The first time I tried the patch, it didn’t work. It didn’t fill at all. The second try, I really tried to make sure there wasn’t any user error, and it filled a little bit, but not entirely. The results were interesting, and I like the idea of checking out hydration this way. They seem very expensive, and I would hate to ruin a patch I paid for if it didn’t work next time. Interesting product, but I would not recommend