Latisse is an FDA-approved topical treatment used to stimulate the growth of eyelashes. Latisse is typically applied to the base of the upper eyelashes once per day. Most users begin to see results within four to eight weeks, with the most dramatic results appearing between weeks 12 and 16. If you stop using Latisse, your eyelashes will eventually return to their original state. In some cases, Latisse may cause permanent changes to eye color.