Enzymes are proteins composed of varying amino acids that catalyze a range of chemical reactions within the body.  Enzymes used in dietary supplements can be derived from fungal, plant or animal sources, with the majority coming from fungus. Their most popular use, and that with the greatest clinical data, is to support digestive health. Bromelain (protease) helps break down proteins, amylase digests starch, cellulase digests plant cellulose, lipase digests fats, lactase digests lactose found in dairy products, and phytase digests grains and legumes.  Many enzymatic digestive products contain a mixture of these enzymes.

Enzyme products also have applications in joint health.  One study involving the use of protein-dissolving enzymes (including bromelain, papain, trypsin and chimotrypsin) for treatment of osteoarthritis and rheumatic conditions found that enzymes were as effective as N-SAIDs in treating joint pain. Enzymes also have analgesic and anti-inflammatory properties useful in injury recovery as well as chronic joint issues.