Capsidol Topical Analgesic Capsicin, applied topically, triggers a local irritation, which is symptomatically manifested as erythema and a burning sensation, sometimes itchy. This effect is generally attributed to a neurogenic inflammation process and is interpreted through the release of the substance P neurotransmitter. In a second phase, the action of capsaicin is related to antinociceptive effects, the duration of which ranges from a few hours to weeks. After repeated application, the depletion of substance P from the neuron leads to a prolonged loss of sensitivity to burning and pain.