LL-37 vs Thymopoietin
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
Thymic hormone that supports T-cell development and immune function, with the active fragment thymopentin (TP-5) used in clinical research
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
LL-37
1.6–1.6 mg/mL
Thymopoietin
50–50 mg
Frequency
LL-37
Once daily
Thymopoietin
Every other day
Administration
LL-37
Topical application (wound healing)
Thymopoietin
Subcutaneous injection
Cycle length
LL-37
12+ weeks
Thymopoietin
4-6 weeks
Onset speed
LL-37
Moderate (1-2 weeks)
Thymopoietin
Moderate (1-2 weeks)
Evidence level
LL-37
Moderate human trials (Phase 1-2)
Thymopoietin
Limited human trials
Benefit ratings
Wound Healing
Fighting Infections
Immune Boost
Immune Cell Development
Post-Surgical Recovery
Cancer Immunotherapy Enhancement
Compound specifications
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
Thymopoietin
Molecular formula
C246H404N66O73
Molecular weight
5454
Half-life
Minutes to hours in plasma
Bioavailability
Moderate with subcutaneous injection
CAS number
67632-30-6
Dosing compared
LL-37
Topical
0.5 mg/mL gel
Twice weekly · 4 weeks
Lowest dose in the LL-37 (ropocamptide) Phase I/IIa venous leg-ulcer trial and the most effective: ~6-fold faster healing and ~68% ulcer-area reduction vs placebo, applied to the wound twice weekly [4].
1.6 mg/mL gel
Twice weekly · 4 weeks
Mid dose in the same trial; ~3-fold improvement and ~50% area reduction vs placebo. The highest tested concentration (3.2 mg/mL) showed no benefit over placebo, so dose escalation above this is not supported [4].
Thymopoietin
Subcutaneous injection
50 mg (as the active thymopentin/TP-5 pentapeptide)
Three times weekly · 6 weeks to several months
The full-length thymopoietin hormone is not dosed directly in humans; its immune activity is delivered clinically through its active pentapeptide fragment thymopentin (TP-5), studied at 50 mg SC three times weekly [5].
Best suited for
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.
Thymopoietin
Cancer Treatment Support
Used alongside chemotherapy to maintain immune function and reduce treatment side effects while enhancing anti-tumor immunity
Post-Surgical Immune Recovery
Helps restore T-cell function and prevent immune depression following major surgery or serious medical stress
HIV-Related Immune Support
Combined with antiretroviral therapy to support T-cell populations and improve immune response
Side effects
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
Thymopoietin
Common
- Injection site redness or swelling
- Mild fever
- Transient lymphocytosis
Uncommon
- Mild to moderate fatigue
- Temporary headaches
- Joint or muscle aches
Serious
- Neuromuscular weakness or myasthenia-like symptoms
- Severe allergic reaction (anaphylaxis)
- Autoimmune flare
Safety & evidence
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
- Known hypersensitivity to cathelicidin peptides or formulation components
- Active hemolytic conditions — LL-37 demonstrates concentration-dependent hemolytic activity
- Pregnancy and breastfeeding — insufficient reproductive safety data from clinical trials
- Severe renal impairment — peptide clearance may be altered
Thymopoietin
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
Thymopoietin is a naturally-derived thymic hormone with a well-characterized mechanism but limited human safety data. Most clinical experience comes from thymopentin (TP-5), the active pentapeptide fragment. It is generally well-tolerated but has important safety considerations, particularly regarding neuromuscular effects.
Contraindications
- Myasthenia gravis or other neuromuscular junction disorders
- Active autoimmune diseases
- Pregnancy and breastfeeding
- Severe allergic reactions to thymic proteins
Which is right for you?
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
Choose Thymopoietin if...
- Supporting immune function during cancer treatment
- Recovering immune function after surgery
- Managing HIV-related immune deficiencies
- Enhancing response to other immunotherapies