Cold Sores
Tingly, blistering sores on the lip from the herpes simplex virus. Very common, harmless for most adults, gone in about 10 days. The trick is speed: treat at the first tingle.
The cold sore ladder
Most cold sores heal on their own. Treatment shaves days off, and only if you start early. The tingle is your starting gun.
- Step 1 · Self-careHands off, ice on, SPF onCool packs for pain, SPF lip balm to block sun triggers, and no picking.
- Works
- Not tested for pain; SPF blocked UV-lamp-triggered sores in small trials, but real-sunlight results are mixed
- Cost
- About $5–10 for an SPF lip balm
- How long
- Until healed, usually 7–10 days
- Watch for
- Picking spreads virus and invites infection. Don’t share cups, towels or lip balm.
Squeezing a cold sore is not a treatment. It’s a distribution plan.
- Step 2 · PharmacyAntiviral cream (aciclovir)Dab on 5 times a day from the first tingle.
- Works
- Modest: heals about half a day faster than a dummy treatment (roughly 4.5 vs 5 days)
- Cost
- About $10–20 a tube
- How long
- 4–5 days
- Watch for
- Little point once it’s crusted. Dab, don’t rub, and wash hands after.
Works best on a sore that hasn’t fully arrived yet. Punctuality matters.
- Step 3 · PharmacySingle-dose antiviral tablets (famciclovir)Pharmacist-only: 3 tablets taken together, once, for adults who get repeat cold sores.
- Works
- Heals about 1.5–2 days faster than a dummy treatment (4.4 vs 6.2 days) when taken within an hour of the tingle
- Cost
- About $10–20 for the 3-tablet pack
- How long
- One dose. That’s it.
- Watch for
- Headache, nausea. Not for first-ever sores, children, pregnancy or weak immune systems without advice.
Keep a pack at home. Dawdling to the chemist tomorrow is how the sore wins.
- Step 4 · PrescriptionAntiviral tablets (valaciclovir), short courseFor bigger, frequent or nasty outbreaks.
- Works
- Shortens an outbreak by about 1 day vs a dummy treatment if started at the first tingle
- Cost
- About $15–40 on a private script
- How long
- 1 day (2 doses), started at the tingle
- Watch for
- Headache, nausea. Dose may change with kidney problems.
Same principle as step 3: early or not at all.
- Step 5 · PrescriptionDaily antiviral to prevent outbreaksFor people having many outbreaks a year, or before a known trigger (e.g. a ski trip).
- Works
- Roughly halves outbreaks: about 6 in 10 stay outbreak-free over 4 months, vs 4 in 10 on a dummy treatment
- Cost
- About $20–40 a month on a private script
- How long
- Months at a time, then review
- Watch for
- Headache, nausea. Doesn’t make you uninfectious, just less often.
For frequent flyers, not the once-a-year cold sore.
- Step 6 · SpecialistEye or skin specialistFor sores near the eye, cold sores on eczema, or a weakened immune system.
- Works
- Not tested in trials; standard care that prevents serious complications such as eye damage
- Cost
- Medicare rebates with a GP referral; specialist gaps vary
- How long
- Usually short-term, sometimes urgent
- Watch for
- Any red, painful or blurry eye with a cold sore needs same-day care.
Your eye is not the place for a home remedy.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Lysine supplementsTrials are small and mixed, with no clear benefit for treating or preventing cold sores.
- ToothpasteNo evidence, and it can dry out and irritate the skin around a sore.
- Essential oilsMostly lab studies and tiny trials. Tea tree on a raw lip can sting and cause allergy.
- Antibiotic creamsCold sores are a virus. Antibiotics don’t touch it.
What you can do
- Start treatment at the first tingle, itch or burn. Keep supplies at home.
- SPF 30+ lip balm in sun, wind and snow.
- No kissing babies, and no oral sex, while you have a sore.
- Don’t share cups, cutlery, towels or lip balm.
See your GP if
- Sores are big, spreading or not healed in 2 weeks
- You get them often
- You have eczema or a weakened immune system
- You’re pregnant, especially near the due date
See a doctor the same day for a cold sore near the eye, a painful red eye, or sudden spreading sores on eczema skin. A newborn with blisters, fever or poor feeding needs urgent care. If very unwell, call 000 (Australia) or your local emergency number. From a mobile, 112 works in most countries.
Common questions
Are cold sores contagious?
Yes, most when blisters are present, but the virus can spread even without a visible sore. Most adults already carry it.
Can you get rid of the cold sore virus for good?
No. It stays dormant in nerves and can reawaken with sun, stress, illness or periods. Treatment shortens outbreaks; daily tablets can reduce how often they happen.
What is the fastest cold sore treatment?
A single-dose antiviral tablet from the pharmacist, taken within an hour of the first tingle, heals sores about 2 days faster. Creams help a little less.
Is it safe to kiss a baby if I have a cold sore?
No. Herpes can be dangerous for newborns. Wait until the sore is fully healed, and wash hands before handling babies.
Helpful resources
- Raising Children Network: Cold soresCold sores in children and babies, and when to see a doctor. Free.
- Staying Healthy: Cold sores in childcareThe official national guide on whether a child can attend childcare with a cold sore. Free, Australian.
Evidence and more information
- Healthdirect: Cold sores
- NICE CKS: Herpes simplex (oral)
- Spruance et al: Aciclovir cream for cold sores, two trials (2002)
- Spruance et al: Single-dose famciclovir for cold sores (2006)
- Baker and Eisen: Valaciclovir to prevent cold sores (2003)
- Cochrane: Interventions to prevent cold sores (2015)
maladywise.com/cold-sores/