Transient receptor potential vanilloid 1 (TRPV1)

Transient receptor potential vanilloid 1, or TRPV1, is an ion channel on pain-sensing nerves that opens in response to heat, acid and capsaicin, the hot component of chili peppers.

TRPV1 sits on the endings of small sensory neurons in skin, joints, gut and airways. It opens when tissue temperature rises above roughly 43 degrees Celsius, when the surroundings become acidic, as in inflamed or injured tissue, or when capsaicin binds it, and inflammatory chemicals lower its threshold so that ordinary warmth begins to hurt. Repeated or prolonged activation desensitizes the channel, which is why topical capsaicin is used on the skin for some kinds of nerve pain. Anandamide also activates TRPV1, giving the channel a place in endocannabinoid signaling.

TRPV1 is one of the best-characterized non-cannabinoid targets of CBD: in cell experiments CBD activates and then desensitizes it in a way resembling capsaicin. Whether that action contributes to any effect in people is unresolved, and the finding remains at the mechanistic stage.