this collagen is our most best selling product all over the world and it is suitable for women,old people,and all people which need to keep beauty or people who want to improve their skin prolbem ect.Before we produce this product,we invited dozens of experts in medicine,health science,nutrition,beauty skin care areas,according to the body&＃39;s own needs and repair functions,after repeated research,cost more than 30,769,000 USD and developed this most easily absorbed collagen powder.