Cold sores

Antiviral aciclovir tablets and cream for the treatment of cold sores available to buy online.

Read medical information and answer medical questions to buy treatment online.

Cold sore medication


All medicine supplied is UK licensed.

Aciclovir 200mg tablets pack

Aciclovir tablets (200mg)

25-50 tablets from £8.95

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Aciclovir 400mg

Aciclovir tablets (400mg)

Suppression from 30p/day

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Aciclovir cream pack

Aciclovir cream 5% (2gm-10gm)

Tubes from £2.75

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Treatment type Quantity Cost
Aciclovir 200mg tablets 25 tablets (one treatment) £8.95
Aciclovir 200mg tablets 50 tablets (two treatments) £13.95
Aciclovir 400mg 168 tablets (3 months suppressive treatment) £29.20
Aciclovir 400mg 336 tablets (6 months suppressive treatment) £49.40
Aciclovir cream 5% 2gm tube £2.75
Aciclovir cream 5% 4gm (2 x 2gm tube) £5.00
Aciclovir cream 5% 10gm (large tube) £9.50

Price match guarantee
Prescription issued online - small prescription fee per order.

Prescription fees

Dr Fox supplies medicine on prescription and charges a small prescription fee based on the order value of each prescription.

Prescriptions are issued by our doctors online and sent electronically to our pharmacy.

Order value Prescription fee
up to £10 £1.00
up to £20 £2.00
up to £40 £3.00
over £40 £4.00

If you have your own private or NHS paper prescription please post to our pharmacy (details).

Dr Fox prices are 25%–50% lower than other UK online clinics.

Delivery charges

UK delivery only: £2.90 per consultation via Royal Mail Tracked 24 Signed For (1-2 working days with tracking).

Parcel forwarding services are not permitted. Use only UK home or work delivery address.

Returns and refunds - unwanted items can be returned within 14 working days for a full refund.

Medical information

Written and reviewed by a team of doctors. Dr Fox is regulated by the CQC & GPhC.

What are cold sores?

Cold sores are small lumpy blisters and ulcers on the lips caused by a herpes virus - usually HSV1 (herpes simplex virus type 1), but occasionally HSV2 (herpes simplex virus type 2) which more commonly causes genital herpes. Aciclovir tablets and cream are antiviral treatments which can reduce the severity and duration of cold sores. Tablets may be a more convenient treatment than cream.

Is it a cold sore?

People who have had cold sores before usually recognise the symptoms, mainly because the sores come up in exactly the same place each time. There is often a tingling sensation for 24 to 48 hours before the redness, then blistering, then an ulcer develops.

Most cold sores usually last 7-10 days before completely healing, usually without scarring. If symptoms are not improving after a few days, or are worsening, or there is a high fever and generalised flu-like symptoms, consult a doctor.

People who have not had cold sores before, and have symptoms for the first time, should consult a doctor. The first episode may be more severe, including a sore throat or mouth and swollen lymph glands as well as the classic blistering sores on the lips.

Sores that are yellow, sticky, and crusty - and spread out over a period of a few days - are likely to be impetigo, not cold sores. Impetigo is a bacterial infection and it should be treated with antibiotics or hydrogen peroxide, not aciclovir, which is an antiviral.

Below is a photograph of a typical cold sore.

photo of a cold sore

Aciclovir cream and tablets

Aciclovir cream and aciclovir 200mg tablets are supplied by Dr Fox pharmacy to treat recurrent cold sores on the lips. Some people have cold sores which come up time and again in the same place on the lips. This is because after the first infection the virus stays living in the body and so new cold sores can break out - usually at times of stress or in response to triggers such as fatigue, cold weather, strong sun or wind exposure, or menstruation. In some cases cold sores come up without an obvious trigger. Early treatment with either aciclovir cream or tablets will usually reduce the severity and the duration of the sore.

Treatment with either tablets or cream should be started as soon as symptoms begin, preferably at the tingling stage, before a sore breaks out on the skin surface. If treatment is not started within a few days of symptoms starting, it is not likely to be effective. Aciclovir cream is also available from pharmacies and many supermarkets.

