Menthol in pain relief and recovery
Menthol is a substance of natural origin, which is obtained from vegetable mint oil by steam distillation. Menthol can also be synthetically produced. At room temperature, menthol is a crystalline, light or colourless and waxy substance. Menthol tastes and smells like peppermint and has a characteristic odor of mint. Menthol is a fat-soluble substance, and is therefore easily absorbed through the skin.
Menthol is a safe substance to use. It is used in groceries of different kind and in other products as additive, flavoring and scent. Menthol is used, among others, in sweets, toothpastes, cosmetics, different treatment products for animals and in cigarettes.
In addition to its taste and scent features, menthol also possesses a cooling effect. Its cooling effect is utilized in different cold gels, creams, plasters and sprays. The cooling effect is also used in sweets for refreshing both mouth and breath.
Despite having been used since ancient times, the mechanism of action of menthol was clarified only as late as in 2002. The cooling effect of menthol is transmitted by the TRPM8 receptor. The TRPM8 is activated at temperatures which do not cause pain; i.e. at tissue temperatures of 25 – 28°C. Menthol increases the activation temperature. In addition to its cooling effect, menthol possesses several biological effects, which are used within the field of sports and athletics, and in light of latest knowledge, also in the treatment of different states of pain.
In sports and athletics menthol is known to speed up the recovery and improve the training response. When menthol is applied onto the skin 15 minutes before a training session, the blood flow remains increased for a little less than an hour. In long-lasting training sessions, the cooling menthol gel helps the athlete to find power to more effectively carry out the entire session. In cases where a menthol cream has been applied after a tiring session causing muscular pain, the pain has decreased and the power production of the muscles been improved.
A regular use of menthol during the training period has improved both endurance and oxygen uptake, and decreased the formation of lactic acid during aerobic training. In strength training the muscular mass and power production have been improved, when menthol has been applied onto the trained muscle groups.
The healing of injuries may also be improved by the use of menthol gels and creams. The gels contain alcohol, and are therefore not suited for children. Accidental applications on mucous membranes should also be avoided. A menthol cream is, on the contrary, suitable for children (e.g. in growing pains), as those products usually do not contain any alcohol.