Menthol Crystals, CAS# 89-78-1, it is extracted from peppermint, which is also known as Mentha piperita, brandy mint, and lamb mint. Menthol Crystals has been used for liver and gallbladder complaints, loss of appetite, nausea, vomiting, respiratory infections, menstrual cramps, toothache, the common cold, cough, and fever. Topically, Menthol Crystals has been used for muscle and nerve pain and as an antiseptic