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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, usually. Cold sores are diagnosed by photo and video and antiviral tablets prescribed while the 48-hour window is open; a sore near the eye, widespread sores, or a newborn who has been in contact need in-person care.
- What it is: a reactivation of herpes simplex virus type 1 in the nerve that supplies the lip; about 2 in 3 people under 50 carry HSV-1, most caught in childhood, and only some of them ever get visible cold sores.
- Timing: antiviral tablets started within 48 hours of the first tingle shorten a cold sore by a day or two and soften it; started at the crust stage they add almost nothing, so a standby supply for next time is the smarter plan.
- Stages: tingle, blister, weeping sore, crust, healed skin in 7 to 10 days without a scar; the weeping stage sheds the most virus and the sore is contagious from the first tingle until the crust has gone.
- Babies: neonatal herpes is rare but can be life-threatening, and a fresh cold sore sheds exactly that virus, so no one with a cold sore kisses a baby until it has fully healed.
- Emergency: call 112 or go to emergency care if a newborn who has been in contact with a cold sore develops blisters, fever, poor feeding or floppiness, or if someone with eczema develops rapidly spreading punched-out sores with fever.
Get in-person care instead if a sore sits close to your eye or your eye becomes red, watery or painful, if painful blisters are spreading rapidly across wider areas of skin, especially if you have eczema, or if you are significantly immunosuppressed. If a newborn baby develops blisters, fever or unusual drowsiness, or has been kissed by someone with a cold sore, treat it as an emergency and seek hospital care immediately.
How do you get rid of cold sores fast?
No treatment removes a cold sore overnight. The fastest realistic option is an antiviral tablet such as aciclovir or valaciclovir started within 48 hours of the first tingle, which can shorten healing by a day or two and soften the outbreak. Untreated, most cold sores crust and heal within 7–10 days. Antiviral creams help less than tablets.[1]
Tablets need a prescription, which is where fast access to a doctor matters: on Mobi Doctor, a licensed doctor can assess you over video at the tingle stage, usually within 15 minutes. When treatment fits, the doctor can prescribe it, with the prescription usable at a pharmacy near you. The honest version of "get rid of it fast" is: move early, treat the sore gently, and have a standing plan for the next one.
Listen: Cold Sores Treatment Online
The audio version of this topic from the Mobi Doctor podcast. Open the episode.
How an online consultation helps with cold sores
- Built for the 48-hour window: video appointments daily 7am–11pm CET mean the tingle you notice at breakfast can be assessed by a doctor while the window is still open.
- Tablets, not just creams: the doctor assesses whether episodic aciclovir or valaciclovir fits you, rather than leaving you to pharmacy creams alone.
- A plan for repeat offenders: frequent outbreaks can justify daily suppressive treatment and a standby supply strategy, agreed in one conversation.
- Protecting the people around you: clear, practical rules for newborns, partners and households with eczema, which is where cold sores genuinely turn dangerous.
📷 Take one photo at arm's length showing the whole mouth area and one sharp close-up of the sore itself, in daylight. At the tingle stage there may be almost nothing to see; that is fine, the story carries the diagnosis, and a photo of a previous outbreak helps too. If sores sit anywhere unusual, nose, chin, inside the mouth, near an eye or on a finger, photograph those as well.
What the doctor checks in an online cold sore consultation
The assessment is aimed at one decision above all: will antivirals genuinely help this episode, this person, right now? In a cold sore consultation, the doctor will typically check:
- The stage and the clock: tingle, blister, weeping or crust, and hours since it started, because tablets earn their keep in the first 48 hours and add little to a sore that is already crusting.[1]
- First episode or recurrence: a first infection can be a bigger illness, with mouth ulcers, gum pain, sore throat and fever, and is managed differently from the familiar lip-edge recurrence.
- Location: the lip border is standard territory; sores near the eye, in the nose, on fingers (herpetic whitlow) or spreading beyond one area change the plan.
