You’ve probably heard rumors about deodorant and antiperspirant since pretty much the day you started wearing them. Some say that antiperspirant is bad for you, that deodorant messes with your microbiome, and that natural options are better. Others say natural deodorants don’t work. So what’s the real lowdown? Let’s separate fact from funk.

First things first: What causes stinky pits?
It all comes down to bacteria. Your sweat is just water and salt, which doesn’t smell, but once it comes in contact with the (totally normal) bacteria that lives on your skin, you get body odor.

The difference between deodorant and antiperspirant
When it comes to your armpits, you’ve basically got two options: deodorant, which kills the the bacteria in your armpits that cause them to smell, and antiperspirant, which has the same antibacterial properties, plus aluminum, which temporarily plugs the sweat ducts. (There are also antiperspirant and deodorant combos.) Aluminum is the ingredient that you’ve probably heard warnings about — those who opt for regular or natural deodorant often do so because they believe the aluminum in antiperspirant causes illnesses and messes with your microbiome.

Antiperspirant and kidney disease
One health concern that’s worth noting: your kidneys. They help remove excess aluminum from the body, and while the FDA gives the thumbs up to antiperspirant overall, they do require that every stick contains a warning for those with kidney disease to check with a doctor before using.

How about your microbiome?
Everyone’s got their own personal microbial system, aka your microbiome. The word is used to describe all of the organisms that live inside you, including bacteria. What you use on your armpits does affect your microbiome — people who use antiperspirant, for example, have 50 times fewer bacteria in their armpits than those who don’t. Although you might hear people use the microbiome to make the case for natural deodorants, the fact that what you use on your armpits (just like what you use on the rest of your body) affects our body’s bacteria is nothing to be alarmed about — it’s simply how deodorant and antiperspirant works, and it’s not intrinsically good or bad. The whole reason to buy it is that it changes our body’s bacteria!

The natural options — and do they work?
All that said, there are still reasons to switch to natural deodorants — just because the scientific link between health problems and regular deodorants and antiperspirants isn’t there yet, you might prefer to err on the side of extra caution. Whatever the case, if you’re picking up your deodorant stick from a natural store, you should still check the ingredients for anything you don’t want in there. You’ll have plenty of natural options, from those made with bacteria-killing tea tree oil to a salt rock. The best way to find the most effective one for you is to try them — our bodies and microbiomes are all different after all, so what works great for one person might not work at all for someone else. That said, this guide can get you started on your search.

Diana Vilibert is a freelance writer and copywriter living in Brooklyn, NY. She loves flea markets, martinis, to-do lists, traveling, and wearing leggings as pants. You can see more of her writing at www.dianavilibert.com and follow her on Twitter at @dianavilibert.