Personal care product manufacturers make big money off of our fear of armpit stains and body odour. Visit the drugstore deodorant and antiperspirant aisle, and you could work up a sweat trying to decide which product to choose.

What is the difference between antiperspirant and deodorant?

Keep in mind two important facts about sweat: it's wet and it has no scent. That's right: sweat only stinks because of the bacteria that live on or under our skin. Antiperspirants are made to deal with the wetness part, and deodorant handles the stink of bacteria.

The terms get swapped all the time, and some formulas do double-duty, acting as both antiperspirant and deodorant. But the two work quite differently, and each is regulated differently, too.

Health Canada labels deodorant as a cosmetic product, since it is used only to mask or neutralize the body odour caused by bacteria. An antiperspirant, on the other hand, is considered a "drug" because it actually temporarily changes the function of the skin, suppressing the flow of sweat.

How do they work?

Deodorant: Our armpits are home to many sweat glands, creating two warm and tucked-away spots where bacteria can thrive. To make our armpits a little less bacteria-friendly, deodorants contain ingredients that are acidic or salty. No bacteria to mix with the sweat means no smell. Some deodorants also contain fragrance or perfumes to mask unpleasant body odours.

Antiperspirant: Check the label of most antiperspirant, and you'll find aluminum compounds as the active ingredients. These compounds absorb into the skin, temporarily plugging up the sweat ducts, stemming the flow of sweat. That "plug" only lasts for a little while, so that's why people have to reapply antiperspirant to keep dry.

Which product should I choose?

Since many products actually include both antiperspirant and deodorant ingredients, you may not even be thinking too much about your decision to use one or the other. It's really an issue of personal choice. Decide based on your personal needs. First, consider which sweat side effect you want to deal with: the wetness or the smell - or both?

For some, the sweat-and-stink-fighting combo of a two-in-one works best. Others opt for deodorant only. Choose your preferred scent, or lack of scent, and consider how you like a product to feel when you put it on - do you prefer wet or dry? Options exist for sensitive skin, and there are also a variety of natural, aluminum-free alternatives, like the ones made from mineral salt crystals.

Do I need to use the new, stronger "clinical" antiperspirant formulas?

Some antiperspirants and deodorants are labeled as "sport" or "clinical-strength". Some are available by prescription, while others can be found on drugstore shelves. For those with hyperhidrosis (extreme sweating), this kind of product may help to reduce perspiration and the odour that comes with it. And it may work well on days when we need a little more sweat-proofing (going for a job interview, running a marathon - that kind of day).

For normal days, a regular-strength formula will probably do. Whether an antiperspirant is labelled "regular," "extra," or "maximum-strength," you're still reducing your sweat rate by about 20% to 30%. Keep in mind that no products completely eliminate sweat.

Are antiperspirants and deodorants really safe to use?

A while back, people began sending around emails warning about the link between aluminum in antiperspirants and breast cancer risk. This link may have originated because women are often told not to wear antiperspirants or deodorants before a mammogram. Residue from the products can show up on X-rays and be mistaken for an abnormality in the breast. So far, the FDA, the American Cancer Society, and the National Cancer Institute have said that no existing scientific or medical evidence has been found to link the products to breast cancer.

The only verified risk of using either deodorant or antiperspirant is skin irritation. Most formulas are pH-balanced, meaning they are not so acidic as to cause skin reactions. Still, anyone who develops a rash or experiences irritation from using a product should discontinue use. Never use either antiperspirant or deodorant on broken, cut skin.

What are some natural alternatives?

Deodorants: You can find products that are hypoallergenic, unscented, and without artificial colouring. Until a few years ago, it was hard to find mineral salt crystal deodorants, and when you did it came in a hard-to-apply rock-like form. Nowadays, though, it can be rolled right on like other deodorants.

One easy way to avoid the need for deodorant at all is to practice good underarm hygiene: keep your armpits dry and clean, and you can get away without using it as often. In a pinch, pat your armpits with a damp washcloth sprinkled with baking soda. It neutralizes the odour!

Antiperspirants: If you're eco-minded or worried about potential health risks of aluminum, your best choice may be to avoid antiperspirants altogether. Perspiration is one of our body's natural cooling mechanisms, so maybe it's best to not sweat it.