- Frequency and triggers: how many outbreaks a year, and what sets them off: strong sun, fevers and colds, tiredness, menstruation, stress or dental work.
- Your skin history: eczema in you or your household matters, because herpes virus on eczema-damaged skin can spread dangerously (eczema herpeticum).[3]
- Immune status and pregnancy: immunosuppressing conditions and medicines, pregnancy and breastfeeding all steer the choice and dose of treatment.
- Contacts at risk: a newborn at home, a partner asking about transmission, or a job involving close contact with vulnerable people.
- Whether it is a cold sore at all: golden-crusted patches that keep spreading suggest impetigo, a bacterial infection treated completely differently.
What do the stages of a cold sore look like?
A cold sore runs a recognisable five-step course: a tingling, itching or burning patch at the lip for a few hours to a day; a cluster of small, tense, fluid-filled blisters; blisters bursting into a shallow, weeping sore, the most contagious stage; a yellowish crust that may crack; and healed skin at around 7–10 days, normally without a scar.[3][5]
Why cold sores come back
Cold sores are caused by herpes simplex virus, usually type 1 (HSV-1), which most adults worldwide carry, often picked up as a child from an affectionate relative.[2] After the first infection the virus retreats into the nerve that supplies the lip and stays there for life, reactivating when defences dip: strong sunlight, fevers and respiratory infections (the "cold" in cold sore), fatigue, menstruation, stress, or trauma to the area such as dental work or cosmetic procedures. Between one person and the next, and one outbreak and the next, frequency varies enormously; many carriers never blister at all.[2]
Are cold sores herpes?
Yes. A cold sore is oral herpes, and the same virus family causes genital herpes: HSV-1 can be passed from lips to genitals during oral sex, and increasingly causes first genital episodes. That is a reason for sensible precautions during an outbreak, not for shame; carrying HSV-1 is closer to the rule than the exception worldwide.[2] If you have questions about a genital episode, that page and its consultations cover testing, treatment and telling partners.
Can an online doctor prescribe cold sore tablets?
Yes. After a video assessment, the doctor can prescribe episodic antiviral treatment, a short course of aciclovir or valaciclovir to take at the first tingle, and, for people with frequent or severe outbreaks, discuss daily suppressive treatment. A prescription is never issued without a consultation.[1]
Timing honesty applies in both directions. If you consult at the tingle, tablets are worth taking that day. If the sore is already crusting, the doctor will usually say that tablets add little now, and instead agree a plan so the next outbreak is treated in its first hours: knowing your earliest warning sign, and having a consultation the moment it appears, is what actually shortens cold sores over a lifetime of them.
How do you stop cold sores from coming back?
You cannot remove the virus, but you can reduce outbreaks: high-SPF lip balm in strong sun (a reliable trigger), enough sleep, and early treatment of illness all help. For roughly six or more outbreaks a year, or fewer but severe ones, daily suppressive antiviral treatment substantially cuts frequency, reviewed after 6–12 months.[1][4]
During an outbreak, protect others and your own skin: no kissing until fully healed, no oral sex during an outbreak, own towel and cutlery washed normally, no sharing lip products or razors, wash hands after any touch, and do not touch the sore then rub your eyes. Replace or clean anything that lives on your lips, and leave the crust alone; picking restarts the clock.
Cold sores, newborns, pregnancy and eczema
The one situation where a cold sore is genuinely dangerous is around newborn babies. Neonatal herpes is rare but can be life-threatening, and a fresh cold sore sheds exactly the virus responsible, so the rule is absolute: no kissing babies while you have a cold sore, from anyone, however beloved, until it has fully healed, with careful hand washing before handling and no sharing of dummies or spoons.[2][5] A newborn who develops blisters, fever, poor feeding or unusual sleepiness after contact needs emergency hospital assessment.
