One major component of peppermint essential oil is menthol, which gives peppermint its smell, flavour, and tingling sensation. The skin on your face, including your lips, will process the menthol as a tingling and slightly burning sensation thanks to the nerves in the face. The process is similar to how our taste buds process spicy food. This sensation is completely safe and can even promote focus and attention. Peppermint oil is FDA-approved for use as both a flavour and fragrance.