Antiperspirant Awareness: It's Mostly No Sweat

Last Editorial Review: 10/7/2005

By Carol Rados

Offensive body odor is against the law in libraries in San Luis Obispo County, Calif. A code of conduct, officials say, is necessary to ensure that one person's right to use a public library doesn't infringe on the rights of another and law enforcement officers have the authority to remove library patrons who smell bad.

An extreme measure? Perhaps. But social awareness, coupled with the availability of dependable personal care products, may be a more practical way to hold body odor at bay.

The agency defines antiperspirant as a drug product applied topically that reduces the production of sweat (perspiration) at the site where it is applied. Antiperspirants, according to the Food and Drug Administration, can safely and effectively reduce sweat for up to 24 hours, if formulated and tested properly. And for most, this means protection against both wetness and odor.

The FDA issued a final rule in June 2003 establishing conditions under which over-the-counter (OTC) antiperspirants are generally recognized as safe and effective (GRASE), and are not misbranded. The final rule establishes allowable ingredients and labeling for the products.

In October 2004, the agency reopened the record on this final rule to consider one manufacturer's request to double the length of time--from 24 hours to 48 hours--during which an OTC antiperspirant is considered to be effective. The request in this case, called an enhanced duration claim, applies to the testing and labeling of this particular claim.

Matthew R. Holman, Ph.D., an FDA scientist in the Division of Over-the-Counter Drug Products, says that the agency needs scientific evidence that extended duration products work. "Manufacturers have to back up such claims with studies," he says. The FDA must be satisfied that the testing is valid for 48 hours.

Under the Federal Food, Drug, and Cosmetic Act, the FDA legally defines products by their intended uses. Therefore, drugs are defined as products intended for treating or preventing disease or for affecting the structure or any function of the body. Antiperspirants are considered drugs because they affect the function of the body by reducing the amount of sweat that reaches the skin.

But different laws and regulations apply to each type of product. Some products, for example, must comply with the requirements for both drugs and cosmetics. This happens when a product has two intended uses, for example, when an antiperspirant is also a deodorant. Cosmetics are defined as substances that cleanse, beautify, promote attractiveness, or alter the appearance, without affecting the body's structure or function. Deodorants are regulated as cosmetics because they promote attractiveness only by masking odor, not by reducing sweat.

Unlike drugs, neither cosmetic products nor cosmetic ingredients are reviewed or approved by the FDA before they are marketed. But the agency urges manufacturers to do any necessary testing to prove that their products are safe. And cosmetic makers must put a warning statement on the front labels of those products that have not been safely tested. The agency can take action against cosmetic products found to cause harm after they are on the market.

Why People Sweat

Whether the extra heat comes from hardworking muscles in the gym, from over-stimulated nerves due to stress, or from high air temperatures and humidity, sweating is the body's way of naturally regulating its temperature.

During extended, vigorous activity, a person can lose several quarts of fluid through the evaporation of perspiration. A pea-sized bead of sweat can cool about one quart of blood 1 degree Fahrenheit, according to the Mayo Clinic, and only about 1 percent of the body's sweat is produced under the arms.

Sweat itself is odorless. It's the bacteria that live on the skin and break down the sweat that cause the unpleasant odor. Keeping underarms dry and smelling good are big business. According to the Mintel Group, a marketing and research organization in Chicago, Americans spent an estimated $1.7 billion in 2004 on antiperspirants and deodorants. These products, designed for both men and women, include aerosols, sprays, pumps, roll-ons, solid sticks, gels, and creams. The FDA refers to these various forms of application as "dosage forms."

Given the amount of money people spend on personal hygiene products, it would seem that an offensive body odor shouldn't be much of a problem. However, according to Gray's Anatomy, most people have several million sweat glands distributed over their bodies, providing plenty of opportunity for odors to develop.

There are two types of sweat glands. The eccrine glands, which we are born with and which are the most numerous, produce most of the sweat in the underarms. These glands open directly onto the surface of the skin. Apocrine glands, which are triggered by emotions, develop in areas abundant in hair follicles, such as the scalp, underarms, and genitals. These glands only begin to secrete sweat after puberty, and have little, if anything, to do with temperature regulation.

The sweat glands are located in the middle layer of skin called the dermis, which is also made up of nerve endings, hair follicles, and blood vessels. A sweat gland is a long, coiled, hollow tube of cells. Sweat is produced in the coiled part in the dermis, and the long part is a duct that connects the gland to the opening, or pore, on the skin's outer surface. When the sweat gland is stimulated, the cells secrete perspiration that travels from the coiled part of the gland up through the straight tube and out onto the skin's surface.


Sweat is odorless. See Answer

The American Academy of Dermatology (AAD) says that perspiration is 55 percent to 60 percent fluid, mainly water. Perspiration also contains salt (sodium chloride), as well as trace amounts of other substances, such as ammonia, calcium, chloride, copper, lactic acid, phosphorous, and potassium. These substances, called electrolytes, help to regulate the balance of fluids in the body. The most abundant electrolytes are phosphorous and sodium, which cause sweat to sting the eyes and give sweat its salty taste.

