Topical antiperspirants are the first-line therapy for all forms of hyperhidrosis including armpits, palms and soles. These topical agents work by creating a plug in the sweat duct thereby preventing the ability to sweat. A variety of different chemical formulations are available over-the-counter. Aluminum chloride (hexa hydrate) is the most effective topical antiperspirant. This ingredient can be found in various concentrations. The maximum over-the-counter concentration is 12% aluminum chloride. The stronger the preparation the more irritating it may be to the skin. The prescription antiperspirant ( 20% aluminum chloride) under the tradename Drysol, is currently on backorder. Patients may try obtaining an equivalent product online through Amazon. General tips on application of antiperspirants: Antiperspirants should be applied to dry skin at bedtime. (Using a hair dryer on cool setting to dry the area first before application may be helpful). If aluminum chloride mixes with sweat, it produces hydrochloric acid and is irritating to the skin. That’s why the skin must be bone dry before application. And since we tend not to sweat at bedtime, that is the best time to apply it. Antiperspirants need to stay on the skin for 6 to 8 hours before being washed off. Tips on reducing irritation from antiperspirants: When starting out, consider using the strong preparation every other night initially. Reduce application to twice-weekly once success is achieved. Use the lowest concentration of aluminum chloride possible. Apply a moisturizer after application of the antiperspirant. Apply a weak preparation of hydrocortisone twice a week maximum. Once reduction of sweating is noted ( usually within 1 to 2 weeks of starting a strong antiperspirant), maintenance therapy usually only requires twice a week application. With regard to safety concerns: No evidence exists that links the use of aluminum containing antiperspirants to Alzheimer’s disease No clear link exists between the use of aluminum containing antiperspirants and breast cancer