In 2001, Allergan developed a medicated eye drop called bimatoprost to treat glaucoma. By a stroke of serendipity, many of the patients noticed something happening to their eyelashes. Their eyelashes grew longer, fuller, and darker while on the medication. This unexpected side effect prompted Allergan to study bimatoprost for the use in eyelash hypotrichosis, which is the medical term for an inadequate amount of hair.

The study produced remarkable results. At week 16, patients had an average of 1.4 mm growth in length (25 percent increase) and a 106 percent increase in fullness and thickness. The results of the study resulted in Latisse® become the first and only FDA-approved treatment to lengthen, darken, and thicken eyelashes for people with insufficient lashes.