but i did note that my mascara was going on better making my lashes appear longer [SEP] i used this product for weeks the packaging indicated i would see a difference as early as weeks with its full effects seen in weeks at two weeks i did not see a difference but i did note that my mascara was going on better making my lashes appear longer this continued to be the case even after weeks of use the serum can only be used on the upper eyelid lashes not on the lower lashes also if too much serum is applied to the upper lid it can seep into the eye and cause burning