Should you replace your toothbrush after being sick?
Probably not, and honest advice admits it: the evidence for automatic replacement is weak. Once you’ve recovered from a cold or flu, your immune system has beaten that virus, and reinfecting yourself from your own brush is considered unlikely. Rinsing well and drying fully matters more. The practical exceptions: strep throat, shared brush cups — and the fact that a few dollars of peace of mind is allowed to just be that.
Written by Reuben S., who runs BARE and packs every order. Published 15 August 2026
Why the folklore says yes and the evidence shrugs
“Bin your toothbrush after being sick” has the shape of good advice — it’s cautious, cheap and easy to remember, which is how it spread. But when researchers have gone looking for the mechanism, it mostly isn’t there for the common cases. By the time you’re better, your immune system has produced exactly the response that beats the virus on your brush; catching the same cold again from your own bristles is the scenario the folklore imagines, and it’s considered unlikely.
We took the same position, in fewer words, in the replacement guide — and it’s worth noticing that the advice you’ll hear from careful dentists hedges the same way. When the evidence is thin, the honest sentence is “the evidence is thin”, not a rule.
What actually helps while you’re sick
- Separate your brush. If the household shares a cup, heads touching is the plausible transfer route — move yours apart for the duration.
- Never share the brush itself. True in health; truer now.
- Rinse well, dry fully. Moisture is what extends microbial survival on a brush. The everyday routine — rinse, shake, upright in open air — is doing more than any post-illness ceremony would.
The strep exception, and being honest about it
Bacterial throat infections — strep in particular — are where replace-your-brush advice is most often given, on the logic that re-exposure to bacteria is a different question than a beaten cold virus. Even here, evidence that brushes actually cause reinfection is thin. But this is also where the cost-benefit stops being interesting: a brush is a few dollars, strep is miserable, and swapping the brush once antibiotics have started is a cheap, reasonable call that your doctor may well make for you. Take their word over ours.
If you want the tidy habit anyway
There’s a version of this that makes practical sense without any germ theory at all: let the end of a proper illness be the trigger that resets your replacement clock. Most people run their brushes well past the three-month guidance anyway, so “new brush when I’m better” usually just lands the replacement closer to schedule — peace of mind and an overdue swap in one. (It’s the practical reason our brush comes in a pack of four: the next one is already in the drawer when any trigger — wear, illness, season — says now.)
The short version
- After a cold or flu: replacement is optional comfort, not evidenced necessity. Reinfecting yourself with a beaten virus is considered unlikely.
- While sick: separate your brush from shared cups, rinse well, dry fully.
- After strep: cheap enough to just do; follow your doctor.
- The schedule that actually matters is wear — three months, or sooner once bristles splay.
Common questions
01Do you need to throw away your toothbrush after a cold or flu?
The evidence for automatic replacement is weak, and honest advice says so. By the time you've recovered from a cold or flu, your immune system has beaten that specific virus, so reinfecting yourself from your own brush is considered unlikely. Rinsing well and letting the brush dry fully between uses matters more day to day. If a fresh brush is cheap peace of mind for you, take it — just know it's comfort, not a documented requirement.
02Should you replace your toothbrush after strep throat?
Strep is the case where replacement advice is most often given, because it's bacterial rather than viral and re-exposure is a different question than with a beaten cold virus. Evidence that brushes actually cause strep reinfection is thin, but a toothbrush costs a few dollars — after a bacterial throat infection, swapping the brush once you've started antibiotics is a reasonable, cheap call. Your doctor's advice outranks this page.
03Can you get sick again from your own toothbrush?
For the same cold or flu, it's considered unlikely: recovery means your immune system has dealt with that virus, and respiratory viruses also don't survive indefinitely on a dry brush. Drying matters — moisture is what extends microbial survival, which is why the everyday advice is rinse well and dry upright in open air rather than ritual replacement.
04What should you do with your toothbrush while you're sick?
Keep it apart from the household's other brushes so heads don't touch, don't share it, rinse it well after each use, and let it dry fully in open air. If you normally store brushes together in one cup, separating yours for the duration is the one genuinely useful precaution while someone in the house is unwell.
05Is it worth replacing a toothbrush 'just in case' after illness?
If it buys you peace of mind, yes — it's a few dollars and the calendar was probably part-way to the three-month replacement anyway. A tidy habit some people use: replace the brush when a proper illness ends, and treat it as resetting the replacement clock. Just don't confuse the comfort with necessity; the necessity is the three-month wear schedule, not the illness.
Nothing here is medical advice, and this page makes no claim that replacing or keeping a toothbrush prevents any illness. For your own health — especially anything bacterial, recurrent or serious — your doctor’s advice outranks every toothbrush website, this one included.