If you are searching for the best cold sore cream, aciclovir 5% cream is a commonly available pharmacy option for adults in the UK. It is not necessarily the right choice for everyone, and treatment is generally more useful when started at the first signs of an outbreak.
Search for the best cold sore treatment and you will find confident answers pointing in both directions. Some sources say tablets clearly outperform creams. Others say the difference is negligible. Both camps are quoting real research, which is why the picture looks contradictory.
The useful version is more specific than either. Pooled trial data shows one consistent difference between oral and topical antivirals, it is smaller than most articles imply, and it is a different question from preventing the next outbreak, where the evidence separates the two routes much more sharply. That matters if you want to shorten healing time, reduce the chance that a cold sore progresses to a full ulcer, and work out whether simple outbreak treatment is enough or whether recurrent sores may justify suppressive therapy.
This guide is for UK adults looking for an effective cold sore treatment, whether you want to compare creams with tablets, choose between over the counter and prescription options, check safety and side effects, or decide what to order online. It covers what the comparison studies found, how aciclovir works, when timing and application make the biggest difference, how the various creams differ from each other, what you can buy in the UK without a prescription, and which route tends to suit which situation.
The Same Drug, Two Delivery Routes
Aciclovir is a guanosine analogue that gets switched on by a viral enzyme, thymidine kinase. This helps it act mainly in cells infected with herpes simplex virus. Once activated it blocks the viral DNA polymerase and stops the virus copying itself.
Cream puts that drug straight onto the lesion, with minimal absorption into the bloodstream. Tablets deliver it through the circulation so it reaches the lesion from the inside, along with everywhere else. The pharmacology at the infected cell is identical. What differs is how much drug reaches the site, how reliably, and what else the drug reaches on the way.
One clarification worth making, because it appears on a lot of cold sore pages including the current version of this one: aciclovir cream does not form a protective barrier over the sore. It is a vehicle carrying a drug into the skin, not a dressing. Barrier and protection are what hydrocolloid patches do, and they contain no antiviral at all.
What Happens When You Compare Them Head to Head
Both Routes Work
A systematic review and meta analysis of nucleoside antiviral drugs for herpes labialis pooled sixteen publications covering both oral and topical treatment. Its finding was that oral and topical antivirals both shortened the course of the outbreak and both reduced the likelihood of lesions progressing to the ulcerative stage. That is the starting point, and it rules out the idea that creams do nothing.
The One Difference That Reached Significance
In that same analysis, the only significant difference between the oral and topical groups was a reduction in the healing time of all lesions, favouring oral medication. So the claim that tablets work better is not invented. It has a specific and quite narrow basis: healing time, not symptom relief, not prevention of progression, not viral clearance.
How Big Is the Difference?
This is the part that usually gets lost. A separate review of oral antiviral treatment for recurrent cold sores, covering five placebo controlled and two comparative studies, concluded that oral treatment shortened lesion duration by about one day, and described that as a modest clinical implication. Independent summaries of the field describe the reduction in healing time with either systemic or topical agents as modest.
So the honest framing is this. Both routes help. Oral treatment has a measurable edge on healing time. That edge is on the order of a day against an outbreak that typically runs seven to ten days untreated, and it is not the difference between a cold sore and no cold sore.
Timing Matters More Than the Route
Antivirals only act on virus that is actively replicating. Treatment started at the first sign of a cold sore outbreak, often a tingling feeling, itching, or burning feeling before anything is visible, has far more replication left to interrupt than treatment started once the blister has formed and the immune response is well underway; if you do not start early, blisters may appear as the outbreak develops. Reviews consistently note that antiviral creams work best when used as soon as these symptoms begin, which is why timing matters so much when you want to treat cold sores.
