Compound Heparin Sodium Allantoin Gel is generally harmless when used as directed by your doctor, but may cause some adverse reactions such as dry mouth, digestive upset, and constipation. The main ingredient in Compound Heparin Sodium Allantoin Gel is allantoin, which is harmless to human skin in most cases. Some patients may experience dry mouth, gastrointestinal discomfort, constipation and so on. Only a very small number of patients may be allergic to allantoin, which may lead to rash, itching or even blisters, but this is rare. If any adverse reaction occurs, the drug should be stopped in time and go to the regular hospital for treatment. Compound Heparin Sodium Allantoin Gel can act directly on keratin, increase and promote the hydration capacity of the stratum corneum, reduce water loss, dissolve and soften keratin, promote cell regeneration to accelerate wound healing. Allantoin cream is a good post-traumatic skin healing agent and anti-ulcer medication, which is good for dry skin, skin ulcers and even gastrointestinal ulcers. Compound Heparin Sodium Allantoin Gel is a prescription drug and needs to be used under the advice of a doctor.