Mupirocin Side Effects: What to Expect and When to Call Your Doctor

Mupirocin is generally one of the best-tolerated prescription antibiotics available. Because it's applied topically rather than taken orally or by injection, it has very little systemic absorption — meaning most side effects stay local to the application site rather than affecting the whole body.

That said, any medication can cause reactions, and it's important to know what to expect, what's normal, and what warrants a call to your doctor.

Common Side Effects of Mupirocin (Topical Use)

These side effects occur in a small percentage of patients (roughly 0.3% or more in clinical studies) and are generally mild:

Burning, stinging, or pain at the application site — especially if applied to an open wound or inflamed skin. This usually subsides quickly.

Itching (pruritus) at or near the treated area.

Rash or contact dermatitis — a mild skin reaction to mupirocin itself or its vehicle (the inactive ingredients, such as polyethylene glycol in the ointment).

Headache — more commonly reported with intranasal use (from former Bactroban nasal formulation), but occasionally reported with topical use.

Nausea — rare with topical application; more associated with intranasal use.

These effects are typically mild and do not require stopping the medication. If burning or stinging at the site is bothersome, applying a thin layer and allowing it to air-dry for a few minutes may help.

Serious Side Effects — Stop Using Mupirocin and Call Your Doctor

Serious side effects from topical mupirocin are rare, but they do occur. Stop using mupirocin and seek medical attention immediately if you experience:

Signs of a severe allergic reaction: Hives, rapid or pounding heartbeat, wheezing, difficulty breathing, or swelling of the face, lips, tongue, or throat. This may indicate anaphylaxis, which is rare but serious.

Worsening skin reaction: Severe inflammation, blistering, peeling, or worsening rash at the application site that may indicate exfoliative dermatitis or sensitization.

Severe diarrhea: Watery or bloody diarrhea — even months after stopping mupirocin — can indicate Clostridioides difficile (C. diff) colitis, though this is rare with a topical antibiotic.

Signs of fungal overgrowth: If using mupirocin for more than 10 days, you may notice a new or different type of skin infection. Prolonged antibiotic use can allow fungi or non-susceptible bacteria to flourish.

When Is Mupirocin Not Safe to Use?

There is only one absolute contraindication to mupirocin: known hypersensitivity (allergy) to mupirocin itself or any ingredient in the formulation (such as polyethylene glycol in the ointment). Important safety notes:

Do NOT get mupirocin in your eyes — rinse immediately with water if this happens.

Do NOT use the skin ointment inside the nose — this formulation is not designed for mucosal use. (Note: the nasal formulation, Bactroban nasal, has been discontinued.)

Do NOT apply other creams, ointments, or lotions to the same area at the same time.

Use with caution in patients with moderate-to-severe kidney problems — the PEG vehicle can accumulate.

Avoid use on extensive burn wounds (large PEG absorption risk).

Is Mupirocin Safe During Pregnancy and Breastfeeding?

Mupirocin is generally considered safe for topical use during pregnancy. Decades of data have not identified a drug-associated risk of major birth defects or miscarriage. Systemic absorption through intact skin is minimal — less than 1.25% of the applied dose is absorbed. Animal studies at doses far higher than typical topical use showed no fetal harm.

For breastfeeding: it is unknown whether mupirocin passes into breast milk, but given minimal systemic absorption, the risk is considered very low. If applied to the breast or nipple area, wash thoroughly before nursing. Always tell your healthcare provider if you are pregnant or breastfeeding before starting any medication.

No Known Drug Interactions

One of mupirocin's advantages is that it has essentially no known drug interactions. Its minimal systemic absorption means it doesn't interfere with other oral or IV medications you may be taking. There are also no known interactions with food, alcohol, or supplements when used topically. However, always inform your healthcare provider of all medications you take, including OTC products and supplements.

For a detailed look at mupirocin interactions, see our article on mupirocin drug interactions. If your pharmacy is out of mupirocin, medfinder can help you find it in stock nearby.