Our natural formula has been used exclusively by our salon customers until now... and is fast, effective, and will not interfere with eyelash extensions as it is oil-free. Shigeru® Lash Serum will help you grow longer, thicker lashes with noticeable results averaging under 30 days. For best results, always start with a 60 day supply (2 bottles). Although most people see amazing results in under 30 days, effectiveness will depend on your natural eyelash shed cycle period)