Treating cold sores 

Cold sores usually clear up without treatment within 7 to 10 days. Antiviral tablets or cream can be used to ease your symptoms and speed up the healing time.

Antiviral creams and tablets

Antiviral creams such as aciclovir or penciclovir (also known as Fenistil) may speed up the healing time of a recurrent cold sore infection if used correctly.

Cold sore creams are widely available over the counter from pharmacies without a prescription. They are only effective if you apply them as soon as the first signs of a cold sore appear, when the herpes simplex virus is spreading and replicating. Using an antiviral cream after this initial period is unlikely to have much effect.

If you have frequently recurring bouts of cold sores, use antiviral medication as soon as you feel the tingling sensation that indicates that a cold sore is about to develop. You will need to apply the cream up to five times a day for four to five days.

Antiviral creams can only help to heal a current outbreak of cold sores. They do not get rid of the herpes simplex virus or prevent future outbreaks of cold sores occurring.

Antiviral tablets are generally more effective than creams at treating cold sores, but are usually only prescribed for more severe cases.

Cold sore patches

Cold sore patches that contain a special gel called hydrocolloid are also available. They are an effective treatment for skin wounds and are placed over the cold sore to hide the sore area while it heals.

Non-antiviral treatments

Several non-antiviral creams are also available over the counter without a prescription from pharmacies.

These creams are not specifically designed to treat cold sores and will not help them heal faster, but they may help ease any pain or irritation. Ask your pharmacist to recommend a suitable treatment for you.

Pain can also be treated with painkillers such as ibuprofen or paracetamol (both are available in liquid form for young children).

However, don't take ibuprofen if you have asthma or stomach ulcers, or you have had them in the past.

Children under the age of 16 should not take aspirin.

Speak to your GP if you have cold sores and you are pregnant.

Treating complications

If your cold sores are particularly severe or your immune system is damaged (for example, if you have HIV or you are having chemotherapy treatment), you may be at risk of developing serious complications.

For example, your risk of developing encephalitis or the infection spreading to other parts of your body, such as your eyes, is increased.

Visit your GP if you are at risk. They may prescribe antiviral tablets and refer you for specialist treatment. The type of treatment recommended will depend on the severity of your cold sore symptoms and the complication that is causing problems.

For example, if you develop herpetic keratoconjunctivitis (a secondary eye infection), you may need to see an ophthalmologist (a specialist eye doctor).

Read more about the complications of cold sores.


Also visit your GP if you or your child develops gingivostomatitis (swollen, painful gums) as a result of the primary herpes simplex infection. They will be able to suggest treatments to help ease your symptoms.

If the infection is painful, your GP may suggest using a preparation that contains benzydamine (available as an oral rinse or oral spray) to help relieve any pain in your mouth or throat.

Brushing your teeth may also be painful because of the swelling of your gums. Your GP may suggest using an antiseptic mouthwash. This will help prevent secondary infections and will also control a build-up of plaque if you cannot brush your teeth effectively.

As with the treatment of cold sores, any pain or fever can be treated using ibuprofen or paracetamol. Again, do not take ibuprofen if you have asthma or if you have stomach problems, such as stomach ulcers. Children under the age of 16 should not take aspirin.

In rare cases of gingivostomatitis, it is possible for your lips to become stuck together in places. Using a lip barrier cream, available from your local pharmacist, will help prevent this happening.

If you or your child has gingivostomatitis, it is important to drink plenty of fluids to avoid becoming dehydrated. Young children are particularly at risk as they may refuse to eat or drink because of the pain in their mouth.

It is important to watch out for signs of dehydration, such as:

  • headaches
  • tiredness
  • irritability
  • lightheadedness
  • low urine output

Most cases of gingivostomatitis will get better in 7 to 14 days, although it may take up to three weeks for the sores to heal completely.

Specialist treatment

If you or your child still has symptoms of gingivostomatitis after two weeks or the infection is severe, go back to your GP, who may refer you for specialist treatment.

Specialist referral may also be needed for gingivostomatitis if you are pregnant or have a weakened immune system.

Visit your GP if you have a newborn baby who develops gingivostomatitis, as they may also need to be referred for specialist treatment.

Cold sore advice

  • drink plenty of fluids to avoid dehydration
  • avoid acidic or salty foods and eat cool, soft foods
  • if brushing your teeth is painful, use an antiseptic mouthwash
  • dab creams onto sores rather than rubbing it in
  • wash your hands using soap and water before and after applying cold sore creams
  • avoid touching your cold sores, other than to apply cream, and don't share your cold sore cream with others

Page last reviewed: 10/04/2014

Next review due: 10/04/2016