capsaicinoids

Capsaicinoids are a family of nitrogen-containing compounds found in chili peppers (Capsicum species) that give peppers their characteristic pungency. The most studied capsaicinoid is capsaicin, followed by dihydrocapsaicin; together they account for much of the heat in many peppers. Other natural capsaicinoids include nordihydrocapsaicin and homocapsaicin, with synthetic analogs used in research and medicine.

Capsaicinoids are produced in the peppers’ placenta and stored in the surrounding white pith. Their concentration varies by species, cultivar, maturity, and growing conditions, which explains the wide range of heat observed among peppers.

The physiological effect of capsaicinoids is mediated by the TRPV1 receptor, a heat- and pain-sensing ion channel on sensory neurons. Activation produces the burning sensation and flushing characteristic of chili exposure. With repeated exposure, TRPV1 can become desensitized, reducing pain signaling; this desensitization property underpins the use of capsaicin in certain topical analgesics.

Applications and safety: In food, capsaicinoids contribute flavor and heat. In medicine, capsaicin-containing creams and patches are used for some neuropathic and musculoskeletal pain conditions. Side effects include a transient burning sensation on application, skin irritation, and, less commonly, gastrointestinal discomfort if ingested in excess. Capsaicinoid products should be used with caution in children and individuals with certain skin conditions, and medical guidance is advised for those on specific medications.

Chemically, capsaicinoids are lipophilic vanilloid alkaloids and are primarily metabolized in the liver by cytochrome P450 enzymes.