Used this product many times. It worked wonderfully for darker, longer and fuller lashes but, there was only one issue for me: It has no "curling" affect. Since my lashes are not naturally curled upright and straight, this is how they grew. Sure, I could use a curler, but, they do not stay due to my heavy eyelids.
I used it for a very long time, as I was somewhat happy with it. I ended up discontinuing use and get eyelash extensions. The cost per month is the same. One thing I was told: Only ONE drop of the solution was plenty to do 2 eyes. This makes the bottle last longer, - about 3 mos per bottle - however, this is not the directed use by the manufacturer. I saw stretching out my money was my best interest. I had the same results using one drop for both eyes, and it did help with "overage" on the bottom lashes and skin - as hair can begin to grow there if not careful. I have colored eyes (blue/green) and saw NO change in my iris color.