This retinol serum has a nice ingredient list, a good percentage of retinol (enough to give the results) , it's not too expensive and didn´t irritate my skin or cause acne. I only wish it was a bit more hydrating but I like to use a moisturizer after my retinol anyway so no problem with that. Alpha-H is a really nice brand so I definitely trust the brand and their formulation and I plan to continue to use this for a long time.