A cold-sore cream for herpes labialis
Docosanol
An over-the-counter cream that helps treat cold sores on the lips when applied at the first sign of tingling.
What is Docosanol?
Docosanol is a cream used to treat cold sores, the small blisters caused by the herpes simplex virus that appear on or around the lips. It works best when applied at the very first sign of a cold sore, often a tingling, itching or burning feeling, before the blister fully forms. A thin layer is applied to the affected area on the lips several times a day until it heals, following the instructions on the pack. It is for use on the lips and the skin around them only, and should be kept away from the inside of the mouth and the eyes. It can help a cold sore heal a little faster and ease discomfort, but it does not cure the underlying virus.
Education and reference only. This is a plain-language guide to Docosanol — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Docosanol is the active ingredient in some over-the-counter cold-sore creams, such as Abreva. It is used to treat cold sores caused by the herpes simplex virus, which lives in the body and can flare up from time to time as blisters on or around the lips. Unlike some other cold-sore treatments that act directly on the virus, docosanol works on the skin cells to make it harder for the virus to take hold. It is available without a prescription and is chosen by people who want to shorten the discomfort of a recurring cold sore and help it heal more quickly.
How it works
Docosanol works on the surface of the skin cells around the cold sore. It is thought to make it harder for the herpes simplex virus to fuse with and enter healthy skin cells, which slows the spread of the virus to new cells and gives the area a better chance to heal. Because it acts at the cell surface where it is applied, it works best when started very early, at the first tingling or itching, before the cold sore has had a chance to develop fully. It treats the current outbreak rather than removing the virus, which stays in the body and can flare up again in the future.
Company & origin
Originated / developed by: Various (widely available).
An over-the-counter cold-sore cream used to treat the cold sores caused by the herpes simplex virus on and around the lips.
Practical use
How to take Docosanol
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Apply it at the very first sign of a cold sore, such as tingling, itching or burning, for the best effect.
- Put a thin layer on the cold sore and the surrounding skin, as directed on the pack.
- Continue using it until the cold sore has healed, following the pack instructions.
- Wash your hands before and after applying it, and avoid touching your eyes.
- Use it on the lips and surrounding skin only, not inside the mouth or in the eyes.
Weighing it up
Advantages & disadvantages of Docosanol
Advantages
- Can help a cold sore heal a little faster and ease discomfort when started early.
- Available without a prescription for treating recurring cold sores at home.
- Acts at the site of the cold sore on the lips rather than throughout the body.
Disadvantages
- Works best only if applied at the very first tingle, before the blister forms.
- Treats the current outbreak but does not cure the underlying virus.
- For use on the lips only, not inside the mouth, nose or near the eyes.
Practical use
Good to know
Docosanol works best when it is applied as soon as you feel a cold sore starting, usually a tingle, itch or burning feeling on the lip, rather than waiting for the blister to appear. A thin layer is applied to the cold sore and the surrounding skin and continued until it heals, as directed on the pack. It is for the lips and the skin around them only, and should not be put inside the mouth, in the nose or near the eyes. Cold sores are contagious, so it helps to wash your hands before and after applying it and to avoid sharing things like lip balms, cups or towels. If cold sores are very frequent, very severe, slow to heal, or spread to the eye, it is worth seeing a pharmacist or GP, who can advise on other treatments.
Who should not take it / use with caution
- People who have had an allergic reaction to docosanol or the cream's ingredients should not use it.
- It should not be used inside the mouth or nose, or in or near the eyes.
- Anyone with a cold sore that spreads to the eye should seek medical advice rather than self-treat.
Monitoring
- No routine monitoring is needed for ordinary cold-sore use.
- Checking that the cold sore is healing rather than spreading or worsening.
- Seeking advice if cold sores are very frequent, severe or reach the eye.
Side effects
- Mild irritation, dryness or redness where the cream is applied.
- Occasionally a headache reported around the area of use.
- Rarely, an allergic reaction needing medical attention.
Key interactions
- Avoid applying other lip creams or cosmetics on top of it at the same time unless advised.
- It is not known to interact with medicines taken by mouth in any important way.
- Tell the pharmacist about any other treatments you are using on your lips.
Available as: A cream applied to the lips and the skin around them.
Answers
Docosanol: frequently asked questions
What is docosanol used for?
It is a cream used to treat cold sores, the blisters caused by the herpes simplex virus that appear on or around the lips.
When should I start using it?
It works best when applied at the very first sign of a cold sore, such as tingling, itching or burning, before the blister has fully formed.
Does it cure cold sores for good?
No. It treats the current outbreak and can help it heal faster, but the virus stays in the body and can cause cold sores again in the future.
Can I use it inside my mouth?
No. It is for the lips and the skin around them only. It should not be put inside the mouth or nose, or near the eyes.
When should I see a doctor?
See a pharmacist or GP if your cold sores are very frequent or severe, are slow to heal, or if a cold sore spreads to your eye.
Authoritative sources
- BNF
- NICE CKS
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