Mupirocin: What It Is, How It Works, and When It's Used

When you have a small but stubborn skin infection—like a scraped knee that won’t heal or a red, oozing spot near your nose—you might be prescribed mupirocin, a topical antibiotic that targets bacteria directly on the skin. Also known as Bactroban, it’s one of the few antibiotics designed to be applied right where the problem is, without sending chemicals through your whole body. Unlike oral antibiotics that circulate everywhere, mupirocin works locally, making it perfect for surface-level bugs like Staphylococcus aureus, a common bacterium that causes impetigo, folliculitis, and infected cuts.

Mupirocin isn’t just for open wounds. Doctors often use it to clear MRSA, a dangerous strain of staph resistant to many common antibiotics from the nose before surgery or to stop it from spreading in hospitals. That’s why some people get a little tube of mupirocin ointment to rub inside their nostrils—yes, really. It’s not a cure-all, but it’s one of the most effective tools we have for stopping bacterial spread before it becomes a bigger problem. It doesn’t work on viruses or fungi, and it’s not meant for deep infections like abscesses. If your skin issue is swollen, hot, or spreading fast, you’ll likely need something stronger.

You’ll find mupirocin in two forms: a cream for wounds and a nasal ointment for carriers. The cream is usually applied three times a day for up to 10 days. The nasal version is used for 5 days, often alongside other treatments. It’s not something you take long-term—overuse can lead to resistant strains, and it’s not designed to replace good hygiene. If you’ve ever had a rash that didn’t improve with over-the-counter creams, mupirocin might’ve been the next step. Many of the posts below dive into how it compares with other topical treatments, what to watch for if it doesn’t work, and how it fits into broader infection control strategies. Whether you’re using it for a child’s impetigo, a post-surgery precaution, or a recurring skin flare-up, understanding how mupirocin actually works helps you use it right—and know when to ask for more help.