Antiperspirant Awareness: It's Mostly No Sweat (cont.)

For example, while a product label may instruct the user to hold a can of aerosol six inches from the underarm and then spray, Holman says, how long each person sprays, swipes, glides, wipes, or rolls will vary. Therefore, the directions don't directly reflect the conditions of effectiveness. But Holman adds that consumers can be assured that products are effective whether they are gels, sticks, aerosols, or others, if they pass the FDA's test.

Antiperspirants and the FDA

"People feel that those products on the shelf are a direct reflection of what we regulate," says Holman. "But mostly, it's based on what's selling."

Like prescription drugs, the FDA oversees OTC drugs to ensure that they are properly labeled and that their benefits outweigh their risks. OTC drugs account for more than 100,000 products on the market that involve about 800 active ingredients. The FDA classifies these nonprescription drugs by treatment category, such as laxatives, antacids, and antiperspirants, and evaluates their ingredients. So, rather than review thousands of individual antiperspirant products, the FDA evaluates the far fewer active ingredients found in them.

Most OTC drugs are subject to rules called monographs, which state requirements for categories of nonprescription drugs, such as what ingredients may be used and for what intended use. If the standards of the OTC monograph are met, premarket approval of a potentially new OTC product is not necessary.

The FDA is mainly concerned about claims being made for a product, Holman says. For example, in the familiar slogan, "strong enough for a man but made for a woman," the company had to prove that the product was tested in both men and women because there are physiological differences between them. Similarly, testing must confirm marketing statements such as "so effective you could skip a day."

By contrast, Holman says that if a company claimed that a new antiperspirant ingredient is effective, "it would require a new drug application because the ingredient is not already included in the antiperspirant monograph as generally recognized as safe and effective."

Holman also says that manufacturers tend to test antiperspirant products on more women than men. One reason seems to be underarm hair. Women are required to shave two days before testing to keep hair to a minimum and to minimize skin irritation. "With that said, skin irritation related to shaving is not a major safety concern because it is not serious or life threatening," Holman says. "And common sense dictates women will not keep using a particular product if it causes irritation."

The important thing to remember, says Holman, "is that antiperspirants don't completely eliminate sweat." According to the FDA's testing standards, the most effective products, those that claim "extra strength" or "maximum strength," are based on at least a 30 percent sweat reduction rate in most people. Regular strength products test at a 20 percent sweat reduction rate in most people.

Sweating Too Much, or Not Enough

If the complex biological mechanism of perspiration goes awry, it can result in either excessive perspiration (hyperhidrosis) or little or no perspiration (anhidrosis), a potentially life-threatening condition.

Dermatologists at the AAD say that excessive sweating is normal when a person is anxious or has a fever. However, excessive sweating can be a chronic condition and may signal other medical conditions such as thyroid problems, low blood sugar levels, a nervous system disorder, or the onset of menopause.

Excessive sweating is more than a mild nuisance that some people experience. According to the AAD, hyperhidrosis affects about 8 million Americans. Depending on where it occurs on the body, hyperhidrosis has several treatment options, including topical agents such as prescription antiperspirants, oral medications, and surgery. Prescription antiperspirants contain higher doses of the active ingredient aluminum chloride. Skin irritation is the main side effect with prescription antiperspirants such as Drysol (aluminum chloride hexahydrate).

In July 2004, the FDA approved Botox (botulinum toxin type A), a drug that is used to temporarily erase wrinkles for cosmetic purposes, to treat severe underarm sweating (primary axillary hyperhidrosis) that cannot be managed by topical agents. Available by prescription only, botulinum toxin type A is a protein produced by the bacterium Clostridium botulinum. This protein works by interrupting the chemical messages released by nerve endings that tell the sweat gland when to sweat.

Administered into the armpit, small doses of an injectable form of the sterile purified botulinum toxin stop release of the chemical messenger acetylcholine that supplies nerves to the eccrine glands, thereby temporarily paralyzing the nerves in the underarm that stimulate sweat production.

To avoid the possibility that Botox treatments can mask a potentially serious disease, the FDA advises patients to be evaluated by a doctor for other possible causes of excessive sweating. Botox is approved for treatment of the underarms, but not for excessive sweating of other sites such as the feet and palms.

The Cancer Myth

The rise of the Internet has made it easy for false health claims, scary stories, and rumors to reach millions of people in a matter of minutes. One such myth says that antiperspirants may cause breast cancer.