Nothing really beats a steamy shower to relax after a hard workout.

And good hygiene is how we protect ourselves from infections, and the social stigma of being smelly. But do you really need a daily shower to stay clean, or is it doing more harm than good?

It turns out, there aren’t any definite rules, but some scientists have recommendations based on what we know about the biology of our skin — and what might be living on top of it. Your skin is a giant organ that physically blocks harmful stuff from getting inside your body. It’s covered in a bustling community of bacteria, fungi, viruses, and even teeny-tiny arthropods.

They make up what’s known as your skin microbiome. For the most part, researchers think that these microbes you carry with you are pretty harmless. But as you interact with the world, you can pick up other microbes that could make you sick.

And when you, like, rub your eyes or put food in your mouth, your hands can help those germs slip past your skin and get into your body. That’s why washing your hands with soap is so important, especially if you work in medicine or food service. See, soap is a surfactant, which means it’s made of molecules that can bind to water and things like dirt, oils, or bacteria.

This lets you rinse all that junk away. And fewer germs means a lower chance of infections. But what about washing the rest of your body?

Well, your skin has glands that are always producing sweat and oils, which cools you down and keeps your skin moisturized and healthy. But there’s a fine balance. Certain bacteria break down sweat, and release smelly molecules like thioalcohols.

And if your skin has too much dirt, dead skin cells, or oils, your pores can get clogged, leading to problems like acne. So showering with soap can help get rid of some sweat and oil, to manage your looks and smell. And in some cases, like the night before a surgery, a doctor might tell you to shower with an antimicrobial soap, which has extra chemicals to kill microbes.

If a surgeon is making cuts in your skin, they don’t want any potentially dangerous stuff sneaking in. On the other hand, showering too often might not be great for you either. For one, it can mess with the microbes that naturally live on your skin.

And since soap and water wash away oils, your skin might get too dry so the outer layer cracks, making it easier for disease-causing microbes to slip into your body. So dermatologists seem to say that daily showers where you scrub everywhere with soap is probably overkill, unless you sweat a lot, like people who work out every day. Otherwise, showering every couple of days should be just fine, to keep your skin microbiome healthy and happy.

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