Peptide Comparison
CrystagenvsLL-37
Immunogeroprotective tripeptide bioregulator (Glu-Asp-Pro) that optimally stimulates thymic epithelial cell proliferation at 200 ng/mL, suppresses thymocyte apoptosis through p53 downregulation and Ki-67 upregulation, and contributed to a 4.1-fold mortality reduction in a 266-person 6-8 year clinical study when combined with complementary pineal peptides
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
Crystagen
1–100 mcg/kg
LL-37
0.5–1.6 mg/mL (topical)
Frequency
Crystagen
Once daily
LL-37
Once daily
Administration
Crystagen
Subcutaneous injection
LL-37
Topical application (wound healing)
Cycle Length
Crystagen
8-12 weeks
LL-37
12+ weeks
Onset Speed
Crystagen
Gradual (3-4 weeks)
LL-37
Moderate (1-2 weeks)
Evidence Level
Crystagen
Limited human trials
LL-37
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Immune Rejuvenation
Healthy Aging
Cancer Defense
Wound Healing
Fighting Infections
Immune Boost
Technical Data
Compound
specifications
Crystagen
Molecular Formula
C14H21N3O8
Molecular Weight
359.3 g/mol
Half-Life
Short plasma half-life typical of tripeptides (minutes); biological effects persist for weeks to months through gene expression modifications and thymic microenvironment restoration; metabolized to constituent amino acids
Bioavailability
Absorbed via intestinal peptide transporters (PepT1/POT and LAT carrier families) when administered orally; rapid absorption from subcutaneous injection sites; efficient cellular uptake due to ultra-short tripeptide structure
CAS Number
Not assigned (patented as immunogeroprotective peptide, US8057810B2)
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
Crystagen
LL-37
Applications
Best
suited for
Crystagen
Restoring thymic function and immune competence in aging individuals with immune senescence
Crystagen is particularly well-suited for individuals focused on restoring thymic function and immune competence in aging individuals with immune senescence. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Comprehensive Khavinson bioregulator protocols for immune and anti-aging support
Crystagen is particularly well-suited for individuals focused on comprehensive khavinson bioregulator protocols for immune and anti-aging support. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Supporting immune function during and after illness recovery
Crystagen is particularly well-suited for individuals focused on supporting immune function during and after illness recovery. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Geroprotective immunomodulation to extend healthspan and reduce age-related disease incidence
Crystagen is particularly well-suited for individuals focused on geroprotective immunomodulation to extend healthspan and reduce age-related disease incidence. 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
Crystagen
Common
- Injection site reaction
- Mild fatigue
- Mild headache
- Minor digestive changes
Uncommon
- Flu-like symptoms
Serious
- No documented serious adverse 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
Research Status
Safety
& evidence
Crystagen
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
Crystagen is a crystalline protein extract (likely containing collagen-derived peptides) from animal tissues that is not FDA-approved and has essentially no published safety data in medical literature. As an undefined and poorly characterized biological mixture, batch consistency, sterility, and identity cannot be verified. Potential risks include allergic reactions to animal proteins, contamination from source tissues, and unknown immunological effects. No formal safety assessments, animal studies, toxicology screening, or human clinical trials exist. The product appears to exist primarily in Russian medical markets, and little information about its actual composition or manufacturing is publicly available.
Contraindications
- xKnown hypersensitivity to peptide bioregulators or constituent amino acids (glutamic acid, aspartic acid, proline)
- xPregnancy and breastfeeding — insufficient reproductive safety data
- xActive autoimmune disease in flare without physician supervision
- xOrgan transplant recipients on immunosuppression — potential interference with immunosuppressive regimens
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 Crystagen if...
- Restoring thymic function and immune competence in aging individuals with immune senescence
- Comprehensive Khavinson bioregulator protocols for immune and anti-aging support
- Supporting immune function during and after illness recovery
- Geroprotective immunomodulation to extend healthspan and reduce age-related disease incidence
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