#1 Doctor Recommended Brand Certain Dri is one of the only brands that offers a variety of solutions specifically developed to help people who suffer from excessive underarm sweating. In fact, it is one of the original clinical antiperspirant brands and the #1 Doctor recommended brand for people with excessive sweating. Certain Dri Prescription Strength Clinical - Roll-On This antiperspirant is the strongest in the Certain Dri line with 12% Aluminum Chloride, and is the most effective antiperspirant you can buy without a prescription. Aluminum Chloride is the strongest and most effective active ingredient available in antiperspirants and is the same active ingredient in many prescription formulations. Aluminum Chloride is the #1 doctor recommended active ingredient for excessive sweating. Because of the strength of this active ingredient, it is only available in roll-on form. Who is Certain Dri Prescription Strength Clinical Roll-On for? Anyone suffering from hyperhidrosis or excessive sweating looking for the strongest protection available without a prescription. Directions: 1. Apply Certain Dri antiperspirant to underarms at bedtime. That’s because the active ingredient works best while you sleep to stop perspiration all day. It will not wash off the next day, even after bathing or showering. 2. Apply sparingly to completely dry armpit. Apply Certain Dri sparingly – only a few strokes under each arm. To reduce the risk of irritation, be sure underarms are completely dry before applying. 3. For added deodorant protection, Certain Dri Everyday Strength Clinical antiperspirant + deodorant may also be reapplied in the morning for an extra layer of freshness and protection.