LASH, BROW and HAIR should last 4-6 weeks when used as directed (longer for some users depending on application style): twice daily, morning and evening. Once you achieve your ideal look, you can reduce application to once per day — making the product will last much longer. When you want to accelerate the results again, just increase the frequency again to twice daily. Never use the LASH, BROW, or HAIR serum/treatment more than twice per day. The formula is maximized for potency at the recommended dose. More is not better.