Peptide library / Immune & defense / Colistin
Colistin
A last-resort polypeptide antibiotic for highly resistant Gram-negative infections.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Multidrug-resistant Gram-negative infectionsFDA approved
How it is thought to work
Colistin disrupts the outer membrane of Gram-negative bacteria by binding the lipid A of lipopolysaccharide.
What the evidence shows
Revived for use in the 2000s due to carbapenem-resistant bacteria, with evidence mainly from observational studies.
Safety and unknowns
Kidney and nerve toxicity are common and dose limiting.
Regulatory status
FDA-approved in 1959.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.