One of the inactive ingredients in mupirocin ointment is polyethylene glycol (PEG). PEG can absorb into the body if it’s applied to open wounds or damaged skin. While very rare with a topical medication, too much PEG absorption could damage the kidneys. This can be dangerous if you already have kidney problems. Don't put mupirocin ointment in your eyes, nose, mouth, or vagina, either.
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