Mupirocin ointment is applied in a thin layer to the affected skin area three times daily, typically for up to 10 days. It’s a prescription antibiotic ointment used to treat bacterial skin infections like impetigo, and there’s also a nasal formulation for clearing staph bacteria from the nostrils. Getting the technique right helps the medicine work effectively and reduces the chance of bacterial resistance.
Cleaning the Area Before Application
Wash your hands thoroughly with soap and water before touching the tube or the infected skin. Then gently clean the affected area with mild soap and warm water, and pat it dry with a clean towel. You want the skin free of dirt, dried drainage, or leftover ointment from the previous application. Starting with clean, dry skin helps the ointment make direct contact with the infection.
How Much to Apply
You need less than you might think. A small ribbon of ointment, roughly the size of a match head, is enough for a typical wound or sore. For larger areas, a useful guide is the “fingertip unit,” which is the amount of ointment squeezed from the tube along the length of your fingertip, from the tip to the first crease. For an adult, that fingertip unit equals about half a gram and covers roughly the area of one hand (front and back).
If your infection covers a bigger patch of skin, scale up proportionally. One arm takes about three fingertip units, one foot about two, and the face and neck together about two and a half. The goal is a thin, even layer, not a thick glob that sits on top of the skin.
Applying to Skin Infections
You can apply the ointment with a clean cotton swab, a small gauze pad, or a clean fingertip. Spread it gently over the entire infected area in a thin, even layer. Don’t rub it in aggressively, especially if the skin is raw or broken. Once applied, you can cover the area with a gauze dressing if you want to protect it from friction or keep the ointment from rubbing off on clothing. Covering isn’t required, but it can be practical for areas that get bumped during the day.
Wash your hands again immediately after applying. This prevents you from accidentally spreading the infection to other parts of your body or to someone else.
Applying Inside the Nose
The nasal formulation comes in single-use tubes and follows a different process. Wash your hands, then squeeze about half the tube’s contents directly into one nostril and the other half into the other nostril. You don’t need a swab for this; the tube tip works fine.
Once both nostrils have ointment, press the sides of your nose together, then release. Repeat this squeezing motion for about one minute. You can also gently massage the outside of your nose to help spread the ointment across the inner surfaces. Throw the tube away after each use, even if it looks like there’s ointment left. Wash your hands again when you’re done.
Frequency and Duration
The standard schedule is three times a day, spaced roughly evenly throughout your waking hours. A practical rhythm is morning, afternoon, and evening. Continue for the full course your prescriber specified, which is commonly 5 to 10 days depending on the infection.
If you miss a dose, apply it as soon as you remember. If it’s almost time for the next application, skip the missed one and continue on your regular schedule. Don’t double up to compensate.
Finishing the entire course matters. Stopping early because the skin looks better can leave surviving bacteria behind, and those survivors are more likely to develop resistance to the antibiotic. The World Health Organization has flagged mupirocin resistance as a growing concern, partly driven by incomplete or unnecessary courses of the drug. Using it exactly as prescribed, for the full duration and no longer, is one of the simplest ways to protect its effectiveness.
What to Expect at the Application Site
Mild burning, stinging, or pain at the application site occurs in about 1.5% of people. Itching affects roughly 1%. These reactions are usually minor and tend to fade within minutes. If the burning or irritation gets worse with each application rather than better, or if you notice new redness spreading beyond the original infection, that’s worth mentioning to your prescriber since it could signal an allergic reaction or worsening infection.
A Note on Open Wounds and Kidney Issues
The ointment base contains polyethylene glycol, a common inactive ingredient that is normally harmless. On large open wounds or extensively damaged skin, however, polyethylene glycol can be absorbed into the bloodstream in significant amounts and is filtered out through the kidneys. If you have moderate or severe kidney problems, this formulation is not appropriate for use on large, open areas of skin. Your prescriber may choose the cream formulation instead, which uses a different base.
Storage
Keep the tube at room temperature, away from heat and direct light. Don’t freeze it. Make sure the cap is tightly closed after each use to prevent the ointment from drying out or becoming contaminated. Store it out of reach of children, and discard any leftover ointment once your treatment course is complete.