# Why does menthol (e.g. peppermint) feel cool to the tongue?

Especially when drinking water after the fact, mint can give a sharp cold sensation inside one's mouth. What process causes the sensation to occur?

• There is a really excellent, detailed answer to this here (boundlessthicket.blogspot.com/2012/04/…). If you'd like me to summarize it as a formal answer, I'd be happy to...but it's really written up very well. – Janice DelMar May 31 '12 at 20:15
• – unor Jun 22 '16 at 16:21

Menthol acts at the TRPM8 protein which forms an ion channel that allows $\ce{Na+}$ and $\ce{Ca^2+}$ ions to flow into cells and this sends a signal saying "cool" to the brain. (As an aside, this protein monitors temperature across the body and not just on the tongue.) Cold temperatures actually change the confirmation of this protein, which allows the ions to flow more freely, and sends the signal to the brain. Menthol, on the other hand, stabilizes the open channel (allowing ions to flow even more freely) and also...