The properties of Capsaicin
Capsaicin is an active component of chili peppers, which are plants belonging to the genus Capsicum. Capsaicin and several related compounds are called capsaicinoids (dihydrocapsaicin, nordihydrocapsaicin, homocapsaicin and homodihydrocapsaicin) and are produced as secondary metabolites by chili peppers, probably as deterrents against certain mammals and fungi. Pure capsaicin is a hydrophobic, colorless, highly pungent, crystalline to waxy solid compound.
Capsaicin stimulates the circulation and alters temperature regulation; topically desensitizes nerve endings and acts as a local analgesic.
Acute capsaicin treatment causes release of substance desensitization of the respiratory tract mucosa to a variety of lung irritants.