Side-by-Side Comparison · 2026

Colistin vs Gramicidin S

Colistin vs Gramicidin S — mechanism, half-life, dosing, and research status compared. Which is right for your protocol?

Colistin
Antimicrobial Peptide

Colistin (polymyxin E) is a cyclic lipopeptide antibiotic structurally related to polymyxin B, differing in the fatty acid chain and one amino acid residue. Like polymyxin B, colistin targets LPS and disrupts outer membranes of Gram-negative bacteria....

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Gramicidin S
Antimicrobial Peptide

Gramicidin S (Soviet gramicidin) is a cyclic decapeptide antibiotic discovered in 1942 by Soviet scientists Gause and Brazhnikova from Bacillus brevis, during World War II. It became a frontline topical wound antiseptic for Soviet forces....

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Key Parameters
Parameter Colistin Gramicidin S
Category Antimicrobial Peptide Antimicrobial Peptide
Research FDA Approved Approved (topical, certain countries)
Half-Life Colistimethate (prodrug): 2-3 hours; active colistin: 14 hours Hours (topical)
Typical Dose 2.5-5 mg/kg/day CBA IV 0.1-0.5% in topical preparations
Frequency Every 8-12 hours As needed
Route IV (colistimethate) / Inhaled / Topical Topical
FDA Status Approved (systemic Gram-negative infections) Not FDA approved (approved in USSR/Russia, used in Europe)

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Frequently Asked Questions
What is the difference between Colistin and Gramicidin S?
Colistin: Colistin (polymyxin E) is a cyclic lipopeptide antibiotic structurally related to polymyxin B, differing in the fatty acid chain and one amino acid residue. Like polymyxin B, colistin targets LPS and ... Gramicidin S: Gramicidin S (Soviet gramicidin) is a cyclic decapeptide antibiotic discovered in 1942 by Soviet scientists Gause and Brazhnikova from Bacillus brevis, during World War II. It became a frontline topic...
Which has a longer half-life, Colistin or Gramicidin S?
Colistin half-life: Colistimethate (prodrug): 2-3 hours; active colistin: 14 hours. Gramicidin S half-life: Hours (topical).
Can you stack Colistin and Gramicidin S?
Colistin and Gramicidin S are in the same category and used together in research protocols. Always consult relevant literature and follow appropriate guidelines.

For research use only. Not medical advice. ASCEND does not conduct or endorse any specific research protocol. Always consult relevant scientific literature and regulatory guidelines.