What it is
Menthoxypropanediol is a synthetic derivative of menthol.
What it does
Menthoxypropanediol is often used in lip plumpers. It works by irritating lips causing them to swell.
In addition, it is used as a fragrance to mask the smell of other ingredients in cosmetics and personal care products.
Menthoxypropanediol is twice as stong as Menthol and is therefore twice as irritating.