What is a Patient Information Leaflet and why is it useful?

The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine. It is written for patients and gives information about taking or using a medicine. It is possible that the leaflet in your medicine pack may differ from this version because it may have been updated since your medicine was packaged.

Below is a text only representation of the Patient Information Leaflet. The original leaflet can be viewed using the link above.

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on 0800 198 5000. The product code(s) for this leaflet is: PL20417/0094 .

Boots Antiviral Cold Sore Cream

Information for the user

Boots Antiviral Cold Sore Cream


Read all of this leaflet carefully because it contains important information for you.

This medicine is available without prescription to treat minor conditions. However, you still need to use it carefully to get the best results from it.

  • Keep this leaflet, you may need to read it again
  • Ask your pharmacist if you need more information or advice
  • You must contact a pharmacist or doctor if your symptoms worsen or do not improve after 10 days

What this medicine is for

This medicine contains Aciclovir which belongs to a group of medicines called antivirals, which act to treat infections caused by viruses.

It can be used to treat cold sores of the lips and face.

Before you use this medicine

This medicine can be used by adults and children. However, some people should not use this medicine or should seek the advice of their pharmacist or doctor first.

Do not use:

  • If you are allergic to aciclovir, valaciclovir or any of the ingredients in this medicine (see “What is in this medicine”)
  • To treat herpes infections (which may appear as ulcers or blisters) on your eye or in the genital area

Talk to your pharmacist or doctor:

  • If you suffer from problems with your immune system which may make you more prone to infections (this problem may be caused by an illness, some medicines or radiotherapy)
  • If your cold sore is severe
  • If you are in any doubt whether the sore is a cold sore
  • If you are pregnant, planning to become pregnant or breastfeeding

Other important information

Cold sores are infectious and you should try not to pass the infection on to other people.

Taking the following precautions may help to reduce the risk of passing on the infection:

  • Do not touch the cold sore with your hands or towel, if possible
  • Wash your hands immediately if you do touch the cold sore
  • Do not share your towels with other people
  • Do not share eating or drinking utensils with other people
  • Try not to kiss other people, especially children, until your cold sore has healed

Information about some of the ingredients: Propylene glycol in this medicine may cause skin irritation.

Cetyl alcohol may cause skin reactions (e.g. contact dermatitis).

If you take other medicines

This medicine is not expected to affect any other medicines that you may be using.

If you are unsure about interactions with any medicines, talk to your pharmacist. This includes medicines prescribed by your doctor and medicine you have bought for yourself, including herbal and homeopathic remedies.

How to use this medicine

Wash your hands before and after using the cream.

You should not mix the cream with anything before you use it, not even water.

For adults and children:

  • Apply a thin layer on the affected area making sure the whole cold sore is covered.
  • Use every 4 hours, 5 times a day, for 5 days.

If after 5 days the cold sore has not healed you can continue to apply the cream for a further 5 days if necessary.

For use on the skin only.

Apply only to the lips and face. Do not apply the cream to the inside of the mouth, the eyes or inside the vagina as it may cause irritation.

Do not use more than the amount recommended above.

If your cold sore has not healed after 10 days stop using the cream and talk to your doctor.

If your symptoms worsen at any time stop using the cream and talk to your doctor.

Do not use a double application to make up for a forgotten dose.

If anyone accidentally swallows some of the medicine: Talk to a pharmacist or doctor.

Possible side effects

Most people will not have problems, but some may get some. If you have any unwanted side effects you should seek advice from your doctor, pharmacist or other healthcare professional.

If you get any of these serious side effects, stop using the cream. See a doctor at once:

  • Difficulty in breathing, swelling of the face, neck, tongue or throat (severe allergic reactions)

If you get any of the following side effects, see your pharmacist or doctor:

Uncommon side effects:

(May affect up to 1 in every 100 people are affected)

  • Burning or stinging sensation of the skin where the cream has been applied
  • Itching, dryness or flaking of the skin

Rare side effects:

(May affect up to 1 in every 1000 people are affected)

  • Flushed skin, contact dermatitis (redness and swelling of the skin)

Very rare:

(May affect up to 1 in every 10,000 people are affected)

  • Raised, red, itchy skin (symptoms of urticaria, which is often known as hives or nettle rash)

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard

By reporting side effects you can help provide more information on the safety of this medicine.

How to store this medicine

Do not store above 25°C.

Do not freeze or refrigerate.

Keep this medicine in a safe place out of the sight and reach of children, preferably in a locked cupboard.

Use by the date on the end flap of the carton. Throw away any medicine left 6 weeks after you first open the cream.

What is in this medicine

Each gram of cream contains Aciclovir 50 mg, which is the active ingredient.

As well as the active ingredient, the cream also contains PEG-5-glycerol-stearate, dimeticone, cetyl alcohol, liquid paraffin, white soft paraffin, propylene glycol and purified water.

The pack contains 2 g of cream.

Who makes this medicine

Manufactured for

The Boots Company PLC


Laleham Health and Beauty Ltd
Sycamore Park
Mill Lane
GU34 2PR

Marketing Authorisation held by

Kent Pharma UK Limited
The Bower
4 Roundwood Avenue
Stockley Park
UB11 1AF
United Kingdom

Leaflet prepared December 2019

If you would like any further information about this medicine, please contact

The Boots Company PLC

Artwork reference: WBAG411807