One for the bathroom shelf, one for the carry-on. A full-size fLASH Eyelash Serum stays home while the Lash Serum Mini travels, so once-daily never takes a day off. It's physician-formulated and ophthalmologist-tested for longer-looking lashes. Lash Serum: You may begin to see noticeable change in 2 to 4 weeks, with full results in 8 to 1