How to Prevent Cold Sores: 7 Steps That Lower Your Risk
Written by Celso Bufano. Updated October 16, 2026. Every health fact links to its source.
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Short answer: you can’t stop cold sores forever, because the virus stays in your skin for life (NHS). You can have fewer of them. The two steps with the best support are avoiding your triggers (especially strong sun) and, if you get them often, daily antiviral tablets from a doctor.
Cold sores are also called fever blisters. Everything here applies to both names.
1. Know your triggers
The NHS names illness, sunshine and periods as common cold sore triggers. Its page on herpes outbreaks also lists stress, alcohol, smoking and a weak immune system (NHS).
Keep a simple note each time a cold sore starts: what happened in the days before? After a few outbreaks, most people see a pattern.
2. Protect your lips from the sun
Use a lip balm with SPF 15 or higher when you are outdoors, and avoid sunbeds (NHS). This is the easiest step and costs almost nothing. Reapply after eating or swimming.
3. Ask your doctor about daily antivirals
If you get cold sores often, a doctor can prescribe antiviral tablets. MedlinePlus says that if you get sores frequently, “you may need to take these medicines all the time.” Of all the options on this page, this one has the strongest evidence.
4. Have a plan for the first tingle
Prevention sometimes fails. Keep an antiviral cream at home and start it at the first tingle — it works best before the blister appears (NHS). Our guide explains each stage: how to get rid of cold sores fast.
5. Be extra careful when you are ill
Illness is a common trigger (NHS). When you have a cold or the flu, watch for the first tingle and have your cream ready. Drinking enough water also helps when you have a sore (NHS).
6. Don’t share — and don’t spread it
Cold sores are contagious from the first tingle until they are completely healed (NHS).
- Don’t share lip balm, cups, cutlery or towels.
- Don’t kiss anyone, especially babies, while you have a sore.
- Wash your hands after touching a sore, and don’t touch your eyes.
7. Be realistic about supplements
L-lysine is the supplement most people try. A 2017 review found it did not seem to work at doses below 1 gram a day, with some positive results at higher doses but conflicting studies (Mailoo & Rampes). Read our full article: L-lysine for cold sores.
Other supplements are sold with the promise of fewer outbreaks. None of them replaces antiviral medicine. If you are considering one, start with our comparison of cold sore supplements.
When to see a doctor
See a doctor or pharmacist if you get cold sores very often, if a sore is near your eye, if it doesn’t heal within 10 days, or if your immune system is weak (NHS).