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Cold sores: common causes and how to treat them fast
Written byEmily Coates
Reviewed byHeeral Tomlinson
Tired of cold sores ruining your plans? With insights from a pharmacist and our handpicked product recommendations, you can be prepared when they strike
Our top picks
5% aciclovir
Zovirax
Zovirax Pump Cold Sore Cream 2g
£7.50
Hydrocolloid gel technology
Compeed
Compeed Cold Sore Discreet Healing Patch
£6.69
Controls infection
Cymex
Cymex Cream 2g
18+
£3.00
Too many of us know that feeling – just when you’ve got a big meeting or a night out, here comes that dreaded cold sore. So, what causes them, are they actually contagious and how can you get rid of them fast?
Let’s explore everything from symptoms to treatments, plus advice from expert Angeli and the products you need to keep them at bay – or at least make them less of a pain when they do show up.
What’s a cold sore?
If you’ve ever had one, you know cold sores are small, pesky blisters that pop up around your lips. But what are they really? According to Angeli: “Cold sores are small, fluid-filled blisters, caused by the herpes simplex virus (HSV) and are quite common."
"In fact, around 7 in 10 people in the UK carry the HSV virus"
Yep, that’s right – cold sores are actually caused by a virus, and once you’ve got it, it stays with you for life. But don’t panic: while they can feel like a major nuisance, they usually clear up pretty quickly. In fact, around seven in 10 people in the UK carry the HSV virus, though not everyone will have visible outbreaks.1
So, while they may be common, they’re also totally manageable. Let’s take a look at how you can stop cold sore symptoms in their tracks.
What are the symptoms of a cold sore?
“A cold sore often begins with a tingling, itching or burning sensation. Within 48 hours, one or more painful blisters may appear on the face,” Angeli says. “These blisters are typically small and contain fluid. They eventually burst, forming a scab as they begin to heal,” she adds. This process usually takes about seven to 10 days, but it can be longer depending on how quickly you treat the sore and how your body responds.”
The symptoms can sometimes feel like a right nuisance but knowing what’s coming and having the right products on hand can make a big difference.
“The earlier you treat it, the quicker it will heal”
Are cold sores contagious?
Yep, hold the kissing because cold sores are contagious. “They can spread from the first sign of tingling until they are fully healed,” explains Angeli. “The virus can easily be passed to other people or to different areas of the body”.1
So, it’s crucial to avoid sharing towels, lip balms or utensils during an outbreak. The virus can also spread through kissing or oral sex, so it's best to take precautions until the sore has completely healed. Even if you don’t have visible symptoms, the virus can still be passed on, so it’s important to stay mindful of when you might be contagious.
If you do catch a cold sore there are ways to manage it. Angeli recommends starting treatment as soon as you feel that tingling sensation. "The earlier you treat it, the quicker it will heal," she assures.1
Here are a few simple tips to help:
- use sun protection: if UV light triggers your cold sores, always apply a lip balm with SPF 15 or higher when heading outdoors.2
- stay hydrated: drinking plenty of fluids can keep your skin hydrated and promote faster healing3
- speak to a pharmacist: over-the-counter anti-viral creams can help reduce pain, swelling and speed up the healing process1
- many effective cold sore creams contain acyclovir, a proven antiviral that helps stop the virus in its tracks and supports faster healing4
I’ve heard lysine could help – is it true?
Lysine, an amino acid also known as L-lysine monohydrochloride, has been explored for its potential to help manage and prevent cold sores. "Some research suggests that taking lysine could reduce the risk of developing cold sores and help them heal faster, but the studies have been poor quality and better data is needed to confirm – so for now the jury is out," says Angeli.5,6
A 2015 review of clinical trials also found limited high-quality data and couldn’t confirm a clear benefit for cold sore prevention, so more robust research is still needed.5
You can find lysine in both supplement form and topical creams, making it an easy addition to your cold sore care routine. If you’d like to give it a try, it’s best to have a quick chat with your pharmacist first – especially if you tend to get cold sores regularly or are taking other medication.
Our cold sore products
Cold sore bothering you? Our over-the-counter range is here to help. From fast-acting antiviral creams to lip patches that heal and soothe, we’ve handpicked some products that work hard so you can get on with your day.
Zovirax Pump Cold Sore Cream is a well-known bathroom staple for treating cold sores caused by the herpes simplex virus (HSV). With clinically proven 5% aciclovir, it helps fight the virus and speeds up healing so you can get back to feeling your best.
If you prefer something a little easier to dispense, the same trusted formula also comes in a handy pump format – giving you all the benefits of Zovirax in a mess-free application. Always read label before use.
Compeed® Cold Sore Discreet Healing Patch helps seal cold sore blisters hygienically with its hydrocolloid gel technology, while protecting against the spread of the virus. The patch soothes itching and burning, prevents scabs from forming and supports faster healing, all in a discreet, easy-to-use format for adults and children. Always read label before use.
When to seek medical advice
In some cases, a cold sore might need more attention. Angeli recommends seeing your GP if:
- it’s been 10 days without healing1
- you have painful, swollen gums: if you develop sores inside your mouth, this could signal a more serious issue, and you’ll want to get it checked out7
- you’re worried it’s something else: if you’re unsure whether it’s a cold sore or another skin condition, your doctor can help with the diagnosis1
- it’s unusually large or painful: if the cold sore is causing significant pain or spreading beyond the usual area, get professional advice1
- your immune system is weakened: if you have a weakened immune system, such as from medication or a medical condition, you’ll need to take extra care to avoid complications1
The final say
Cold sores are a common but manageable part of life for many people. While they can feel frustrating, knowing how to spot the symptoms early and having the right treatments can make a big difference.
It’s always best to be proactive with cold sores, so why not stock up your first aid kit with our over-the-counter essentials (yes, we’ve got you covered). If you’re unsure about anything, don’t hesitate to speak to your pharmacist or GP – they’re there to help.
Want to help lowering stress levels? Unwind with our relaxing product picks and top supplements to support your wellbeing from the inside out.
Disclaimer - This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
1. National Health Service. Cold sores. [Internet]. London: NHS; 2023. Available from: https://www.nhs.uk/conditions/cold-sores/
2. British Skin Foundation. Sun protection for cold sore sufferers. [Internet]. London: British Skin Foundation; 2022. Available from: https://www.britishskinfoundation.org.uk/
3. Ousey K, Cutting KF, Rogers AA, Rippon MG. The importance of hydration in wound healing: reinvigorating the clinical perspective. J Wound Care. 2016 Mar;25(3):122, 124-30. doi:10.12968/jowc.2016.25.3.122. PMID: 26947692
4. Whitley RJ, Roizman B. Herpes Simplex Virus Infections. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. Available from:https://www.ncbi.nlm.nih.gov/books/NBK542180/
5. Mailoo VJ, Rampes S. Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence. Integr Med (Encinitas). 2017;16(3):42–46. PMID: 30881246; PMCID: PMC6419779. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419779/
6. Patel K. Lysine. Examine.com; 2022. Available from: https://examine.com/supplements/lysine/research/
7. National Health Service. Gums and mouth sores: when to see a doctor. [Internet]. London: NHS; 2023. Available from: https://www.nhs.uk/conditions/mouth-ulcers/
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