Two hours is required for a full application, and the results are immediate and spectacular. You will enjoy longer and thicker eyelashes at last! Take note however that your natural lashes have a mean lifespan of 60 days as new lashes are always coming out. That’s why touch-ups are recommended every 3 weeks on average to maintain the fullness of your eyelashes. A fill lasts about 60 minutes and is meant to replace the natural lashes you have lost.