(MONEY Magazine) – In 1984, the Upjohn Co. revealed that it had a blood pressure medicine called minoxidil that, in effect, might do for baldness what some doctors now think Retin-A may do for wrinkles. Minoxidil, it said, had been shown to grow new hair on the heads of two out of three balding men. Trouble was, these early reports got blown out of proportion, aided in part by Upjohn's publicity efforts, which, like Ortho's wrinkle cream promotions, earned an FDA reprimand. In Upjohn's case, the FDA sent a letter chiding the company for issuing a press release on April 29, 1986 that regulators determined ''exaggerates the efficacy of the topical use of minoxidil.'' Upjohn denied the allegation. But it could not deny the impact that the press release had on company stock, which rose more than 9% to $174.25 in 48 hours. Upjohn's minoxidil sales had climbed from $14 million in 1984 to $33 million in 1986. Since then, however, U.S. sales have failed to grow despite the FDA's decision last summer to let Upjohn market minoxidil (see above) as the prescription hair-grower Rogaine. One reason for the drab sales: as it turns out, Rogaine works best for a minority of younger men with thinning hair and does only a little for receding hairlines. -- M.G.