A storage stable L-menthol composition including a tablet, caplet, capsule, or sachet dosage form has therein a core containing crystalline L-menthol and at least one pharmaceutical excipient. A proteinaceous coating of a continuous film of proteinaceous material is over the core. The film is effective to substantially prevent the crystalline L-menthol from volatilizing and leaving the core when stored at a temperature of 40 degrees C. and 75% relative humidity from between 1 day to 30 days. The dosage form contains an effective amount of the crystalline L-menthol for treating a gastrointestinal disorder.