science of us

Viagra’s Other Life as a Female Fertility Aid

Photo: StockPhotosArt/Getty Images/iStockphoto

Since the FDA approved of Viagra 20 years ago today, the erectile-dysfunction drug has been used for plenty of other things. In 2000, for example, researchers at Johns Hopkins found it could relieve the symptoms of a digestive condition called gastroparesis in diabetics. It’s been used to help climbers in the Himalayas avoid altitude sickness, and documented as a treatment for pulmonary hypertension in pre-term babies. Some research suggests it may be an effective treatment against circulation disorders and even heart disease.

Of all the “off-label” uses that have emerged over the past two decades, though, one of the most successful — and most life-changing — is as a last resort for women struggling to have a viable pregnancy.

Viagra, the first drug prescribed to treat impotence, was created by accident when researchers were trying to develop a new blood-pressure medication. When they discovered its most common side effect was inducing an erection within 30 minutes or so, Pfizer saw an economic opportunity, patenting the drug in 1996 under its chemical name, Sildenafil. Two years later, on March 27, 1998 — a remarkably short time in the pharmaceutical world — the FDA approved Viagra for use in treating the condition they’d started to call “erectile dysfunction.”

It was a smash hit, yielding a billion dollars in profits in the first year alone. (It also completely changed the way drugs are marketed when former presidential candidate Bob Dole, then in his mid-’70s, appeared in a TV commercial for the “little blue pill.”) But while Viagra was being marketed to and used by men, fertility expert Geoffrey Sher saw the drug’s potential as a treatment for women struggling to get pregnant.

In 1989, Sher had published research examining the correlation between the thickness of a woman’s endometrium — the uterine lining — and the successful implantation of an embryo through IVF. As women age, the endometrium tends to thin, and the rate of IVF failure increases. So in 1998, when Sher read about Viagra, which works by increasing blood flow to the penis, he realized it should work similarly in women; increasing blood flow to the uterus meant thickening the uterine lining, creating a more hospitable environment for an embryo.

It worked. Sher had a compound pharmacy create a vaginal Viagra suppository, to deliver the maximum dose directly to the uterus. He began with four patients who’d struggled to conceive, and who’d had failed IVF cycles in the past. After eight to 11 days of Viagra suppositories administered four times daily, three of the women conceived.

“We moved on to a control study with more patients, and then published a second paper with a much larger number of women” in 2002, Sher says. In that study of 105 women, 45 percent of those treated with Viagra had a live birth after a single IVF cycle.

“It won’t work in everyone,” says Sher, who continues to use the treatment in his practice. For example, “it won’t work in women whose basal uterine lining has been destroyed by infection or endometritis … but when the thin uterine lining is a result of reduced blood flow, it is remarkably effective.”

“There are hundreds and hundreds of births that have occurred from this treatment over the years,” he says. “Is it the most groundbreaking advancement in fertility? No. But it’s been an important development for women who otherwise would not have had a baby.”

Viagra’s Other Life As a Female Fertility Aid