Yes — several studies and statistics from the FDA show that by week 16 of use, a majority of patients saw marked improvement in their lashes. In the case of the FDA’s data, 78% of patients using Latisse saw improvements at 16 weeks versus 18% of those using only the drug vehicle (the other parts of the drug, minus the active ingredient).United States Food & Drug Administration. (2012). Latisse (bimatoprost ophthalmic) solution label. FDA.