Open your gym bag. Find your mouthguard. Smell it. If you just pulled a face, you're not alone.
A mouthguard spends an hour or two in a warm, wet mouth, gets thrown into a dark, closed gym bag, and goes back in your mouth the next day. That's the ideal setup for bacteria and fungus to build up.
Why your mouthguard smells
- Bacteria from saliva and plaque stick to the surface and form a film.
- Moisture stays trapped if you put it away wet.
- Heat and darkness in a gym bag speed everything up.
- Scratches and bite marks give bacteria places to hide that rinsing doesn't reach.
The smell is the warning sign. A dirty mouthguard means bacteria and fungus going straight back into your mouth every session.
How to clean your mouthguard after every session
- Rinse it in cool water straight after training. Not hot: most mouthguards are made from thermoplastic that softens and warps with heat.
- Brush it gently with a soft toothbrush and mild soap, or a little toothpaste without harsh whitening grit.
- Rinse again to remove any residue.
- Let it dry completely before storing it.
- Store it in a ventilated case, not loose in your bag and not sealed while wet.
Deep clean once or twice a week
Brushing removes most of the film, but not everything in the scratches. Soak it once or twice a week:
- Use a cleanser tablet made for mouthguards or dental appliances and follow the soak time on the pack.
- Rinse thoroughly afterwards and let it dry.
REST ROUND Mouth Guard Cleanser Tablets are made for this. Drop one in water, soak, rinse, done.
What not to do
- No boiling water or dishwasher. Heat warps the fit.
- No bleach or strong alcohol-based mouthwash. They can damage the material and irritate your mouth.
- No sharing. Ever.
- No leaving it in a hot car. Same warping problem.
Store it right
Most of the smell comes from storage, not use. A good case should let air in so the mouthguard can dry, and keep it off the bottom of your bag next to wet shorts and gloves. Our 2-in-1 Mouth Guard Clean & Store Case lets you soak and store in one, and the Mouth Guard Clip Case clips to your bag so it isn't buried.
When to replace your mouthguard
- It no longer fits snugly or falls out.
- There are holes, tears or deep bite-through marks.
- It still smells after a proper deep clean.
- You've had braces, dental work or new teeth come through.
For regular training, many athletes replace a boil-and-bite mouthguard every few months to a season. Custom-fitted guards last longer if cared for. Ask your dentist if you're unsure.
Don't forget the rest of your bag
A clean mouthguard in a dirty bag gets dirty again. Gloves, shin guards and headgear hold the same bacteria. Our guide to cleaning your BJJ and MMA gear bag covers the rest, and the REST ROUND Protocol sets out the full daily routine.
Rinse it. Brush it. Dry it. Soak it weekly. Replace it when it's done.