Peptide library / Immune & defense / Bacitracin
Bacitracin
A cyclic peptide antibiotic found in many over-the-counter wound ointments.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Topical prevention of minor skin infectionsFDA approved
How it is thought to work
Bacitracin interferes with bacterial cell wall synthesis by blocking recycling of a lipid carrier.
What the evidence shows
Evidence for routine use on clean minor wounds is weak, and allergic reactions are not rare.
Safety and unknowns
Allergic contact dermatitis can occur. The injectable form was withdrawn after kidney toxicity concerns.
Regulatory status
FDA-approved in 1948. In 2020 the FDA requested withdrawal of the injectable form.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
More in Immune & defense
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In clinical trialsAn experimental antibiotic mimic of host defence peptides.
Colistin
FDA-approvedA last-resort polypeptide antibiotic for highly resistant Gram-negative infections.
Zilucoplan
FDA-approvedA macrocyclic peptide that blocks complement C5, approved for generalized myasthenia gravis.
General information, not medical advice. Do not buy or inject unregulated peptides.