The side effects and hazards of enzymes are mainly as follows: 1. Allergic reactions. After a small number of people consume it, it will cause rash, itching, sweating, abdominal pain and other adverse reactions, so people who are allergic to enzymes should be prohibited. 2. Currently, many enzymes on the market are homemade and do not have standard formulas, and the sugar content is excessive, so diabetic patients should use them with caution. 3. Many homemade enzymes are not hygienic and the production process is prone to germs, which is a hidden danger to health. So try to buy enzymes from big brands and companies with good reputation. The fermentation process of homemade enzymes produces some harmful substances, such as methanol, which can cause methanol poisoning when taken in large quantities for a long time. Especially for fruit enzymes, the fermentation process is relatively complicated, and many manufacturers use poor quality fruits, which can easily produce mold after fermentation and cause serious harm to human health.