Doudoufei and Bizhigao are both calcium hydrogen phosphate particles of lysine, which are products of promoting normal growth and development. Lysine and calcium hydrogen phosphate are both essential components in the process of human growth, but they are easy to be missing. If I have to compare similar products, I personally prefer Doudoufei in Aodong, Jilin. After all, it is a big brand, the quality is very popular in the industry, but the price is not cheap. I hope it helps you.