The medication finasteride has become popular among young men. But for those struggling to conceive, it could be the reason.
Soon after Will Stone and his wife, Brittany, got married in 2021, they started trying to have a baby. But early attempts didn’t pan out, and by the next year, they went in for testing.
Ms. Stone’s results came back normal. But Mr. Stone’s were more disappointing.
His sperm count was about 2 million per milliliter, far below the 10-million threshold his doctor told him was optimal for the couple to try intrauterine insemination, or I.U.I. He was referred to a urologist, who asked what medications he was taking.
When Mr. Stone, a data analyst in Austin, Texas, mentioned he took a 1 milligram dose of finasteride, a daily pill for hair loss, the urologist interrupted him.
“He told me to stop taking it immediately,” Mr. Stone, now 32, said.
Finasteride, sometimes sold as Propecia, is the most widely used prescription medicine for male-pattern baldness. Prescriptions have reportedly tripled in recent years alongside the rise of direct-to-consumer telehealth companies popular among young men.
For many, the medication comes with no issues and can provide newfound confidence, but it does carry side effects. Mr. Stone had known there was a small possibility of reduced libido and erectile dysfunction (between 1 and 2 percent), but he didn’t know that the drug might be linked to his fertility struggles.
Finasteride is prescribed at higher doses to treat enlarged prostates and has been known to mildly affect sperm counts. But Dr. James Kashanian, a urologist and the director of male sexual health at Weill Cornell Medicine, said the drug has also “significantly affected” some patients’ sperm quality, even at 1 milligram, the dose typically prescribed for hair loss.