first i would like to thank you a lot for the answer and i just want make sure if that will be safe 100% to use on upper eyelashes line only, i will use it only with a little amount on upper eyelash, but i am afraid if there are any side effects may appear on the long run of the usage, especially when i knew that i have to use it forever because if i stopped it my eyelashes will turn back to its old shape, also I’m afraid if that may cause any Cancers on the long run, tell me use it or don’t plz