Chitin has a very large molecular weight and it is insoluble in everything, so it is very difficult to absorb. According to the person in charge of preparation, chitin was useless after eating. Nothing can be absorbed. Chitosan works better than chitin. It has tens of thousands of molecules. Although it is insoluble in water, it is soluble in dilute acid. It can dissolve 1% -5% in the stomach, and the remaining 99% -95% is excreted. So its effect is relatively poor. The molecular weight of it is below 5000, it's water solubility is also very good, and it's degree of polymerization is 2-15. Its absorption rate is above 80%, which works well.