is the best non-prescription deodorant on the market. It contains 20 percent aluminum zirconium tetrachlorohydrex gly as its active ingredient, which is the strongest concentration you can get without a prescription, according to TheBeautyBrains.com, a website run by scientists in the cosmetics industry. These same scientists also report that Secret Clinical Strength deodorant is not as harsh as prescription-strength products, either. Testers say that it also performs well in stressful and strenuous situations. Consumers at Drugstore.com, TotalBeauty.com, MakeupAlley.com and Amazon.com, where thousands of users give it a combined average of 4 out of 5 stars, say that it keeps them dry all day long but that it is more expensive than other drugstore deodorant brands. A couple of users complain that it dries out their skin, while others say using a small amount and following directions helps keep irritation at bay.