Menthol is a compound obtained from Peppermint Oil. The anti-fungul and anti-bacteria action of Menthol has been studied extensively. Menthol Crystals finds diverse applications because of its characteristic aroma, flavor, and its cooling effect. Menthol Crystals can be used in perfumes, cosmetics, analgesic balms, lotions, creams, shampoos and conditioners. Recommended usage level is 0.5 - 8 %. **NOTE: Menthol crystals must pass through the Phoenix, AZ postal system, where temperatures easily exceed 100 degrees F in summer months. Your crystals may show up melted. You can place them in your fridge and lightly hit them with a rubber mallet. Please do not order if this is a problem for you.