Once you’ve been exposed to the stomach bug, there’s no guaranteed way to stop the virus from taking hold. But several practical steps can meaningfully reduce your odds of getting sick, especially in the first 12 to 48 hours before symptoms would appear. The virus responsible for most stomach bugs, norovirus, is extraordinarily contagious, yet the actions you take immediately after exposure still matter.
Why Acting Fast Matters
Norovirus symptoms typically hit 12 to 48 hours after exposure. That window is your opportunity. The virus spreads through direct contact with a sick person, touching contaminated surfaces, or eating contaminated food. It takes fewer than 20 viral particles to cause infection, which is a remarkably small amount. For context, a single episode of vomiting can release billions of particles into the air, and those particles can travel up to 25 feet from where someone got sick.
This is why casual, brief contact with a sick person can be enough. If someone in your household vomited in the bathroom an hour ago, viral particles are likely on the faucet, the toilet handle, the light switch, and possibly the floor and walls nearby.
Wash Your Hands With Soap and Water
This is the single most important thing you can do. Norovirus is a non-enveloped virus, which means alcohol-based hand sanitizers are far less effective against it than they are against flu or cold viruses. Soap and water is the standard the CDC recommends for norovirus specifically. Scrub thoroughly for at least 20 seconds, getting under your nails and between your fingers.
Wash your hands every time you touch a surface in a shared space with a sick person, before eating or touching your face, and after using the bathroom. If hand sanitizer is all you have in the moment, use it, but follow up with soap and water as soon as possible. Don’t rely on sanitizer alone.
Disinfect Surfaces Aggressively
Regular household cleaners and antibacterial wipes are not strong enough to kill norovirus. You need a bleach-based solution or a disinfectant specifically registered by the EPA as effective against norovirus (check the label for this claim). The CDC recommends a chlorine bleach solution of 1,000 to 5,000 parts per million, which works out to 5 to 25 tablespoons of standard household bleach (5% to 8% concentration) per gallon of water.
Focus on high-touch surfaces: doorknobs, light switches, faucet handles, toilet flush levers, countertops, refrigerator handles, and remote controls. Norovirus can survive on hard surfaces like plastic and countertops for more than two weeks, so a surface that looks clean can still be infectious long after a sick person touched it. If someone vomited or had diarrhea in a specific area, disinfect everything within a wide radius. Anything porous that can’t be sanitized and was within range of a vomiting episode should be thrown out.
Isolate the Sick Person When Possible
If you’re living with someone who has the stomach bug, limiting contact is one of the most practical things you can do. Ideally, the sick person uses a separate bathroom. If that’s not possible, disinfect the shared bathroom after every use. The sick person should avoid preparing food for others, not just while symptomatic but for at least two days after symptoms stop. People continue shedding the virus in their stool for days to weeks after they feel better.
Designate specific towels, cups, and utensils for the sick person. Don’t share anything that touches the mouth or face.
Handle Laundry Carefully
Soiled clothing, towels, and bedding are common transmission routes that people overlook. Wear disposable gloves when handling contaminated laundry. Wash items on the hottest water setting the fabric allows. If the items are bleach-safe, add bleach to the wash cycle using the CDC-recommended concentration. Dry on the highest heat setting as well. Don’t shake out dirty laundry before putting it in the machine, as this can send viral particles into the air.
Skip the Grape Juice and Probiotics
A popular home remedy claims that drinking grape juice after exposure can change the pH of your digestive tract enough to block the virus from multiplying. There is no scientific evidence supporting this. Your body’s internal pH levels are tightly regulated and not meaningfully altered by drinking juice.
Probiotics are another common suggestion, but the research here is also discouraging. A large U.S. study of 971 children treated across 10 medical centers tested one of the most widely sold probiotic strains (sold as Culturelle) against a placebo in kids with stomach bugs. The probiotics had no measurable effect. A parallel Canadian study using a different probiotic strain found the same thing. As the lead researcher put it, they added no benefit and weren’t worth the cost.
What You Can Realistically Expect
Even with perfect precautions, norovirus is difficult to dodge entirely when someone in your household is sick. The viral dose needed for infection is incredibly small, and the virus is hardy enough to survive on surfaces for weeks. These steps reduce your exposure, but they don’t eliminate it.
If you do get sick, symptoms typically last 1 to 3 days. The biggest risk is dehydration from vomiting and diarrhea, so keeping fluids down is the priority. Small, frequent sips of water or an oral rehydration solution work better than trying to drink large amounts at once.
The most protective thing you can do in the 48-hour window after exposure is simple and unsexy: wash your hands constantly, bleach every surface you can, and minimize contact with the sick person and anything they’ve touched. No supplement or home remedy comes close to matching the effectiveness of those basics.