Water bottle hygiene is probably something you never thought about before, but, we warn you, after reading this, it may never be far from your mind again. There are certain things we all kind of forget to wash: our phone screens, our keyboards, our sunglasses, our makeup brushes. Guilty, guilty, guilty, guilty.

One such item that could definitely do with a wash? Your water bottle. Yes, your water bottle that you refill every day; your water bottle that you drink from at your desk, at the gym, during a hike, watching TV; your water bottle that has been collecting bacteria and, quite possibly, limescale for months. Apologies if you are suddenly filled with dread realizing that the last time you cleaned your water bottle was never—but we have some pretty awful news for you.

It's probably filthy. In fact, according to a 2022 study , the average reusable water bottle contains 40,000 times as much bacteria as a toilet seat . (Oh.

My. God. Ew.

) But before you go rushing off to soak your water bottle in bleach, we have a little more information for you. Enter nutritionist Michaella Mazzoni , who tells us why water bottles are so dirty and how we should be cleaning them. How often should you wash your water bottle? Ok, this might come as a shock—but according to Michaella , we should be washing our water bottles every single day.

Yep. She recommends using “warm, soapy water” for the job. What are the health risks of not washing your water bottle consistently? It's safe to say .