CrystagenvsLL-37

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)

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

Common

• Injection site reaction
• Mild fatigue
• Mild headache
• Minor digestive changes

Uncommon

• Flu-like symptoms

Serious

• No documented serious adverse effects

Common

• Local site irritation
• Transient stinging or burning
• Mild perilesional erythema
• Increased wound exudate

Uncommon

• Allergic contact reaction

Serious

• Hemolytic activity at systemic concentrations

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

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