In pregnancy, cold sores themselves are common and the priority is sensible treatment: aciclovir is the antiviral with the longest record of use in pregnancy, and the doctor weighs timing and need with you honestly; genital herpes near delivery is a separate, important topic covered on the genital herpes page.[1] In anyone with eczema, herpes virus can spread across the damaged skin barrier as eczema herpeticum: rapidly multiplying, punched-out sores with fever and feeling unwell, which is a same-day emergency, not a wait-and-see rash.[3]
Which cold sore treatment might the doctor recommend?
Treatment follows the stage, the frequency and the risk around you. This is the framework the doctors use, aligned with the cited guidance:[1]
Swipe sideways to compare →
| Presentation | Likely first step | Suitable for online care? | When referral or in-person care is needed |
|---|---|---|---|
| Tingle stage or first 48 hours of a recurrent cold sore | Episodic antiviral tablets (aciclovir or valaciclovir) started promptly[1] | Usually yes | Only if red flags are present |
| Blistered or crusting sore beyond about 72 hours | Honest advice: gentle care, protection of others, and a standby plan for the next outbreak | Usually yes | A sore that has not healed after two weeks needs an in-person look |
| Six or more outbreaks a year, or severe or scarring episodes | Daily suppressive antiviral treatment, reviewed after 6–12 months | Usually yes | Breakthrough outbreaks on suppression, or diagnostic doubt: specialist review |
| First-ever episode with mouth ulcers, gum pain and fever | Assessment, antivirals if early, fluids and pain control | Often, case-dependent | Children or adults who cannot drink enough: in-person care for hydration |
| Sore near the eye or a painful red eye; spreading sores with eczema; newborn contact | Urgent in-person or emergency care | No: triage only | Always; eye involvement risks herpes keratitis, eczema herpeticum and neonatal herpes are emergencies[3] |
Not sure which row is your outbreak? A doctor can tell you in one consultation.
See available times →Treatment options for cold sores
What you can do yourself
Keep the sore clean and leave it in peace: dab rather than rub, use a cold compress for throbbing, take paracetamol or ibuprofen for pain, and eat and drink on the other side of your mouth. Pharmacy aciclovir cream offers modest benefit and only when started at the very first tingle; hydrocolloid patches hide the sore and stop you touching it, which has its own value.[1] Daily SPF lip balm is the cheapest prevention there is. One thing that never helps is antibiotics: a cold sore is a viral infection, and antibiotics target bacteria, so they are only ever relevant if a sore becomes secondarily infected with spreading golden crusts.
Prescription treatment
A prescription is never issued without a consultation. After the assessment, the doctor can prescribe a short episodic course of aciclovir or valaciclovir for the current or next outbreak, or daily suppressive treatment for frequent recurrences, choosing dose and duration to fit your kidneys, other medicines, pregnancy or breastfeeding; famciclovir is an alternative antiviral.[1] For severe first episodes, treatment runs longer and hydration matters as much as the antiviral. Suppressive treatment is reviewed rather than automatic forever, and stopping it periodically to reassess frequency is standard, honest practice.
When cold sores are treated online, and when you need in-person care
Treated online: recurrent cold sores at any stage, with tablets when the window is open and a standby plan when it is not; frequent outbreaks needing suppressive treatment; first episodes in otherwise well adults; prevention planning around sun, illness and stress triggers; and sorting cold sores from look-alikes such as impetigo, angular cheilitis or chancre-type ulcers, with onward testing where needed.
In-person care: anyone with eye involvement or a painful red eye during an outbreak, to same-day in-person eye assessment; suspected eczema herpeticum, the same day; any newborn exposure or blistering, to emergency paediatric care; severe first episodes where drinking has become impossible, especially in children; immunosuppressed patients with spreading or slow-healing sores; and any lip sore that has not healed within two weeks, because a persistent ulcer needs an in-person examination to rule out other causes, including rarely skin cancer.
