Latisse is an FDA-approved treatment to grow eyelashes for people with inadequate or not enough lashes. Latisse is typically applied to the base of the upper eyelashes once per day. Most users begin to see results within 4 to 8 weeks, including length, thickness, and darkening of the lashes, 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.