Do you want an antiperspirant, a deodorant -- or both? Antiperspirants block the sweat ducts, reducing perspiration and the odor that often goes with it. Deodorants contain bacteria-fighting ingredients to reduce odor, but do little to prevent sweating. Many products contain both antiperspirant and deodorants to do both.
Do you want scented, unscented or fragrance-free? Scented deodorants can smell pleasant and mask odor, but some people prefer unscented varieties (although "unscented" deodorants actually contain masking fragrances). If you're sensitive to fragrances, look for deodorants marked "fragrance-free."
Do you have sensitive skin? If antiperspirants have given you a rash in the past, don't put them on right after showering or shaving -- that's when they're most likely to irritate skin. If that doesn't help, try a different active ingredient. Some people react badly to antiperspirants with aluminum chloride, others to aluminum zirconium trichlorohydrex glycine. Some find sprays, gels or roll-ons more irritating than solids. Some get rashes from natural deodorants.
Do you need "clinical strength?" These antiperspirants promise to keep you drier than regular antiperspirants, and doctors and users say the best ones really do work, however their higher concentrations of active ingredients make the more likely to cause skin irritation.
There isn't much difference between men's and women's deodorant. A quick look at the ingredient list of products sold to men and women confirms that they are basically the same. The main differences lie in fragrance, packaging and marketing.
"Natural," aluminum-free products cannot prevent perspiration. Their ingredients do not block sweat ducts and therefore only provide deodorizing benefits.
Allow antiperspirants to dry completely before dressing. Yellow stains on clothes are caused by a reaction between antiperspirant ingredients and proteins on the skin. Allowing products to dry completely after application will minimize staining as well as white marks left behind on clothes.
Better yet, apply antiperspirant to clean underarms at bedtime. "Clinical-strength" antiperspirants often tell you to apply at bedtime, but experts say this is really the best time to apply any antiperspirant. Since you sweat less at night, the active ingredient will have time to penetrate the sweat ducts.
If over-the-counter deodorants fail, consult your doctor. About 3 percent of people have hyperhidrosis (excessive sweating), and there are several methods to treat it. Prescription antiperspirant (Drysol) is the first line of defense. Iontophoresis, which uses a mild electrical current to thicken the outer layer of skin and turn off sweat production, is very effective for sweaty hands and feet. Botox injections can be used at the site of excessive sweating. MiraDry, a relatively new noninvasive treatment, uses microwaves to permanently eliminate underarm sweat glands.