NuSkin LASH & BROW SERUM has been in development for over 1 year with Clincally proven results of visibly longer and fuller looking lashes when you apply the serum 2x a day. No weird side effects! So many lash serums on the market have warnings for eyelid irritation and the possibility of affecting your eye color. EEK!! Ours does NOT contain this ingredient so we can use it worry free!