What is acyclovir ointment for?

Acyclovir ointment is a topical antiviral used to treat infections caused by herpes simplex virus (HSV). It’s most commonly used for cold sores (herpes simplex labialis) on the lips or face. It can also be used for certain other mucocutaneous herpes infections if your clinician approves it.

How it works: It inhibits viral DNA production, helping to slow viral replication and speed healing of the lesions.

What to expect:
- Start at the first sign of an outbreak (tingling, itching, or pain) for best results.
- It’s not a cure and doesn’t prevent future outbreaks or transmission.
- It’s for external use only and should be applied as directed on the product label or by your clinician.

Common considerations:
- Use as directed (usually several times a day for a few days).
- Wash hands before and after applying; avoid eyes and mucous membranes.
- Some people may experience mild irritation at the application site.

If you’re pregnant, breastfeeding, have a weakened immune system, or are giving it to a child, or if the outbreak doesn’t improve after a few days of treatment, check with a healthcare provider. If you have an allergy to acyclovir or similar drugs, don’t use it.

If you want, tell me the brand or the label you’re using and I can summarize the exact dosing and instructions from that product.