Because of its mostly cool menthol content (85%), Peppermint is found in most liniments to relieve painful muscle spasms and arthritic conditions. Its energetic scent was said to be an aphrodisiac in ancient times.
Essential oils have a much smaller molecular weight than carrier oils and therefore pass through the skin quicker. When the molecular weight of an ingredient is under 500 Dalton (the standard measurement unit of atomic mass) then it is thought to be able to freely pass through the top layer of the skin, the stratum corneum.
There are different ways of using aromatherapy so if you think inhaling it is the only way, think again because here are a few other options.