Dose of aciclovir

Treatment dose

Apply aciclovir cream or take one aciclovir 200mg tablet 5 times daily for 5 days (every 4 hours during the day time, leaving out a dose overnight). Tablets can be swallowed whole or dissolved in water - there are 25 tablets total in one course. Cream is usually continued for about the same length of time, but can be used for up to 10 days, until the sore has almost completely healed. The tablets are usually more effective than the cream.

Suppressive dose

Some patients with severe and frequent cold sores take daily aciclovir to help prevent outbreaks of cold sores. Frequent episodes are usually defined as 6 or more episodes in a year. To suppress outbreaks it is recommended to take aciclovir 400mg tablets twice a day for 6-12 months. This may reduce the number of outbreaks you have. After 12 months, stop taking the suppressive dose of aciclovir and reassess how often the cold sore outbreaks occur. If outbreaks continue again frequently, the suppression can be re-started for another few months, before trying another break. Research has shown that aciclovir can be safely continued for many years if necessary.

Please note: The dose instruction in the patient information leaflet supplied with the tablets is different from the instruction on the packet - follow the prescription instruction label on the box.

Tablets will be supplied in blank boxes of 25 or 50 tablets, except for suppressive treatment which is supplied in original medicine boxes of 56 tablets.

The dosage for cold sore treatment is different to genital herpes treatment.

Aciclovir cautions

Most people can take aciclovir tablets, even with other prescribed medication.

Do not use aciclovir if you have a known hypersensitivity/allergy to aciclovir or valaciclovir. Consult your regular doctor before using aciclovir if you have a known hypersensitivity/allergy to other antiviral drugs of the same class e.g. cidofovir, entecavir, famciclovir, ganciclovir, ribavirin, valganciclovir.

Consult a doctor before using aciclovir if taking:

  • Mycophenolate mofetil, used to stop your body rejecting transplanted organs.
  • Theophylline or aminophylline (used in asthma and other breathing problems).
  • Any medication which mentions urine or kidney problems as side effects in the patient information leaflet.

People with significantly reduced kidney function may require reduced doses of aciclovir tablets. Whilst taking aciclovir tablets, it is important to drink plenty of water to prevent dehydration.

Consult your regular doctor before taking aciclovir if you have any of the following conditions:

  • Reduced immunity e.g. after a bone marrow transplant, low white blood cell count, HIV.
  • Neurological illness.
  • Long-standing low oxygen levels.
  • Abnormal liver blood tests.
  • Blood chemistry abnormalities.
  • Age over 65.

Dr Fox cannot prescribe aciclovir if any of the above cautions apply.

Pregnancy and breastfeeding: The manufacturers of aciclovir cream and tablets advise to use with caution, as with any medication, in pregnancy and breastfeeding. This is precautionary advice, and there is no evidence of harm from aciclovir to developing pregnancies or breastfed infants. Aciclovir has been shown to pass into breast milk.

Active cold sores can pass the herpes virus to newborn infants so consult your GP or midwife if you develop cold sores in late pregnancy or whilst breastfeeding.

Side effects of aciclovir

Most people do not experience significant side effects. Of those who experience side effects the most common (affecting between 1 in 10 and 1 in 100) are dizziness and headache or nausea, vomiting, diarrhoea and abdominal pain, fatigue and fever, skin reactions, or photosensitivity.

People who are affected by drowsiness should not drive or operate machinery.

A full list of cautions and side effects can be found in the manufacturer's patient information leaflets:

Other measures to help with cold sores

  • Pain can be helped by paracetamol or ibuprofen.
  • Mouthwash, and anaesthetic gels may help with pain from lesions inside the mouth.
  • Lip barrier gels may be soothing.
  • Cold sore patches may help with healing, disguise the sore and also provide a barrier to reduce risk of spread.

If cold sores are not improving after 5-7 days or you are seriously unwell with them, consult your regular doctor.

