When glaucoma sufferers started using the eye-drop drug Lumigan eight years ago, who knew there’d be fringe benefits: longer, lusher, darker eyelashes. Eventually, Allergan, the makers of the drug, sped it into clinical trials (this time for hypotrichosis, aka underdeveloped eyelashes), repackaged it, gave it a girly name (Latisse), and marketed it for its lash-boosting magic. Now, with FDA backing, it’s headed to a pharmacy near you.

It isn’t the first time a serious disease-fighting treatment has been repurposed for its surprise payoffs. Some of today’s most famous drugs were accidental discoveries: Cosmetic Botox (also made by Allergan) was first used by ophthalmologists to suppress eyelid spasms; Minoxidil debuted as a blood-pressure remedy; and Viagra was an enthusiastic by-product of a hypertension cure.

But instead of helping you recover your original smooth-skinned, fully maned self (as with Botox and Minoxidil), Latisse actually changes what your genes had programmed for you before birth, as if something had been clinically amiss all along. As Victoria Pitts-Taylor, Ph.D., a sociologist at City University of New York, puts it: “The line between medicine and cosmetics is blurring. Having a drug in your makeup bag next to your tweezers and lipstick is the new norm.”

When glaucoma sufferers started using the eye-drop drug Lumigan eight years ago, who knew there’d be fringe benefits: longer, lusher, darker eyelashes. Eventually, Allergan, the makers of the drug, sped it into clinical trials (this time for hypotrichosis, aka underdeveloped eyelashes), repackaged it, gave it a girly name (Latisse), and marketed it for its lash-boosting magic. Now, with FDA backing, it’s headed to a pharmacy near you.

It isn’t the first time a serious disease-fighting treatment has been repurposed for its surprise payoffs. Some of today’s most famous drugs were accidental discoveries: Cosmetic Botox (also made by Allergan) was first used by ophthalmologists to suppress eyelid spasms; Minoxidil debuted as a blood-pressure remedy; and Viagra was an enthusiastic by-product of a hypertension cure.

But instead of helping you recover your original smooth-skinned, fully maned self (as with Botox and Minoxidil), Latisse actually changes what your genes had programmed for you before birth, as if something had been clinically amiss all along. As Victoria Pitts-Taylor, Ph.D., a sociologist at City University of New York, puts it: “The line between medicine and cosmetics is blurring. Having a drug in your makeup bag next to your tweezers and lipstick is the new norm.”