The capsaicin family is a high content of active ingredients in peppers,and has pharmacological effects in anti-oxidation,anti-tumor,anti-gastrointestinal ulcer,weight loss and analgesia. Studies have shown that the pharmacological activity of capsaicin depends on the pharmacokinetic properties such as dose,route of administration and half-life in different tissues. Different doses of capsaicin have bidirectional effects on anti-cancer (20-50 mg/kg) and cancer-promoting (≥100 mg/kg),prevention and treatment of gastrointestinal ulcers (<50 mg/kg) and promotion of gastrointestinal ulcers (>100 mg/kg);long-acting analgesic effect of transdermal administration;the shorter half-life in different parts of the body such as liver,kidney,intestine,lung and blood restrict its clinical use in the body. This article reviews the structural characteristics of the capsaicin family and the main pharmacological activity and pharmacokinetic properties of capsaicin,while many studies have shown that the short half-life and low bioavailability of capsaicin may be the main reasons that hinder the clinical application in vivo. Capsaicin analogues with enhancing activities and overcoming metabolic defects may be the direction of developing a new generation of capsaicin drugs.