There are devices on the market which offer heat or near-infra-red light therapy for cold sores. Both types of product have been shown in manufacturers' trials to be effective at reducing symptoms and overall healing times.

How to prevent passing the virus to others

Active cold sores shed herpes virus. They are sometimes called a 'kissing disease' as the virus from an active cold sore is easily passed on by any close contact with other people. When you have a cold sore, it is therefore very important to avoid intimate contact and also to avoid sharing towels, flannels, and other items such as lipstick, lip balm, and lip gloss. Wash your hands with soap and water after touching the cold sore and be careful not to transfer the virus to your eyes especially if you wear contact lenses.

Delay dental treatment until lesions have healed.

Cold sores and genital herpes

Cold sores and genital herpes infections are caused by similar types of herpes viruses - HSV1 and HSV2. Because of this, a cold sore infection can spread by direct contact from the lips to the genital region, or vice versa. The cold sore virus can also be spread from the lip region of one person to the lip region of another and from the genital region of one person to the genital region of another. Kissing and any oral sex should be avoided when there is an active cold sore.

Buy treatment

Dr Fox supplies cold sore medication on prescription - you are required to answer a short medical questionnaire before your order can be completed.

Dr Tony Steele

Authored 18 February 2015 by Dr Tony Steele
MB ChB Sheffield University 1983. Former hospital doctor and GP. GMC no. 2825328

Reviewed by Dr A. Wood, Dr C. Pugh, Dr B. Babor
Last reviewed 06 September 2023
Last updated 19 January 2024
Editorial policy


  1. Medical questions
  2. Choose treatment
  3. Complete order

Answer medical questions to order(cold sore treatment)

Honest & accurate responses are necessary for safe medical assessment

Are you ordering treatment for cold sores and have you read the medical information?

See cold sore medical information.

Are you planning to use aciclovir whilst pregnant or breastfeeding?

Have you been diagnosed with any of the following?

  • Reduced immunity e.g. after a bone marrow transplant, low white blood cell count, HIV.
  • Neurological illness.
  • Long-standing low oxygen levels.
  • Abnormal liver blood tests.
  • Blood chemistry abnormalities.

Have you been diagnosed with severe kidney disease?

Includes conditions which could reduce kidney function - does not include occasional urinary infections. Kidney disease can be part of the ageing process and people over 65 should check with their GP.

Are you taking any of the following?

The following medicines interact with aciclovir:

  • Mycophenolate mofetil (used to stop your body rejecting transplanted organs).
  • Theophylline or aminophylline (used in asthma and other breathing problems).
  • Any medication which mentions urine or kidney problems as side effects in the medicine's patient information leaflet.

Are you aware aciclovir cream is not for internal use or for use in or around the eye?

Not for use in the vagina, anus, or inside the mouth.

Are you aware you should seek medical advice if sores are getting worse or are not healing after 10 days?

Confirm you understand the treatment doses for cold sores with aciclovir tablets:

  • Single outbreak: one aciclovir 200mg tablet five times daily for five days.
  • Suppressive therapy: One aciclovir 400mg tablet twice daily for up to 12 months.
  • Note: The prescribed dose written on the label affixed to the packet may differ from the patient information leaflet supplied with the tablets. Please follow the instruction on the label affixed to the packet supplied.

Have you had a cold sore outbreak when taking suppressive treatment (aciclovir 400mg twice daily)?

If this is your first time ordering OR if you are ordering treatment for a single outbreak, answer 'No'.

Do you have any further medical information or questions?

Is there anything you do not understand or do you need further help?

Do the following apply to you?

  • The medication is for my own use and I will not share with anyone else
  • I will read the information leaflet supplied with the medication
  • I am over 18 and I agree to identity verification checks
  • I have completed this questionnaire myself and fully understand all the information
  • My responses are honest and accurate, and I understand that this is necessary for a safe medical assessment
  • I agree to the terms & conditions, privacy policy, data sharing policy & consent to cookies

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