Apply to the underarms and use throughout the day, if needed. If you have a history of sensitive skin, please test on a small area inside your wrist for 2 to 3 days prior to using. If sensitive to baking soda, we recommend that you try an apple cider vinegar wash before applying. This helps alleviate any reaction and allows you to continue using natural deodorant.Jena’s Notes: If your skin is sensitive, shave the night before. Also, a little goes a long way. If N3 is staining your shirt, you’re using too much product. Blot underarms with a dry washcloth or apply less.