Zovirax 5% Cream

Zovirax 5% Cream is a well-known, original-brand topical antiviral cream containing aciclovir (acyclovir) 5% w/w. It is used to treat cold sores (herpes labialis), the small, painful blisters that develop on or around the lips and mouth as a result of infection with the herpes simplex virus. Zovirax works best when applied at the earliest warning signs of an outbreak — tingling, itching, burning, or redness in the usual cold sore area — ideally before a visible blister has formed.

Zovirax 5% Cream is available over the counter at DoctorOnCall for adults and adolescents who experience recurrent cold sores. It does not eliminate the herpes virus from the body, which remains dormant between outbreaks, but when applied correctly and early it can reduce the severity of symptoms, shorten the healing time, and lower the chance of the sore progressing to a full-blown blister.

Aciclovir, the active ingredient in Zovirax, is a synthetic antiviral that is taken up preferentially by cells infected with herpes simplex virus. Once inside an infected cell, it is converted into its active form and blocks the viral DNA polymerase enzyme that the virus relies on to replicate its genetic material. By halting this replication process, aciclovir limits how far the virus can spread within the skin, allowing the body’s own immune defences to clear the outbreak faster and with less severe symptoms.

Wash your hands before and after applying. Apply a thin layer of Zovirax 5% Cream to the affected area as soon as the first symptoms appear, and reapply approximately every 4 hours, around 5 times a day, for 5 to 10 days, continuing until the lesion has healed. Use a clean fingertip or cotton bud to avoid spreading the virus to other parts of the body or to other people, and do not share your tube of Zovirax with anyone else.

For adults and adolescents, apply Zovirax 5% Cream 5 times a day at roughly 4-hour intervals for 5 to 10 days, starting treatment as early as possible — ideally at the very first tingling or itching sensation, since treatment started after the blister has fully formed is less effective. If the cold sore has not healed after 10 days of consistent use, stop and consult a doctor or pharmacist.

Zovirax 5% Cream is valid for use up to the expiry date printed on the tube and outer packaging when stored correctly and unopened. Always check the expiry date before use and do not use the cream if it has expired.

Store below 30°C in a cool, dry place away from direct sunlight. Keep the tube tightly closed after each use. Do not freeze. Keep out of the reach and sight of children.

• Known hypersensitivity or allergy to aciclovir, valaciclovir, propylene glycol, or any other ingredient in Zovirax Cream
• Not for use inside the mouth, in the eyes, or on genital herpes sores without a doctor’s advice, as alternative formulations or oral treatment may be more appropriate
• Not intended for use on broken or actively weeping skin outside the typical cold sore area without medical advice
• Pregnant or breastfeeding women should consult a doctor or pharmacist before use
• Consult a doctor if cold sores are unusually frequent, severe, or occur in someone with a weakened immune system

• Topical aciclovir in Zovirax Cream has very low systemic absorption, so significant drug interactions are unlikely with normal use
• Avoid applying other lip balms, cosmetics, or creams directly onto an active cold sore at the same time as Zovirax, as this may reduce its effectiveness
• No significant food interactions are expected with topical use
• Let your pharmacist know if you are taking oral antiviral medicines for herpes, in case of any specific guidance

• Apply Zovirax at the very first tingling, itching, or burning sensation for the best results
• Use a clean fingertip or cotton bud rather than repeatedly touching the sore with bare fingers
• Avoid picking, squeezing, or scratching the cold sore, and avoid kissing or sharing drinks/utensils while it is active
• Wash your hands thoroughly after each application
• Use lip sunscreen or balm with SPF if sunlight tends to trigger your cold sores
• See a doctor if the sore does not improve within 10 days, recurs frequently, or spreads beyond the usual area

Cold sores are caused by the herpes simplex virus, which remains dormant in nerve tissue after the initial infection and can reactivate due to triggers such as stress, illness, fatigue, hormonal changes, or sun exposure. Zovirax 5% Cream treats an active outbreak but does not cure or remove the underlying virus, so cold sores can recur over time. Anyone who experiences very frequent or unusually severe outbreaks, or who has a weakened immune system, should discuss further management with a doctor.