Product Name
Zovirax Cream 5% 2g/Tube
Active Ingredient
Acyclovir 5%
Manufacturer
GlaxoSmithKline
Product Type
Antiviral
Product expiry date we are currently shipping
Mar 2026
Zovirax cream general information
What is Zovirax cream used for?
Zovirax cold sore cream is used to treat cold sores of the lips and face which are caused by infection with Herpes Simplex virus. A tingling sensation on the lips or face is the warning sign the virus has been activated, and if used at this early stage, within 24 hours of the first tingle, Zovirax cold sore cream may prevent the cold sore from developing. Once the cold sore has developed, it will form a blister on the skin and these blisters will join up to form a weeping sore, which is when the infection is contagious and can spread to give you more cold sores or can infect others you are in direct contact with. Eventually your immune system will kick in to kill the virus and the cold sore will form a scab as it heals. Zovirax cold sore cream can be used at any stage of infection, to prevent spread of infection, reduce and relieve painful symptoms, and speed up the heeling process to help heal blisters and sores caused by the infection. However, Zovirax cold sore cream cannot cure the infection, because once you have been infected, through a mucus membrane such as the mouth, the virus can persist undetected by travelling down a nerve fibre and lying dormant or inactive in a nerve cell, to be reactivated, for example by stress, sunlight or if your immune system is compromised.
How does Zovirax cream work?
Zovirax cold sore cream contains acyclovir, an antiviral agent which is highly active against the virus that causes cold sores; Herpes Simplex virus (HSV-I). Acyclovir in Zovirax cold sore cream inhibits the action of a viral enzyme (DNA polymerase), blocking viral DNA synthesis without affecting normal cellular processes in your infected skin cells. This prevents the virus replicating and therefore stops the growth and spread of the virus, relieving symptoms of the infection and helping the body to fight off the infection. Zovirax cold sore cream only works on virus that is rapidly growing, such as during the formation of a cold sore in the skin, but once the virus is dormant and inactive in a nerve cell, acyclovir has no effect. That is why it is important to use Zovirax cold sore cream as soon as you become aware that a cold sore may be developing (the tingle sensation) as this is when acyclovir can kill the virus and prevent it replicating in your skin cells, which is what causes the cold sore.
What does Zovirax cream contain?
Zovirax cold sore cream contains the active ingredient acyclovir 5%, an antiviral medication that is used to treat cold sores. It also contains poloxamer 407, white soft paraffin, cetostearyl alcohol (or emulsifying wax), liquid paraffin, dimethicone, sodium lauryl sulphate (or emulsifying wax), propylene glycol, purified water. Each tube of Zovirax cold sore cream contains 100mg acyclovir equivalent to 5%w/w in a water miscible base.
Treating cold sores with Zovirax cream
Zovirax cold sore cream contains acyclovir, an antiviral agent which is highly active against the virus that causes cold sores; Herpes Simplex virus (HSV-I) and is used to treat and prevent cold sores of the lips and face, which are caused by infection with HSV-1. Acyclovir in Zovirax cold sore cream blocks viral DNA synthesis without affecting normal cellular processes in your infected skin cells, which prevents the virus replicating and stops the growth and spread of the virus. A tingling sensation on the lips or face is the warning sign the virus has been activated, and if used at this early stage, within 24 hours of the first tingle, Zovirax cold sore cream may prevent the cold sore from developing. Once the cold sore has developed, it will form a blister on the skin and these blisters will join up to form a weeping sore which is when the infection is contagious and can spread to give you more cold sores or can infect others you are in direct contact with. Eventually your immune system will kick in to kill the virus and the cold sore will form a scab as it heals. Zovirax cold sore cream can be used at any stage of infection, to prevent spread of infection, reduce and relieve painful symptoms, and speed up the heeling process to help heal blisters and sores caused by the infection and help the your immune system to fight off the infection. However, Zovirax cold sore cream cannot cure the infection, because once you have been infected, through a mucus membrane such as the mouth, the virus can persist undetected by travelling down a nerve fibre and lying dormant or inactive in a nerve cell, to be reactivated, for example by stress, sunlight or if your immune system is compromised.
What are the side effects of Zovirax cream?
The most commonly reported side effects using Zovirax cold sore cream include: temporary burning, stinging, itching, redness, drying and flaking at the area where it is applied. Contact dermatitis has been reported rarely following application, usually in response to the components of the cream base rather than acyclovir.
When should Zovirax cream not be used?
You should not use Zovirax cream if you:
- are allergic to acyclovir or any components in Zovirax cold sore cream
- are pregnant or breastfeeding
- are immunocompromised, for example, due to HIV infection, or bone marrow or organ transplant
How should Zovirax cream be used?
You should apply Zovirax cold sore cream five times daily at approximately four hourly intervals, by gently rubbing a small amount onto the affected area. You should avoid contact with the eyes and inside the mouth and Zovirax cold sore cream must not be used to treat genital herpes. You should start to use Zovirax cold sore cream as soon as you feel the first tingling or burning sensation on your face or lips, but you can use it at any stage of infection and should continue to use it for 5 days to achieve complete healing. Your doctor may recommend a further course of 5 days if the cold sores have not healed.
How long should you take Zovirax cream?
You should use your Zovirax cold sore cream for as long as recommended by your doctor or pharmacist, usually for 5 days to achieve complete healing. Your doctor may recommend a further course of 5 days if the cold sores have not healed.
Missed dose of Zovirax cream
If you miss an application of Zovirax cream apply it as soon as you remember, unless it is time for the next application, then skip the missed one. Do not apply a double dose.
How should Zovirax cream be stored?
You should store your Zovirax cold sore cream in a cool, dry place at room temperature and below 25°.