Rogaine: the blood pressure drug that grew hair instead of fixing hearts

In the late 1950s, the Upjohn Company began developing a compound to treat ulcers. The compound did not cure ulcers, but it proved to be a powerful vasodilator — a drug that widens blood vessels. Upjohn synthesized over 200 variations, one of which became minoxidil (internal code U-10858). The FDA approved oral minoxidil tablets under the brand name Loniten for treating high blood pressure in 1979.

But the hair growth discovery came earlier. When Upjohn sent minoxidil to the University of Colorado for hypertension trials, Dr. Charles Chidsey noticed something unexpected: patients were growing hair. Puzzled, Chidsey consulted Dr. Guinter Kahn, a dermatology resident at the University of Miami who had independently observed the same effect. Kahn and his colleague Paul Grant obtained minoxidil and experimented with a topical solution. Neither Upjohn nor Chidsey had planned to study hair growth — the discovery was a side effect of a blood pressure trial.

Both parties filed competing patents, leading to a decade-long legal dispute resolved in 1986 with a consolidated patent and royalties to both Kahn and Grant. Meanwhile, physicians were already prescribing Loniten off-label for balding. In August 1988, the FDA approved topical minoxidil for treating baldness in men under the brand name Rogaine (the FDA rejected Upjohn's first choice, 'Regain,' as misleading). The agency found that 39% of men studied had moderate to dense hair growth. In 1991, Upjohn made Rogaine available for women.

Rogaine became a blockbuster. In February 1996, the FDA approved over-the-counter sale and generic formulations. Upjohn responded by cutting prices in half and releasing a 5% prescription formula in 1997, approved for nonprescription sale in 1998. By 2006, the 5% aerosol foam formula was approved. The hair growth market that began as a side effect in a blood pressure trial is now worth billions of dollars annually.