In practice, starting treatment early may be more useful than choosing a route after the outbreak is already established. The best option depends on the person, the timing and the clinical situation.
| Question | What the pooled evidence shows |
|---|---|
| Do creams work at all? | Yes, topical antivirals shorten the outbreak and limit progression to ulceration |
| Do tablets work better? | On healing time specifically, oral treatment showed the only significant advantage in meta analysis |
| By how much? | Reviews put oral benefit at roughly one day of lesion duration, described as modest |
| Does either cure it? | No, neither reaches the dormant virus in the nerve |
| What matters most? | Starting during the tingling stage rather than after blisters appear |
| What about prevention? | A different question with a different answer, covered below |
Prevention Is a Different Question, and the Answer Differs
Treating an outbreak and reducing how often outbreaks happen are not the same intervention, and this is where the two routes genuinely separate.
A Cochrane review of interventions for preventing cold sores concluded that long term use of oral antiviral agents can prevent recurrences, while noting that the clinical benefit is small and that no increased risk of adverse events was found. On the topical side it found no evidence that short term use of topical antivirals prevented recurrence, and described the efficacy of long term topical aciclovir cream as uncertain.
Two practical conclusions follow. If your interest is fewer outbreaks rather than a shorter one, that conversation is about oral treatment, and it means a longer suppressive course rather than reaching for tablets when a sore appears. And applying cream in anticipation of an outbreak, before anything has started, is not supported by the evidence.
Suppressive treatment is a prescriber decision, based on how often and how severely you get outbreaks and on whether they are causing genuine disruption. It is not something to start on your own judgement, and the Cochrane finding that the benefit is small is worth weighing honestly before committing to months of medication.
What You Can Buy Without a Prescription in the UK
This causes more confusion than any other part of the topic, partly because the rules differ from country to country.
- Aciclovir 5% cream, 2g pack. A pharmacy medicine. You can buy it over the counter from a pharmacy after a short suitability check, with no prescription needed.
- Larger packs of aciclovir cream. Prescription only.
- Aciclovir tablets, any strength. Prescription only.
- Valaciclovir tablets, branded or generic. Prescription only.
So the answer to whether there is an over the counter treatment for oral herpes is: yes for the cream, no for anything you swallow. There is no over the counter antiviral tablet for cold sores in the UK, and any website offering to send you one without a clinical assessment is not operating within UK rules. A legitimate online pharmacy is registered with the General Pharmaceutical Council and has a prescriber review your assessment before supplying a prescription only medicine.
How the Creams Differ From Each Other
Walk along the cold sore shelf and you will see several creams at very different prices. Most of the difference is not in the medicine.
Branded Versus Generic Aciclovir Cream
Aciclovir 5% cream is sold under several brand names as well as a plain generic. They contain the same active ingredient at the same strength and are bioequivalent, meaning they deliver the drug comparably. A more expensive tube is not a stronger one. What you are paying for is the brand, the packaging and the marketing, which is the plain answer to why one aciclovir cream can cost several times what another does.
Antiviral Plus Steroid Combination Creams
This is the one genuine step forward in the topical category. A cream combining aciclovir 5% with hydrocortisone 1% targets both the viral replication and the local inflammation, on the reasoning that inflammation contributes to how bad a cold sore gets.
A meta analysis of topical corticosteroids added to antiviral therapy found that combined treatment significantly reduced the rate of ulcerative lesions compared with placebo, and also compared with antiviral treatment alone. Healing time was shorter than placebo, though not significantly different from antiviral alone. In other words, the benefit shows up as fewer sores progressing to the ulcer stage rather than as faster healing once one has formed. Availability of specific products varies, so a pharmacist is the quickest way to check what is stocked.
Products That Are Not Antivirals
| Product | Antiviral | What it actually does |
|---|---|---|
| Aciclovir 5% cream | Yes | Blocks viral replication in the treated area |
| Aciclovir with hydrocortisone cream | Yes, plus a mild steroid | Adds an anti inflammatory effect, aimed at stopping progression to an ulcer |
| Hydrocolloid cold sore patches | No | Absorbs fluid, protects and conceals the sore, reduces scabbing |
| Lip balms and barrier products | No | Keeps lips comfortable and helps reduce irritation, but has no effect on the virus |
| Herbal and propolis lip products | No | Marketed for cold sores but not licensed antivirals, with limited evidence |
| Numbing gels | No | Symptom relief only: antiseptic and soothing agents do not kill the virus, but can ease pain, help prevent cracking, and make healing feel less painful or irritating |
Why There Is No Single Best Cold Sore Treatment
It is a fair question and it deserves a straight answer rather than a product name. The evidence does not identify one treatment that outperforms the rest for everyone. What it identifies is a set of options with modest, broadly comparable effects, where the largest variable in your control is how early you start.
