Hi, I'm Craig, my armpits emit a pleasant essence of lilac, and this is Mental Floss on YouTube. Today, I'm going to answer Zraluer's big question- "I've got a question for you- How does deodorant work, in terms of anti-perspirants, and B.O.?"

Well, Zraluer, you actually mentioned two substances in your question. Deodorant is a product that masks body odour, or B.O. Anti-perspirant does the same thing, but it also prevents sweating, which deodorant does not do. And today I'm going to talk to you about both of them- so let's get started.

(Intro)

First things first, let's talk about sweat. (Let's talk about sweat, baby!) Your sweat comes from sweat glands, found in different regions of your body. You have millions of these, but we're going to focus on the armpit, because that's probably/hopefully where you're putting your deodorant, or anti-perspirant.

The sweat from those glands actually doesn't smell. Sweat is mostly just water, and some minerals, like sodium, potassium and calcium. Body odour comes from the bacteria on your skin, like Corynebacterium, which breaks sweat down into acids.

Unfortunately, these resulting acids, including Propio- Well, these acids (pointing to the right side of the frame), I'm not going to try and pronounce it- these acids smell, and the hair in this region only amplifies the problem.

So, let's move on to how we solve that problem. There are a lot of different products, with different ingredients out there, but I'm going to explain what's in most standard deodorants and anti-perspirants.

Deodorant typically has a fragrance, and alcohol. The alcohol in deodorant kills the pesky bacteria that's making you smell.

Generally, alcohol will make me smell- like, alcohol. Or vomit, depending on the night.

Sometimes, deodorant also contains triclazone, which is a compound that slows bacterial growth, too, so deodorant is masking the odour, and fighting the bacteria on your skin.

Anti-perspirants usually also have fragrance and alcohol, but in addition to those ingredients, they contain an aluminum compound, usually aluminum chlorohydrate, which reduces sweat.

These actually clog those sweat glands I described earlier, and that's how anti-perspirants are able to prevent sweating.

Just so you know, there are some urban legends out there that blame aluminum compounds for things like Alzheimer's Disease and breast cancer, but there's no evidence that that's true. It is true, that they were created by aliens, though.

Another note - it's the aluminum compounds in your anti-perspirant that causes yellow sweat stains- eww. But at least now you know that your sweat isn't yellow.

If you have a big question of your own that you'd like answered, leave it below in the comments. Thanks for watching Mental Floss on YouTube. Smell you next week!