Methyl salicylic acid is similar to that of Aspirin that shows anesthetic properties by blocking the voltage-operated sodium channels in pain-receptor neurons. Menthol molecule binds and stimulates the TRPM-8 receptor protein that produces a sensation of cold (pain in extreme cases) when stimulated. Camphor is approved by the FDA for topical use as a pain reliever and anesthetic. It acts as a counterirritant and numbs the nerve endings, preventing the transmission of pain sensations.