The loss of excessive amounts of salt and water from the body can quickly dehydrate a person and can lead to circulatory problems, kidney failure, and heat stroke. So, although it's literally cool to sweat, it's also important that people drink fluids when exercising or when outside in high temperatures.

Antiperspirants 101

People tend to interchange the words "antiperspirant" and "deodorant," but as regulated by the FDA, they are not the same. Antiperspirants have an aluminum-based compound as their main, "active" ingredient, which can be any number of compounds within an established concentration and dosage form. The active ingredient gives antiperspirants their sweat-blocking ability by forming a temporary plug within the sweat duct that stops the flow of sweat to the skin's surface.

The aluminum-based compound is always the first ingredient listed on the back of an antiperspirant container. A few common active ingredients are aluminum chloride, aluminum chlorohydrate, and aluminum zirconium. An "inactive" is any ingredient besides the active ingredient. Some of the inactive ingredients in an antiperspirant include talc, fragrance, and butane, used as an aerosol propellant.

With so many choices available, how do people choose a product that's right for them?

"Looking for a favorite scent is a great way for a consumer to narrow down the search," says Michelle Vaeth, a spokeswoman at Cincinnati-based Procter & Gamble Co. Product development, she says, is constantly driven by what consumers want, and the consumer products company regularly conducts detailed home interviews, quantitative questionnaires, and surveys to get this information.

Another factor is aesthetics, or how a product feels when applied to the skin. "Maybe a woman enjoys the cooling sensation of a clear gel and loves the fact that there's no residue," Vaeth says. Roll-ons tend to have a wet, cool, refreshing feeling upon application, and Vaeth says that many people like how this product feels on their skin after it dries--"they can tell it's still there and working."

Jonathan Hague and Cindy Dumlao, who both work in product development with Unilever, an Anglo-Dutch consumer products company, agree that people tend to go with products they trust. "They want good, high-performance products," says Hague, "and what our consumers think is important to us."

So important, Dumlao adds, that Unilever keeps a database of 18,000 consumers who come to participate in the effectiveness of antiperspirant formulas at the company's clinical and consumer testing facility.

"Basically," she says, "we put people in a hot room, about 100 degrees Fahrenheit, with a relative humidity of 35 percent, and collect their sweat."

The facility is also where "new formulations and fragrances are discovered," says Hague. In his experience, "stick antiperspirants appear to be the preferred dosage form in North America."

Many factors control how effective an antiperspirant is, such as the type and size of the active ingredient used in the formulation.

"Different actives have different levels of effectiveness at stopping sweating," says Timothy J. Long, Ph.D., a scientist with P&G Beauty. The active ingredient also must be pH balanced--basic enough, Long says, not to cause irritation to the skin, but acidic enough to form the solid plugs in the sweat ducts.

The antiperspirant effectiveness test required by the FDA determines that a product is effective or ineffective in its final formulation. But, says Holman, "we do not have any data that suggest any dosage form is better than another." He also says there's a lot of variability between dosage forms. An antiperspirant in finished form may vary in degree of effectiveness because of minor variations in formulation, or in individual interpretation of the directions for its use.

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.


Dehydration: Causes, Symptoms & Signs See Slideshow

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.

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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.

According to the National Cancer Institute (NCI), the breast cancer-antiperspirant myth first appeared in the form of an e-mail in the 1990s, and continues to resurface and recirculate about every year or so. The false information suggests that antiperspirants contain harmful substances, which can be absorbed through the skin or can enter the body near the breasts through nicks in the skin caused by shaving. The e-mails also suggested that antiperspirants keep a person from "sweating out toxins," resulting in the spread of cancer-causing toxins via the lymph nodes.

But the NCI says that no existing scientific or medical evidence links the use of underarm antiperspirants or deodorants to the subsequent development of breast cancer. The FDA, the Mayo Clinic, the American Cancer Society (ACS), and the Cosmetic, Toiletry and Fragrance Association agree. Razor nicks may increase the risk of skin infection, but not cancer.

According to the ACS, sweat glands are not connected to the lymph nodes. Most cancer-causing substances are removed by the kidneys, are released through urine or by the liver, and are eliminated with feces. The ACS says that lymph nodes may help to clear some toxins from the body, but they do not release these toxins through sweating. Sweat is not a significant route for eliminating toxins from the body.

And a study of 813 women with breast cancer and 703 women with no history of breast cancer, published in the October 2002 issue of the Journal of the National Cancer Institute, found that antiperspirants do not cause breast cancer.

Some speculate that the myth could have been started by women being told not to wear antiperspirants or deodorants before a mammogram. They were told this, not for safety reasons, but because residue from these products appearing in the X-ray is often mistaken for an abnormality in the breast.


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