Cold Sore Treatment
Get doctor-prescribed cold sore treatment delivered free to your door, or collect from your local Asda Pharmacy.
Prices from £18.00
One of our doctors will review your order and prescribe a treatment if suitable. How to Order
If cold sores are causing you discomfort, our service allows you to get a prescription for treatment, quickly and easily. We can also provide cold sore test kits if you are unsure whether you have cold sores.
Not sure whether you should buy an over the counter treatment or get a prescribed medicine? Keep reading to find out what causes cold sores and the different treatments available.
Why choose us?
- Get the most suitable treatment for you
- Your questionnaire is reviewed by one of our qualified doctors
- Order your treatment directly with us
- Choose free delivery to your address or collect from your local Asda Pharmacy
Cold sore treatments and test kits
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About test kits and treatments for cold sores
What causes cold sores?
Cold sores are common. They are small blisters that appear on the mouth and lips, caused by the virus, herpes simplex virus type 1 (HSV-1). Around 70% of people carry the virus that causes cold sores. Many are unaware they have it because they have no symptoms.
Cold sores can be easily passed on by coming in contact with someone who has them. They can be passed on with any skin to skin contact.
When you are first infected with the virus, you often will not have any symptoms. The first signs of a cold sore are tingling, itching, or burning feelings where the blister is starting to come through. Cold sores are contagious from when you first feel the tingling sensation until it has completely healed.
Sometimes, cold sores can be caused by the herpes simplex virus type 2 (HSV-2). This type of the virus is passed on by having sex with someone who has genital herpes. Genital herpes is a sexually transmitted infection (STI). It can be spread from the genitals to the mouth during oral sex.
There are two cold sore treatment options that we provide. They are aciclovir and valaciclovir. They both belong to a group of medicines called antivirals. Aciclovir and valaciclovir work by killing or stopping the growth of the viruses that cause cold sores.
- Aciclovir dose: one 400mg tablet taken 3 times a day for 5 days
- Valaciclovir dose: one 500mg tablet taken twice a day for 5 days
You should start taking aciclovir or valaciclovir as soon as you start to feel any symptoms, like tingling before the sore appears. The earlier you can start taking it, the better it will work.
Both aciclovir and valaciclovir work in the same way except aciclovir is already in its active form when you take it. That means it does not need to go through any changes in the body to start working.
Both aciclovir and valaciclovir can also be used as a daily ‘suppression’ dose when you do not have a cold sore, to stop them from happening. This can help if you have more than 6 outbreaks of cold sores in a year, or if your outbreaks are very severe.
Yes, there are antiviral creams available over the counter which contain aciclovir. These creams help your sores to heal quicker and fight the virus. If you get cold sores regularly, these over the counter treatments will not help to suppress the virus. Over the counter antiviral creams may also not work after the blisters have appeared.
By using our service, you will be provided with doctor approved and prescribed treatment. These tablets work even after a cold sore blister has appeared. They also help to stop future outbreaks.
Just like all medicines, cold sore treatment can cause side effects but not everyone will get them.
Some common side effects of cold sore treatments are:
- feeling or being sick
- skin reaction when exposed to light
- stomach pains
- unexplained high temperature and feeling faint
Less common side effects include:
- hair loss
- itchy, hive-like rash
Rare side effects include:
- effects on blood and urine tests
- fits (seizures)
- increased liver enzymes
- slow, slurred speech
- unsteadiness when walking
You should let your doctor know if you get any of these side effects.
If you get symptoms of an allergic reaction you should call 999 or a doctor right away.
This can include:
- swelling of the lips, face, neck, or throat
- difficulty breathing
- flushing, itchy skin
- low blood pressure causing collapse
You should tell your doctor if you have recently taken or might take other medicines, including over the counter and herbal medicines.
You should not use cold sore treatment if you:
- are allergic to valaciclovir, aciclovir, or any other ingredients in the medicine
- have ever had an extended rash as well as a fever, enlarged lymph nodes, eosinophilia, or high liver enzymes after using cold sore treatments
You should also let your doctor know if you have kidney problems. You should speak to your doctor before using cold sore treatments if you think you might be pregnant, are pregnant, are planning on having a baby, or currently breastfeeding.
While you have cold sores, they are highly contagious which means you can pass them onto someone else easily.
To help stop the spread of cold sores you should avoid:
- touching cold sores
- sharing medication especially antiviral creams
- kissing and oral sex
Cold sores often occur when your immune system is weak. So, looking after your health and wellbeing will help to prevent future outbreaks. It is also useful to work out what may be triggering your cold sores, so you can help to prevent them in the future.
Some common triggers include:
- a high temperature
- feeling tired
- an infection
- injury to the lips or mouth
- exposure to sunlight
Things you can do yourself to help treat a cold sore include the following:
- taking paracetamol or ibuprofen to help with the pain and swelling
- drinking plenty of fluid to stop dehydration
- avoiding your cold sore triggers
- using sunblock lip balm if you are in the sun (SPF 15 or above)
- washing your hands with warm, soapy water after applying cream to your cold sore
Dr Kathryn Basford
Dr Kathryn Basford is a qualified GP who works as a GP in London, as well as with ZAVA. She graduated from the University of Manchester and completed her GP training through Whipps Cross Hospital in London.Meet our doctors
Article created: 01 Sep 2021
Last reviewed: 01 Sep 2021
Aciclovir 400mg tablets: patient information leaflet (2019) EMC [accessed 05 August 2021]
Cold sores (2020) NHS [accessed 05 August 2021]
Cold sore symptoms and treatment (2021) NHS [accessed 05 August 2021]
Genital herpes (2017) CDC [accessed 05 August 2021]
Valaciclovir 500mg film-coated tablets: patient information leaflet (2020) EMC [accessed 05 August 2021]