You should always only use the fda-approved sterile applicators provided only should always be used to apply directly to the base of your upper eyelashes. The applicators have been specially designed and manufactured to meet fda standards, and ensure that the correct dose of is applied.you should only use the fda-approved sterile applicators provided and apply Latisse directly to the base of your upper eyelashes. The applicators have been specially designed and manufactured to meet fda standards, and ensure that the correct dose of is applied.