The most common collagen in the market can be divided into two types, one is fish scale collagen and the other is fish skin collagen. For example, the former 10 collagen list, Tiffany's deep-sea cod collagen is recommended to everyone. So which is better, fish skin collagen or fish scale collagen? Obviously, fish skin collagen is good, otherwise it would not be recommended to everyone. Why is fish skin collagen good? Take Tiffany's collagen from deep-sea cod as an example. Cod skin originates from the 400-meter deep sea in gulf of alaska, which requires strict water quality and environment. Among them, collagen is rich, and its amino acid content, skin elasticity and thickness are much higher than those of other fish. Using modern technology to extract nutrients has high biological safety and is easy to be absorbed by our bodies. However, most of the fish scale collagen on the market is tilapia (tilapia is called "the best fish" by farmers). In China, fish and ducks are often kept in the same pond, which means that ducks are kept in the same place. The purpose of this is to feed fish with duck manure, resulting in the lack of necessary nutrients in the finished product. In order to increase production, farmers often feed tilapia with hormones. As we all know, fish scales are rich in calcium, and it is inevitable to go through the process of decalcification with industrial strong acid and alkali when extracting collagen. Strong acid and alkali are very corrosive, which will affect the normal function of respiratory tract and stomach, and excessive intake will cause toxic reaction. The more you say it, the more terrible it is, but that's the truth. Perhaps the price of fish scale collagen is low because of its low cost, which will attract some consumers. However, this kind of collagen not only has no brand guarantee, but is even harmful to our health. Hormones, strong acids and strong bases are very harmful to our health. So when we buy collagen powder, we should ask the store before buying it.