How to Get Rid of a Cold Sore in 24 Hours
Start cold sore treatment within the first 24 hours: a 1-day prescription antiviral or docosanol cream at the first tingle, pain relief, and steps that keep it from spreading. The sore still takes 1 to 2 weeks to heal.
You will end up with a plan for the first 24 hours of a cold sore: treatment started at the first tingle, the pain under control, and the people around you protected.
No cream, pill, or home remedy clears a cold sore in 24 hours, and the American Academy of Dermatology says you cannot clear one overnight. What you can do in 24 hours is start treatment and bring the pain down. The prescription regimens in step 3 finish within 1 day and are meant to start at the first tingle. Expect the sore itself to take 1 to 2 weeks, or up to about 2 days less with early treatment (step 8).
Act the moment you feel the tingle
The NHS says a cold sore usually starts with a tingling, itching, or burning feeling in the spot where it is about to appear. Cleveland Clinic calls this the prodromal stage. Blisters follow within 24 hours by Cleveland Clinic's timeline and within 48 hours by the NHS's. That gap is your window to start treatment. The American Academy of Dermatology recommends treating a cold sore before it even appears or at the very first sign. The antiviral trials in step 3 told people to start at the very first symptoms, and that early start is the setting in which the treatments were shown to work. If your doctor has already prescribed an antiviral for cold sores, take it now, exactly as the label directs. If you have nothing on hand, buy docosanol cream at a pharmacy today (step 2) and call your doctor about a prescription (step 3). Cleveland Clinic says oral antivirals work best when started within the first day or so, and do little after that.
Good to know: Learn your own warning sign. Cleveland Clinic lists tingling, itching, pain, or numbness on the lip or nearby skin. Once you know which one comes first for you, you can start treatment sooner next time.
Apply an over-the-counter antiviral cream
Docosanol (sold as Abreva and as store brands) is the only over-the-counter antiviral cream approved by the FDA for cold sores, Cleveland Clinic says. The label covers adults and children 12 and older. Ask a doctor before using it on a younger child. Wash your hands, then take a little cream out with a clean cotton swab, so the tube stays clean, as the AAD advises. Apply it to the sore at the first tingle and rub it in gently, as the label directs. Use it 5 times a day until the sore has healed, scab included. Keep it out of your eyes and the inside of your mouth, and do not share the tube, which the label says can spread the infection. In two trials with 737 adults, published together in the Journal of the American Academy of Dermatology in 2001, docosanol started at the first tingle or redness healed sores in a median of 4.1 days, 18 hours sooner than a placebo cream. It did not significantly raise the share of sores that never formed (40% versus 34%). Wash your hands after every application. If the sore gets worse or has not healed in 10 days, stop and see a doctor, as the label says.
Get a prescription antiviral and take it at the first tingle
Cleveland Clinic calls prescription oral antivirals the quickest way to get rid of a cold sore. Call your doctor or book a telehealth visit as soon as the tingle starts, because the benefit depends on starting early. Your doctor can prescribe valacyclovir (Valtrex) or famciclovir (Famvir). Both courses finish within 1 day. The valacyclovir label gives 2 grams every 12 hours for 1 day, for adults and children 12 and older, started at the earliest symptom, and says its benefit has not been established once a bump, blister, or sore has formed. In two placebo-controlled trials published in Antimicrobial Agents and Chemotherapy in 2003, this 1-day course cut the median length of an outbreak by about 1 day. It raised the share of sores that never fully formed by only about 6 percentage points, a difference that was not statistically significant in the first trial. The famciclovir label gives a single 1500 mg dose for adults, taken at the first sign or symptom. In a 2006 trial of 701 patients who took it within 1 hour of their first symptoms, the first blister healed in a median of 4.4 days, against 6.2 days on placebo, and the single dose worked as well as two doses in 1 day. Both labels lower the dose for people with kidney problems, so tell your doctor if you have any.
Good to know: Ask your doctor for a prescription you can keep at home, so the next course can start within minutes of the tingle. In the famciclovir trial, patients kept the pills and took them within 1 hour of their first symptoms.
Ease the pain and swelling
Wrap ice or a cold pack in a clean cloth before it touches your skin, because Cleveland Clinic warns that ice applied directly to a cold sore can cause damage. Hold it against the sore for 5 to 10 minutes, several times a day, beginning when the tingling starts. Use a fresh cloth each time. The compress eases pain, redness, and swelling, but it does not speed up healing. For more relief, take acetaminophen (paracetamol) or ibuprofen as the package directs. The NHS says not to give aspirin to children under 16. Cleveland Clinic adds that numbing gels with lidocaine or benzocaine, often sold for dental pain, ease the burning without making the sore heal faster.
Keep your hands off the sore
Leave the sore alone between treatments. Every touch can carry the virus to your fingers, and Cleveland Clinic notes that touching a cold sore can cause a herpes infection on the finger, called herpetic whitlow. When you do touch it, wash your hands with soap and water before and after, as the NHS advises. Do not pick at the sore, pop the blisters, or peel off the scab. Cleveland Clinic says popping a sore can spread the infection and that the sore needs to heal on its own.
Heads up: Never touch your eyes after touching a cold sore. Cleveland Clinic lists ocular herpes, an infection of the eye, among the complications of the virus. If your eye becomes painful, red, or blurry during an outbreak, see a doctor right away, and see one for any cold sore near your eye, as the AAD advises.
