Menthol Crystal is a crystallized form of menthol, an organic compound found in peppermint and other mint plants. It is a white crystalline substance that is used as a flavor and fragrance in food, beverages, and cosmetics. Menthol Crystal is used to provide a cooling sensation upon application and is often used in cough drops and mouthwashes. It is also used in products to treat muscle and joint pain, and to reduce itching and inflammation.