Peptide Comparison
PidotimodvsLL-37
Synthetic dipeptide immunomodulator that enhances both innate and adaptive immunity through Toll-like receptor activation
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
Pidotimod
400–800 mg
LL-37
0.5–1.6 mg/mL (topical)
Frequency
Pidotimod
Multiple times daily
LL-37
Once daily
Administration
Pidotimod
Oral (tablet)
LL-37
Topical application (wound healing)
Cycle Length
Pidotimod
12+ weeks
LL-37
12+ weeks
Onset Speed
Pidotimod
Moderate (1-2 weeks)
LL-37
Moderate (1-2 weeks)
Evidence Level
Pidotimod
Moderate human trials (Phase 1-2)
LL-37
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Immune
Healing & Recovery
Anti-Aging
Wound Healing
Fighting Infections
Immune Boost
Technical Data
Compound
specifications
Pidotimod
Molecular Formula
C9H12N2O4S
Molecular Weight
244.27 g/mol
Half-Life
Approximately 4 hours
Bioavailability
~45% (oral)
CAS Number
121808-62-6
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
Pidotimod
LL-37
Applications
Best
suited for
Pidotimod
Recurrent Respiratory Infections
Pidotimod is specifically indicated and most widely studied for preventing recurrent respiratory tract infections (RRTIs), particularly in children over 3 years. Multiple clinical studies and a Phase 4 trial with 338 children have demonstrated significant reductions in infection frequency and duration.
Immunocompromised Patients
Patients with documented cell-mediated immunodepression, including those with HIV or the elderly with weakened immune function, may benefit from pidotimod's ability to enhance T-cell function and rebalance cytokine production.
Seasonal Immune Support
Preventive courses before cold and flu season can strengthen immune defenses through TLR activation and enhanced mucosal immunity (increased salivary IgA), reducing susceptibility to viral respiratory infections.
Chronic Respiratory Conditions
Patients with chronic bronchitis, bronchiectasis, or COPD who experience frequent exacerbations may benefit from pidotimod as an adjunctive therapy to reduce infection-triggered flares.
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
Pidotimod
Common
- Gastrointestinal discomfort
- Skin rash
- Headache
- Nausea
- Diarrhea
- Transient fever
Uncommon
- Allergic reaction
Serious
- Severe hypersensitivity reaction
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
Pidotimod
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Pidotimod (immuno-stimulating dipeptide analog) has 40+ years of safety data in European/Asian markets with favorable tolerability profile. Mild gastrointestinal effects occur in <5% of users; no serious adverse events in 25 years of clinical use across 50,000+ patient population. Oral bioavailability excellent with rapid intestinal absorption. No mutagenicity or carcinogenicity in preclinical testing; immunomodulatory mechanism carries theoretical risk in severely immunocompromised patients.
Contraindications
- xKnown hypersensitivity to pidotimod or any excipients
- xPregnancy and breastfeeding (insufficient safety data)
- xChildren under 3 years of age
- xSevere autoimmune disease in active flare
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 Pidotimod if...
- Preventing recurrent respiratory tract infections
- Supporting immune function in immunocompromised individuals
- Reducing frequency of infections in children and elderly
- Immune support during HIV management
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