Hyaluronic acid is a very safe and effective plastic material, which has been accepted by many beauty lovers with few allergic reactions. Therefore, experts suggest that if there are adverse reactions such as vomiting and rash after injection of hyaluronic acid, you should first see a doctor to determine whether it is an allergic reaction, because there are many reasons for allergic reactions. Relatively speaking, there are fewer reasons for allergic reaction of hyaluronic acid, because hyaluronic acid can be said to be a component of the human body itself.