure to the estrogenic properties of hops, [they] eventually have difficulty sustaining erection,” Buhner told Vice News.

In his book, Sacred and Herbal Healing Beers, Buhner says that hops have long been used in herbal medicine to help treat things like insomnia and endometriosis, and ease symptoms of menopause.

Men who drink lot of hoppy beer, like a strong India Pale Ale, may see some unwanted effects, like man boobs, premature aging, sluggishness, tooth decay, hair loss and a beer belly.

Severe drinking can also damage the liver, which undermines the organ’s ability to metabolize hormones. An inefficient liver will convert male androgens into the estrogens, resulting in the dreaded man-boobs, or “moobs,” Dr. Robert D. Galiano, a plastic surgeon at Northwestern Memorial Hospital, told Muscle & Fitness.

But America has developed a taste for hoppy beer.

IPA is the best-selling craft-beer category. According to IRI, a market research firm from Chicago, sales of IPAs in the U.S. surged 50 per cent last year and accounted for a quarter of all craft beer sales. Craft brewers typically use four to five times more hops than mass-produced beer, and as a result, hops are in short supply.

But, if having a beer belly and beer chest don’t appeal, try cutting back on your favorite hoppy brew.