There is one interesting exception in the literature worth mentioning honestly. A network meta analysis ranking antiviral interventions for herpes labialis put a combination of an oral antiviral with a potent topical steroid at the top for reducing healing time. That is a research finding about combination therapy rather than a recommendation, potent steroids on the face carry their own considerations, and it is not a self treatment route. It is included here because it shows the direction the evidence points: combining mechanisms tends to do more than picking a stronger single product.
Which Route Tends to Suit Which Situation
This is a guide to the conversation with a pharmacist or prescriber, not a recommendation. Treatment suitability depends on an individual clinical assessment.
- An occasional, recognisable sore caught at the first sign or first symptoms: topical treatment is usually enough to treat it and is the easiest to get hold of (adults typically self treat with pharmacy cream, but use in children should be checked first).
- A sore that is large, spreading, or somewhere awkward to keep cream on the affected area: the oral route is more practical.
- Outbreaks several times a year that are genuinely disruptive: worth asking about a suppressive approach rather than treating each one.
- Difficulty remembering repeated applications through the day: tablets remove that problem.
- A weakened immune system, fever, or a sore that is spreading: get assessed rather than self treat.
- Pregnancy or breastfeeding: speak to a doctor, pharmacist, or other healthcare professional before use, especially if you take other medicines, rather than assuming a topical product is automatically fine.
- Existing kidney problems: relevant to oral antivirals in particular, since they are cleared by the kidneys, so raise it during your assessment.
Side Effects and Safety
Aciclovir cream is generally well tolerated, although some people may experience local irritation. The most common complaint is mild stinging, burning or dryness where it is applied. Serious reactions are uncommon, but swelling of the face or lips may be a sign of an allergic reaction and needs urgent medical attention. It is not for use inside the mouth or nose, in the eyes, or on the genitals, as conditions such as genital herpes or herpes simplex eye infections need different treatment; acyclovir ointment, not this cream, is used for simplex eye infections and some other eye infections.
Oral antivirals are also generally well tolerated, and the Cochrane prevention review found no increased risk of adverse events with long term use. Reported effects include headache, nausea, dizziness, diarrhoea and rash. Severe or unusual symptoms should be assessed promptly. Because they are cleared by the kidneys, people with kidney problems should tell their prescriber, as the dose of oral treatment may need to be adjusted. Known hypersensitivity to aciclovir or valaciclovir rules out both. Report other side effects if they are unusual or severe.
Get medical advice if a cold sore has not healed after about nine days, if outbreaks are becoming more frequent or severe, if you have a weakened immune system, or if you develop eye pain, redness or any change in vision, which needs urgent medical attention. Contact a doctor if you are concerned about side effects, if new symptoms appear, or if the infection seems to be worsening.
Treatment Options and Costs
| Treatment | Type | From |
|---|---|---|
| Aciclovir 5% Cream | Topical antiviral | £8.99 |
| Aciclovir Tablets | Oral antiviral | £12.99 |
| Valaciclovir | Oral antiviral | £18.99 |
| Valtrex | Branded valaciclovir | £34.99 |
If you would like a prescriber to review which route fits your outbreak pattern, you can complete an online cold sore assessment. Your prescriber will determine which treatment, if any, is appropriate for you.
Medical Disclaimer
This article is intended for general information and does not replace individual medical advice. It should not be used to diagnose a condition or to select a treatment without professional input. It does not contain dosing instructions; follow the leaflet supplied with your medicine and the directions given by your prescriber or pharmacist. Antiviral medicines are not suitable for everyone, and treatment suitability depends on an individual clinical assessment. Prescription medicines should only be used under the supervision of an appropriately qualified prescriber. Results vary between individuals. Seek prompt advice if you are pregnant or breastfeeding, have kidney problems or a weakened immune system, if a sore is near the eye, or if an outbreak is unusually severe or slow to heal.
