Menthol is an organic compound extracted from peppermint or other mint oils. It is sold in its crystalline form and melts just slightly above room temperature (ie when you touch it). It looks like shards of glass or broken crystal and has the most beautiful fragile tinkling sound when you shake it out of the bag. Mentha arvensis is the primary species of mint used to make natural menthol crystals. It was first isolated from peppermint oil in 1771 in the West, but has been widely known and used in Asian medicine for far longer.
Menthol is to the cold sensation what capsaicin (extracted from chilies) is to hot. It triggers cold-sensitive TRPM8 receptors in the skin which gives a cooling sensation when inhaled, eaten or applied to the skin, without causing an actual change in temperature.
Menthol has analgesic (pain relieving) properties and helps to relieve skin irritations, sore throats and nasal congestion. It is also used to treat sunburn, fever and muscle aches. When menthol is used orally, it is used in the form of peppermint oil, and is widely used in toothpastes, cough medicines, lip balms, mouthwashes, chewing gum and cigarettes.
In traditional Thai and Asian medicine, menthol is used for nausea, diarrhea, indigestion, headache, colds, sore throat and muscle pain. Commonly in Traditional Thai Massage, menthol is used in conjunction with camphor.
Arun Thai Natural uses menthol in Phlai Traditional Thai Massage Oil and Beeswax Balm (warming) and Ginger Cassia Traditional Thai Massage Oil and Beeswax Balm (cooling).