Replace your toothbrush as soon as you feel better after COVID. While the virus on your bristles drops dramatically within 12 to 24 hours of drying, swapping for a fresh brush eliminates any lingering risk to you and, more importantly, to others in your household. If you use an electric toothbrush, you only need to replace the head, though you should also wipe down the handle with a household disinfectant.
How Long the Virus Lasts on Bristles
Coronaviruses can survive on plastic surfaces for up to 72 hours under ideal lab conditions. Toothbrush bristles are a slightly different story, though, because they’re exposed to air and dry out between uses. A lab study that contaminated toothbrushes with a coronavirus and an influenza virus found that viral levels dropped sharply once the brush was left to air-dry. After 12 hours of drying, the coronavirus on the toothbrush head fell below detectable levels. When the brushes were rinsed with water before drying, no infectious virus could be recovered after 12 hours at all.
That means if your toothbrush sits untouched overnight, the amount of live virus on it plummets. But “low” is not the same as “zero,” and the back of the brush head (the smooth plastic side) retained slightly higher viral levels than the bristles even after 24 hours. So while the risk decreases quickly with time, it doesn’t vanish on every surface of the brush.
Can You Reinfect Yourself?
This is the question most people are really asking. Once your immune system has fought off COVID, it produces antibodies that protect you from the same strain for at least a short window. Reinfecting yourself with your own toothbrush in the days right after recovery is considered unlikely for that reason. The bigger concern is household transmission: if your brush touches or sits next to a family member’s brush, or if someone accidentally grabs yours, those low levels of surviving virus could potentially reach someone who hasn’t been sick yet.
Toothpaste Helps, but Not Enough to Skip Replacing
Toothpastes containing zinc or stannous compounds have been shown in lab tests to neutralize 99.9% of the virus that causes COVID after two minutes of contact. That’s reassuring for your daily brushing routine while you’re sick, since it means the act of brushing itself reduces viral load in your mouth and on the bristles. A clinical study of about 50 hospitalized COVID patients confirmed that certain toothpaste and mouthwash formulas substantially reduced the amount of virus in the mouth, at least temporarily.
Still, toothpaste doesn’t sterilize the entire brush. Residual virus can cling to the base of the bristles, the back of the head, and the handle, none of which get full toothpaste coverage. So while brushing with an antiviral toothpaste is a smart move during illness, it’s not a substitute for replacing the brush afterward.
If You Can’t Replace It Right Away
Sometimes you recover on a Sunday night and there’s no spare brush in the house. In that case, you can disinfect your current brush to bridge the gap. A few options that reduce bacterial and viral load:
- Antibacterial mouthwash soak: Swish the brush head in mouthwash for 30 seconds after each use.
- Hydrogen peroxide: Soak the bristles in a 3% hydrogen peroxide solution for a few minutes, then rinse.
- Baking soda solution: Mix two teaspoons of baking soda into one cup of water and soak the brush.
- UV sanitizer: If you own one, UV toothbrush sanitizers have been found to outperform both saline and antiseptic mouthwash at killing pathogens on bristles.
One caution: some experts note that soaking multiple toothbrushes in the same disinfecting solution could spread germs between them rather than eliminate them. If you’re disinfecting, do each brush separately.
Storing Your Brush During Illness
How you store your toothbrush while you’re sick matters as much as when you replace it. Keep your brush completely separate from other household members’ brushes. That means not sharing a cup, a holder, or even a drawer. Store it upright with the bristles facing up so air circulates and the head dries faster, since drying is what kills the virus most effectively. Even a travel cap is fine as long as it has ventilation holes.
Keep the brush at least a meter (about three feet) from the toilet. The virus sheds in feces and urine, and flushing can aerosolize small droplets. Closing the toilet lid before flushing is a simple habit that reduces contamination on nearby surfaces, including exposed toothbrushes. And it should go without saying, but don’t share toothpaste tubes during an active illness either. Squeeze the paste onto a clean surface first if you must share a tube, so the nozzle never touches a contaminated brush.
Electric Toothbrush Users
You don’t need to throw out the entire unit. Replace the brush head, which is the part that contacts your mouth and harbors the virus. Then wipe down the handle with a disinfectant wipe or a cloth dampened with rubbing alcohol, paying attention to the area where the head connects to the body. The handle itself doesn’t go in your mouth, but you touch it with hands that have been near your face, and moisture from rinsing can drip down into crevices.
The Standard Replacement Rule Still Applies
Outside of illness, the American Dental Association recommends replacing your toothbrush every three to four months, or sooner if the bristles look frayed or splayed. A brush with worn bristles cleans less effectively regardless of germs. If your COVID illness happened to fall near the end of that cycle, you were overdue for a swap anyway. Keeping a spare brush in a drawer is a low-cost way to make sure you’re never stuck using a compromised one after being sick.