If you are allergic to menthol don’t use this product. It will result in normal allergic reactions like bad skin irritation, itching, swollen, red rashes and in severe cases, tightness in the chest and trouble breathing, which will need medical attention. Many Wintergreen products contain menthol and it is always stated on the packaging. However some like the arnica oil and the magnesium range do not contain menthol and may be a better option to try.