Review (3/5): but I did note that my mascara was going on better - making my lashes appear longer
I used this product for 8 weeks. The packaging indicated I would see a difference as early as 2 weeks, with its full effects seen in 6 weeks. At two weeks, I didn't '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 8 weeks of use: my eye lashes, without mascara, did not appear longer, but with the assistance of mascara and the serum, the lashes appeared a little longer at the outer edges of the eye (not the lashes of the inner eye).
Note: 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.