4 years of use before I discontinued use. Prevented my hair from falling out some.This product has been recommended by my hairdresser, but I am not sure if it is effective. This si the first time that I buy this kind of recovery hair products.GoodIt's best used after buzzing or shaving your head. Otherwise, it pulls out the hairs you already have in the spots you apply the patch.Ok product, but really hasn't done anything.....I have been using this product along with the shampoo for the past two months and have noticed zero improvement. Next time I will get the ingredients before buying because this really doesn't do anythingworks well. use them in combination with the shampoo and the foam and it works well. awesome product for sure.Didn't work for me.. Thinned my hair out more, better luck for the next guy!I love it