Merck Says Its Hair Regrowth Pill Propecia Shows Promise in Trials

Balding men may soon be able to grow their hair back by popping a pill, the pharmaceutical firm Merck & Co. announced Sunday.

But a full head of hair may have a price men are unwilling to pay, the researchers said. Side effects include decreased libido and difficulty achieving erection.

Sixty-five percent of moderately balding men who took the drug Propecia daily for a year grew hair, compared with 37% of men who took a placebo, said Merck researcher Keith Kaufman, who presented the initial findings of his study at the American Academy of Dermatology convention.

The researchers, who tattooed a 1-inch circle on the scalps of the 1,550 men under age 45 in the study, found a 107-hair improvement among men taking Propecia, Kaufman said.

The drug, whose generic name is finasteride, suppresses the hormone that shrinks scalp hair follicles and reverses the balding process, Kaufman said.

“Finasteride is a unique product because it inhibits a key underlying process responsible for hair loss,” he said.

The drug is already on the market in a higher dosage under the name Proscar, a treatment for enlarged prostate glands. Merck applied in December for federal approval to market Propecia in 1 milligram pills. Approval processes normally take at least a year.

Propecia, named after alopecia, the medical term for baldness, may prove more effective than Rogaine, made by Pharmacia & Upjohn Inc., which has helped only a fraction of people tested in clinical studies, dermatologists said.

Unlike Rogaine, a lotion applied to the scalp, the more potent Propecia would be taken orally.