Gentle OPTIPRO H.A. is the improved version of OPTIPRO H.A, with the level being optimized. The Gentle OPTIPRO H.A. in our NAN SUPREMEPRO H.A. is our exclusive, optimized protein blend obtained through a special treatment that breaks down the milk protein (partially hydrolyzed protein), making it easy to digest and hypoallergenic (reducing the risk of allergies). Do note that not all partially hydrolyzed protein are the same.