When to get in-person care
Seek emergency care, or call 112, if a newborn who has been in contact with a cold sore develops blisters, fever, poor feeding or floppiness, or if someone with eczema develops rapidly spreading, punched-out sores with fever. Get same-day in-person care for a red, painful or light-sensitive eye during an outbreak, for widespread sores in anyone immunosuppressed, and for a first episode where pain stops all drinking.
Treating a cold sore at home: what helps and what does not
Pharmacy antiviral creams help most when started at the first tingle, before the blister even shows, and petroleum jelly keeps the sore comfortable while it heals. An ordinary cold sore clears by itself in about ten days, so for a rare, mild episode, home care is reasonable.
What home care cannot do: creams barely move the needle once the blister is established, and nothing over the counter prevents recurrences. Frequent, large or slow-healing cold sores respond far better to prescription antiviral tablets, taken early or preventively. A cold sore spreading near the eye needs a doctor the same day.
The strongest at-home treatment is still a doctor. A video consultation brings one to your sofa: an honest assessment, and a prescription to a local pharmacy when treatment is right. You can see a doctor over video, usually within 15 minutes. Book a video consultation: the exact price is shown before you pay.
Are cold sores contagious?
Very, from the first tingle until the sore has fully crusted. The virus spreads by kissing, shared cutlery, glasses, towels and razors, and it can be passed to the genitals during oral sex, where it causes genital herpes.
Highest-risk window: the blister and weeping stages. Avoid kissing babies entirely while a cold sore is active; neonatal herpes is rare and serious.
Between episodes: occasional shedding without symptoms means transmission is possible but much less likely; frequent sufferers can discuss suppressive antiviral treatment with a doctor.
How long does a cold sore last?
Seven to ten days for most: tingle, blister, weeping, crust, healed. Untreated, the visible sore typically clears within about two weeks without scarring.
Shortening it: the window and the medicines that genuinely change the timeline are covered under how do you get rid of cold sores fast, and the short answer is that speed means treating at the tingle, not at the crust.
How Mobi Doctor works
- Book a time that suits you: open daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, exact price up front.
- Upload your photos, then speak to a licensed doctor: a private video call: you describe what you feel, the doctor asks what matters, and you agree the right plan together.
- Get your plan: if the doctor prescribes antivirals, you can use the prescription at a pharmacy near you; if your doctor decides you need to be seen in person, you get a full refund.
No sign-up needed
Not sure it’s a cold sore? Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Not sure this is the right page? Look up any symptom in the full symptom checker, or book and describe it to a doctor.
Frequently asked questions about cold sores
What is a cold sore, and is it herpes?
A cold sore is a cluster of small fluid-filled blisters on or around the lip caused by herpes simplex virus, usually type 1 (HSV-1), which most people catch in childhood from a kiss by someone with a sore. The virus then sleeps in the nerve supplying the lip and reactivates from time to time. Cold sores are herpes in the medical sense, but HSV-1 on the lip is not a sexually transmitted infection.
What causes cold sores to come back?
Cold sores come back when the dormant virus is reactivated by strong sunlight, a cold or flu, fever, tiredness, stress, a period, dental work or injury to the lip, or anything that lowers local immunity. Most people with recurrent cold sores get one to a few outbreaks a year, usually in the same spot, and the frequency tends to fall with age.
What are the stages of a cold sore?
A cold sore runs a recognisable five-step course: a tingling, itching or burning patch at the lip edge for a few hours to a day; a cluster of small, tense blisters; blisters bursting into a shallow weeping sore, the most contagious stage; a yellowish crust that may crack and bleed; and healed skin at around 7 to 10 days, normally without a scar.
Can an online doctor prescribe antiviral tablets for cold sores in Europe?
Yes, after a consultation. A prescription is never issued without one: the doctor confirms the cold sore and its stage by photo and video, then prescribes a short course of aciclovir or valaciclovir when tablets will help, or a standby supply to start at the next tingle. Any prescription can be used at a pharmacy near you.
How do I get rid of a cold sore fast?