Avoid spreading it to others
Cold sores are caused by the herpes simplex virus, usually type 1 (HSV-1). The NHS and Cleveland Clinic both say they are contagious from the first tingle until the sore has completely healed, and Cleveland Clinic says they are most infectious within 24 hours of forming. The World Health Organization adds that the virus can spread from skin that looks normal, though the risk is greatest when there are active sores. Until the sore has healed, do not kiss anyone or have oral sex, which can give a partner genital herpes, as the NHS warns. Do not share cups, utensils, straws, lip balm, razors, or towels. If you use a shared water bottle at home, switch to your own. Do not kiss a baby while you have a cold sore. The NHS warns that it can lead to neonatal herpes, which is very dangerous to newborns, and Cleveland Clinic calls it life-threatening. If you cannot avoid holding a baby, cover the sore, wash your hands often, and keep your utensils and towels to yourself, as Cleveland Clinic advises. Take the same care around anyone with a weakened immune system.
Protect your lips from the sun
The NHS names sunshine as one of the things that can trigger a cold sore, alongside illness and periods. The NHS sets SPF 15 as the floor for lip balm in the sun, and the AAD recommends broad-spectrum SPF 30 or higher, which meets both. Use it while the sore heals, from a tube you will throw away once the sore has healed. The AAD and Cleveland Clinic both say to discard lip products used during an outbreak. After it heals, wear SPF 30 lip balm year-round if the sun sets off your cold sores. The AAD says it may help prevent new ones, and tells you to reapply it every 2 hours outdoors and after eating, swimming, sweating, or licking your lips. The AAD lists cold and hot weather and dry, cracked lips as triggers too, so keep your lips moisturized in every season.
Let the scab heal on its own
Around day 3 or 4, the blisters stop oozing and crust over into a golden-brown scab, by Cleveland Clinic's timeline. This is a normal part of healing. The scab covers the sore while it heals. Leave it on. If the scab cracks or feels tight, dab on a thin layer of petroleum jelly with a clean cotton swab. Cleveland Clinic says keeping the lips moist stops the sore from drying out and peeling. The scab falls off on its own, usually 6 to 14 days after the outbreak started. Cleveland Clinic says a cold sore usually lasts 1 to 2 weeks, and the skin under the scab can stay pinker than usual for a few days after. Started at the first tingle, the treatments in steps 2 and 3 took between 18 hours and about 2 days off healing in their trials.
If the sore is not healing, or if it is near your eye, or if you have eczema or a weakened immune system, see a doctor (FAQ 6 below has the full list). Once it heals, throw away the lip products you used during the outbreak (step 7). Before the next outbreak, ask your doctor for an antiviral prescription to keep at home (step 3), and keep SPF 30 lip balm with you (step 7).
Questions we get asked about this
Answers from experience, not a textbook.
No. The American Academy of Dermatology says you cannot clear a cold sore overnight, and many heal without treatment in 7 to 14 days. What fits into 24 hours is the treatment itself. The prescription regimens in step 3 finish within 1 day and took about 1 to 2 days off healing in their trials when started at the first tingle. A cold compress and a pain reliever can bring the pain down the same day (step 4).
A prescription oral antiviral, valacyclovir or famciclovir, started at the first tingle (step 3). Cleveland Clinic calls oral antivirals the quickest way to get rid of a cold sore. Without a prescription, start docosanol cream at the first tingle (step 2).
From the first tingle until the sore has completely healed, the NHS and Cleveland Clinic both say. Cleveland Clinic says it has healed when the scab has fallen off and the skin underneath looks normal again, and that the first 24 hours after the sore forms are the most infectious. Step 6 lists what to avoid until then.
Cleveland Clinic lists illness, stress, sun exposure, injury to the mouth area, and hormonal changes such as a period or pregnancy. The AAD adds dry or cracked lips, lack of sleep, cold and hot weather, and pressure on the lips from procedures such as dental work or lip fillers. Before one of those procedures, tell the person doing it that you get cold sores. To find your own triggers, keep a note of what you were doing before each outbreak, as the AAD suggests.
A few have small trials behind them. A 2025 systematic review in the Journal of Integrative and Complementary Medicine found 7 randomized trials with 1,250 patients in total. Lemon balm creams reduced pain and swelling, and propolis, olive leaf extract, and a sage-rhubarb cream did as well as or better than acyclovir on healing time. The authors judged 5 of the 7 trials to raise some concerns about bias and called for larger trials. Cleveland Clinic says the same remedies need more research, and that lysine is unlikely to help. Use one alongside an antiviral, not instead of it, and test it on your arm first, as Cleveland Clinic advises for aloe and manuka honey.
See a doctor if the sore has not started to heal after 10 days, as the NHS advises, or lasts longer than 2 weeks, the AAD's limit. See one sooner if the sore is near your eye, if you have several sores or a lot of pain, if you have eczema, or if a condition or medicine weakens your immune system, such as HIV, chemotherapy, or drugs taken after an organ transplant. Cleveland Clinic adds a first outbreak, a fever, and sores inside the mouth or swollen gums. If you get cold sores 6 or more times a year, the AAD says a dermatologist can prescribe a low daily dose of an antiviral to reduce outbreaks. If a newborn was exposed to a cold sore or has skin blisters, call the pediatrician right away.