Scientists gave the drug the lackluster name of minoxidil, and began testing its use in treating hypertension. As is the case with many new drugs, minoxidil had side effects--in particular, one most interesting side effect. On some people, it grew hair.

"The problem has been that there is no way to tell who will grow hair, what kind of hair will appear, or where on the body the additional hair will grow," said a spokesman for the Upjohn Co., developer of minoxidil.

But the scientists wondered if they might not have stumbled across a holy grail of modern cosmetic medicine: a drug that retards baldness.

To find out, Upjohn is sponsoring a $3 million research project at the Washington Hospital Center and 20 other sites around the country. The hospital center's research is designed to determine whether minoxidil will promote the growth of new hair in men and women who have "male pattern baldness," characterized by a clean pate with a normal growth of hair above the ears and at the back of the head.

Dr. Thomas Nigra, chairman of the department of dermatology at the center, estimated yesterday that about one out of seven persons in the general population of men and women suffers from baldness. He said that there are about 50 percent more men with the condition than women.

"Baldness has been around since the beginning of written language. The Egyptians recorded instances of it," Nigra said yesterday. "Science has not found any treatment, either by direct application or by mouth, that effectively treats baldness."

Nigra said that the hospital center is looking for 100 volunteers who have male pattern baldness and want to do something about it. The volunteers, who will be studied for 12 months, will not be paid, he said.

The ideal participants, he said, are bald persons with a reasonable crop of thin hairs on top of their heads. The participants will be asked to massage an application of liquid minoxidil into their scalps twice a day. Researchers want to see whether the thin hairs will spring to life when the treatments are applied.

The liquid minoxidil that will be used in the research costs Upjohn about $100 per ounce, Nigra said. Once treatments begin, they must continue or the growing hair could revert to its previous lifeless state, he added.

Peter Rosenberg, 40, who said that he has suffered from baldness since his teens, was one of the first to sign up at the hospital center for the test, which is scheduled to begin April 1. Rosenberg, an Arlington engineer and patent attorney, appeared at a hospital center press conference yesterday as a model test subject.

"I have searched in vain for 25 years for a cure for my baldness, and I hope this is it," Rosenberg said.