Peptide Comparison
Magainin-2vsLL-37
Amphipathic 23-amino-acid antimicrobial peptide from Xenopus laevis skin — the founding member of the magainin family discovered by Michael Zasloff at NIH in 1987, operating through the toroidal pore membrane disruption model with broad-spectrum activity against Gram-positive and Gram-negative bacteria, whose synthetic derivative Pexiganan (MSI-78) advanced to Phase III clinical trials for diabetic foot ulcers
Human cathelicidin-derived antimicrobial peptide (37 amino acids) that disrupts bacterial membranes at MIC 0.62 μM against S. aureus, neutralizes endotoxin (LPS) to prevent septic shock, and has reached Phase II clinical trials as Ropocamptide for wound healing — achieving 6-fold accelerated healing at 0.5 mg/mL in venous leg ulcers
At a Glance
Quick
comparison
Dose Range
Magainin-2
1–5 mg
LL-37
0.5–1.6 mg/mL (topical)
Frequency
Magainin-2
Multiple times daily
LL-37
Once daily
Administration
Magainin-2
Topical application (primary clinical route)
LL-37
Topical application (wound healing)
Cycle Length
Magainin-2
4-6 weeks
LL-37
12+ weeks
Onset Speed
Magainin-2
Rapid (hours to days)
LL-37
Moderate (1-2 weeks)
Evidence Level
Magainin-2
Moderate human trials (Phase 1-2)
LL-37
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Fighting Infections
Resistance Prevention
Wound Healing
Immune Boost
Technical Data
Compound
specifications
Magainin-2
Molecular Formula
C114H180N30O29S
Molecular Weight
2,466.9 g/mol (magainin-2); Pexiganan (MSI-78): ~2,500 Da
Half-Life
Plasma half-life: minutes (rapid proteolytic degradation by serum proteases); local tissue persistence in wound environment: hours at therapeutic concentrations
Bioavailability
Topical bioavailability: local tissue concentrations achieve bactericidal levels with 1-2% cream formulation; systemic bioavailability minimal — rapidly degraded by tissue proteases if absorbed; poor oral bioavailability
CAS Number
108433-95-0
LL-37
Molecular Formula
C205H340N60O53
Molecular Weight
4,493.26 Da
Half-Life
Short systemic half-life (minutes) due to protease susceptibility; local tissue persistence at wound sites is longer due to binding to extracellular matrix components and lipid membranes
Bioavailability
Topical application achieves high local wound-bed concentrations; systemic bioavailability limited by rapid proteolytic degradation and serum protein binding; not intended for oral delivery
CAS Number
154947-66-7
Protocols
Dosing
tiers
Magainin-2
LL-37
Applications
Best
suited for
Magainin-2
Research into topical antimicrobial peptides for diabetic foot ulcer management
Magainin-2 is particularly well-suited for individuals focused on research into topical antimicrobial peptides for diabetic foot ulcer management. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Understanding the toroidal pore model of antimicrobial peptide membrane disruption
Magainin-2 is particularly well-suited for individuals focused on understanding the toroidal pore model of antimicrobial peptide membrane disruption. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Development of resistance-proof antimicrobial agents targeting membrane architecture
Magainin-2 is particularly well-suited for individuals focused on development of resistance-proof antimicrobial agents targeting membrane architecture. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Investigation of selective anticancer activity mediated by membrane phospholipid asymmetry
Magainin-2 is particularly well-suited for individuals focused on investigation of selective anticancer activity mediated by membrane phospholipid asymmetry. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
LL-37
Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
LL-37 is particularly well-suited for individuals focused on treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
LL-37 is particularly well-suited for individuals focused on immune defense against antibiotic-resistant bacterial infections (mrsa, pseudomonas). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Anti-biofilm strategies for chronic wound infections and medical device-associated infections
LL-37 is particularly well-suited for individuals focused on anti-biofilm strategies for chronic wound infections and medical device-associated infections. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Boosting innate immune defense in immunocompromised or aging individuals
LL-37 is particularly well-suited for individuals focused on boosting innate immune defense in immunocompromised or aging individuals. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Safety Profile
Side
effects
Magainin-2
Common
- Application site burning/stinging
- Local erythema
- Mild pruritus
- Increased wound exudate
Uncommon
- Contact sensitization
Serious
- No serious systemic adverse effects documented
LL-37
Common
- Local site irritation
- Transient stinging or burning
- Mild perilesional erythema
- Increased wound exudate
Uncommon
- Allergic contact reaction
Serious
- Hemolytic activity at systemic concentrations
Research Status
Safety
& evidence
Magainin-2
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Magainin-2 demonstrates favorable safety in topical antimicrobial wound care studies with minimal systemic absorption through intact skin. Local tissue irritation minimal at therapeutic concentrations (0.1-1% w/w); hemolytic activity negligible at concentrations <10 μM. No serious adverse events in Phase II wound healing trials. Peptide stability dependent on formulation pH; activity preserved at physiologic pH. Resistance development slower than traditional antibiotics.
Contraindications
- xKnown hypersensitivity to magainin peptides or amphibian-derived proteins
- xPregnancy and breastfeeding — insufficient safety data for magainin-derived therapeutics
- xDeep tissue infections requiring systemic antimicrobial therapy — topical magainin has limited tissue penetration depth
- xSevere peripheral vascular disease with non-viable tissue — antimicrobial peptides require viable tissue interface for effective action
LL-37
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
LL-37 is an endogenous cathelicidin antimicrobial peptide naturally produced by immune cells and epithelial tissues, conferring inherent biocompatibility and low toxicity at physiological concentrations. Synthetic LL-37 shows excellent safety in in vitro immune assays and animal models with no hepatotoxicity, nephrotoxicity, or genotoxicity at relevant doses. At elevated concentrations, the cationic amphipathic structure can cause hemolysis and cell membrane damage, but therapeutic doses are far below these thresholds. Injection site reactions are minimal in research applications.
Contraindications
- xKnown hypersensitivity to cathelicidin peptides or formulation components
- xActive hemolytic conditions — LL-37 demonstrates concentration-dependent hemolytic activity
- xPregnancy and breastfeeding — insufficient reproductive safety data from clinical trials
- xSevere renal impairment — peptide clearance may be altered
Decision Guide
Which is
right for you?
Choose Magainin-2 if...
- Research into topical antimicrobial peptides for diabetic foot ulcer management
- Understanding the toroidal pore model of antimicrobial peptide membrane disruption
- Development of resistance-proof antimicrobial agents targeting membrane architecture
- Investigation of selective anticancer activity mediated by membrane phospholipid asymmetry
Choose LL-37 if...
- Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
- Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
- Anti-biofilm strategies for chronic wound infections and medical device-associated infections
- Boosting innate immune defense in immunocompromised or aging individuals