A preparation of leaf pulp from the parenchymal tissue of the plant aloe vera (Asphodelaceae).
Aloe vera gel contains carbohydrate polymers, such as glucomannans or pectic acid, and various vitamins and essential amino acids, as well as other organic and inorganic compounds.
This agent has been used internally or externally as a treatment for sunburn, skin problems, insect bites, ulcers, arthritis, and constipation. It has also been used as an immune system enhancer.

National Cancer Institute. NCI Drug Dictionary. Internet. September 15, 2009.