No treatment removes a cold sore overnight. The fastest realistic option is an antiviral tablet started within 48 hours of the first tingle, ideally before blisters appear, which shortens healing by a day or two and softens the outbreak; antiviral creams help less. Once a cold sore is weeping or crusting, tablets add little, and gentle care plus time are what remain.
How long does a cold sore last?
An untreated cold sore lasts 7 to 10 days from the first tingle to healed skin, and the visible sore clears within about two weeks without scarring. Antiviral tablets started early shorten this by a day or two. A cold sore that lasts longer than two weeks, keeps spreading, or sits near the eye needs a doctor to look again, because it may not be a simple cold sore.
When is a cold sore no longer contagious?
A cold sore is contagious from the first tingle until every blister has crusted and the crust has fallen away leaving healed skin, usually around 7 to 10 days in; the weeping blister stage sheds the most virus. Until then: no kissing, no oral sex, no sharing lip products, cutlery, glasses, towels or razors, and hand washing after touching the sore.
Can I kiss my baby if I have a cold sore?
No, not on the face and not on the hands, until the cold sore has completely healed. Neonatal herpes is rare but can be devastating, and a fresh cold sore sheds exactly that virus. Wash hands thoroughly before handling the baby, do not share dummies or spoons, and take a newborn with blisters, fever, poor feeding or floppiness to emergency care without delay.
Why do I always get a cold sore in the sun?
Ultraviolet light suppresses local immunity in the lip and reactivates the herpes virus, which makes strong sun one of the most reliable cold sore triggers there is, on beaches and in snow alike. A high-SPF lip balm reapplied through the day prevents many of these outbreaks, and people who know the pattern can start antiviral tablets at the first tingle.
Is it a cold sore, impetigo, angular cheilitis or a spot?
A cold sore announces itself with a tingle, forms a tight cluster of blisters at the lip edge, and repeats in the same spot. Impetigo forms honey-gold crusts that spread outward and to new sites without the tingle. Angular cheilitis is a sore, cracked patch at the corner of the mouth that lingers for weeks. A spot is a single raised lump with no blister cluster.
What can I do at home for a cold sore?
Keep a cold sore clean and leave it alone: dab rather than rub, use a cold compress for throbbing, take paracetamol or ibuprofen for pain, keep it moist with petroleum jelly, and eat and drink on the other side of the mouth. A pharmacy antiviral cream helps only if started at the very first tingle; a hydrocolloid patch hides the sore and stops you touching it.
Can I take cold sore treatment in pregnancy, or if I have eczema?
In pregnancy, cold sores are common and antiviral tablets can be used when the benefit justifies it, which the doctor weighs case by case; a first-ever cold sore late in pregnancy is reviewed promptly. With eczema, the virus can spread across broken skin as eczema herpeticum, so punched-out sores spreading quickly with fever need in-person care urgently, not an online consultation.
How do I stop cold sores from coming back?
You cannot remove the herpes virus, but you can reduce cold sore outbreaks: high-SPF lip balm in strong sun, enough sleep, early treatment of illness, and a standby antiviral supply started at the first tingle. For about six or more outbreaks a year, or fewer but severe ones, daily suppressive antiviral tablets cut frequency substantially and are reviewed after 6 to 12 months.
- Herpes simplex, oral: Clinical Knowledge Summary, NICE Clinical Knowledge Summaries, revised 2024.
- Herpes simplex virus: fact sheet, World Health Organization, 2024.
- Herpes simplex, DermNet New Zealand Trust, updated 2023.
- Interventions for prevention of herpes simplex labialis (cold sores on the lips), Cochrane Database of Systematic Reviews, 2015.
- Cold sores: signs, symptoms, causes and treatments, HSE, Health Service Executive (Ireland), reviewed 2025.
- Cold sores, NHS, National Health Service (UK), accessed October 2026.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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Read article →Speak to a doctor about cold sores over video, usually within 15 minutes
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