Skin & aging Polypeptide antibiotic
Bacitracin
Regulatory status
Status at a glance
503A compounding status
Not nominated
We found no pending nomination for the 503A bulks list. Unless the substance has another legal pathway (for example, a USP monograph or use in an FDA-approved drug), 503A pharmacies generally may not compound with it.
- FDA approval
- An FDA-approved product contains this peptide
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
If you think you are having a medical emergency, call 911.
Key takeaway
Bacitracin is a cyclic polypeptide antibiotic produced by Bacillus bacteria that kills gram-positive bacteria by blocking the construction of their cell wall. It is best known as an over-the-counter topical ointment for preventing infection in minor cuts, scrapes, and burns, often combined with neomycin and polymyxin B in "triple antibiotic" products. It is widely available over the counter, but it is also a common cause of allergic skin reactions, and its injectable form was withdrawn over kidney-toxicity concerns.
At a glance
- FDA status
- FDA-approved polypeptide antibiotic, sold over the counter as a topical ointment for minor wounds
- How it works
- Produced by Bacillus bacteria; blocks bacterial cell-wall synthesis, mainly against gram-positive bacteria
- Combinations
- Frequently combined with neomycin and polymyxin B in "triple antibiotic" ointments
- Safety
- Frequent cause of allergic contact dermatitis; named "Allergen of the Year" in 2003
- Evidence strength
- FDA approved
Summary
Bacitracin is an FDA-approved peptide antibiotic used on the skin for minor wounds. Learn how it works, how it is used, and why it can cause allergies.
What is bacitracin?
Bacitracin is an antibiotic that is actually a mixture of closely related cyclic polypeptides, produced by bacteria in the Bacillus subtilis group. It is a peptide antibiotic rather than a small-molecule drug, and its main component, bacitracin A, is the most active.
It is used almost entirely on the skin. In the United States, it is widely available over the counter as an ointment for minor wound care, both on its own and combined with other topical antibiotics.
The history of bacitracin
Bacitracin owes its name to a child. In 1945, researchers isolated the antibiotic-producing Bacillus strain from the wound of a seven-year-old girl named Margaret Tracy, and the drug's name combines "Bacillus" with "Tracy."
It arrived during the early antibiotic era, shortly after penicillin. Its toxicity when injected limited its use as a systemic drug, but it found a durable place as a topical antibiotic that is still sold today.
How does bacitracin work?
Bacitracin kills bacteria by blocking the construction of their cell wall. It interferes with a recycling step in wall-building: A lipid carrier molecule (C55 or undecaprenyl pyrophosphate) ferries the building blocks of the wall across the bacterial membrane, and it must shed a phosphate to be reused. Bacitracin binds that carrier and prevents its dephosphorylation, so the carrier is pulled out of circulation and new cell-wall material can no longer be delivered.
Because this target matters most in gram-positive bacteria, bacitracin's activity is strongest against organisms such as staphylococci and streptococci. It is poorly absorbed through the skin, which is part of why it works well as a surface antibiotic but is not used orally for body-wide infection.
Is it FDA-approved?
Editor’s note
Status: FDA-approved polypeptide antibiotic, sold over the counter as a topical ointment for minor wounds
Category: FDA-approved · Primary body area: Skin & aging
Yes, and much of it is sold without a prescription. Its status depends on the form, and the injectable form is the exception:
| Form | Status | Detail |
|---|---|---|
| Topical | Over-the-counter drug | Prevents infection in minor cuts, scrapes, and burns |
| Ophthalmic (eye) ointment | Prescription | Available in prescription eye ointments |
| Injection | Approval withdrawn in 2020 | The FDA withdrew approval because of the risk of serious kidney damage, so the systemic version is no longer marketed in the United States |
What is bacitracin used for?
Bacitracin is used to prevent infection in minor skin wounds such as cuts, scrapes, and burns, and it is a common ingredient in first-aid ointments. It is frequently combined with neomycin and polymyxin B in "triple antibiotic" products to broaden the range of bacteria covered.
One nuance is worth knowing: for clean minor wounds, antibiotic ointment is not clearly better than plain petroleum jelly. In a randomized trial of 922 dermatologic-surgery patients, white petrolatum and bacitracin produced comparable, low infection rates, while only the bacitracin group had cases of allergic contact dermatitis. That has led many clinicians to favor plain petrolatum for routine wound care.
What are the side effects?
The most notable side effect of bacitracin is allergy. Its main risks are:
- Allergic contact dermatitis: it is a well-recognized cause of this itchy, red, sometimes blistering rash where it is applied, and in 2003, the American Contact Dermatitis Society named it "Allergen of the Year."
- Anaphylaxis: more rarely, topical bacitracin has triggered anaphylaxis, a severe whole-body allergic reaction, which is unusual for an over-the-counter ointment.
- Kidney damage: when given by injection, bacitracin can cause serious kidney damage, which is why that form was taken off the U.S. market.
Applied topically to small areas, it is generally well tolerated apart from the allergy risk.
Sources: mechanism and pharmacology from DrugBank and StatPearls; the comparison with white petrolatum from the randomized controlled trial by Smack et al. in JAMA (1996), indexed on PubMed (PMID 8805732); and clinical reporting on bacitracin allergy, including its 2003 "Allergen of the Year" designation. This document is educational and does not constitute medical advice.
Registered human trials
0 registered human trials on ClinicalTrials.gov that we reviewed
Sources
- [1]
- [2]
- [3]
- [4]
- PMID 8805732
- [5]
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