Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of GHK and LL-37 — mechanism, dosing, side effects, legal status, and pricing.
GHK is the parent tripeptide Gly-His-Lys, originally isolated from human plasma by Loren Pickart (1973) as an activity that caused aged hepatocytes to synthesize proteins like younger tissue. It is DISTINCT from GHK-Cu, the 1:1 copper(II) complex tracked as a separate entry — but GHK binds copper readily in vivo, so in physiological environments the bare peptide rapidly associates with available Cu(II). Not FDA-approved for any indication; used in cosmetic and research contexts only.
LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide (starting with two leucines) cleaved from the hCAP-18 precursor. It has broad-spectrum antimicrobial activity and immunomodulatory roles, but is also implicated in the pathogenesis of autoimmune and inflammatory skin diseases including psoriasis, rosacea, and lupus. Not FDA-approved; research-use only.
GHK
LL-37
Category
Legal Status
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Route
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
GHK
LL-37
COA corpus from Disclosed Labs — independently tested batches only.
GHK
No COA data yet.
Submit testing data →LL-37
31
COAs
99.2%
Avg purity
8
Labs
GHK is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. LL-37 remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
The overwhelming majority of GHK research uses the GHK-Cu complex; direct studies of copper-free GHK are limited. Pickart (J Biomater Sci Polym Ed, 2008, PMID 18644225) reviewed GHK's role in tissue remodeling and wound healing. Pickart et al. (Oxid Med Cell Longev, 2012, PMID 22666519) reviewed GHK-Cu in oxidative stress and cognitive aging. Pickart, Vasquez-Soltero & Margolina (BioMed Res Int, 2014, PMID 25302294; 'GHK and DNA: Resetting the Human Genome to Health') summarized microarray data indicating GHK modulates expression of thousands of human genes. No human clinical trials exist for injected bare GHK; cosmetic formulations typically use topical GHK or GHK-Cu at ~50–200 ppm.
Key references
LL-37 was characterized in the mid-1990s as the processed antimicrobial product of hCAP-18 (Gudmundsson et al., 1996). Dürr et al. (2006, Biochim Biophys Acta, PMID 16716248) provided a foundational review of its structure and activity as the sole human cathelicidin. Overhage et al. (2008, Infection and Immunity, PMID 18591225) showed LL-37 prevents Pseudomonas aeruginosa biofilm formation at 0.5 µg/mL — far below its MIC. A randomized, placebo-controlled Phase 1/2 trial (Grönberg et al., 2014, Wound Repair and Regeneration, PMID 25041740) found topical LL-37 safely accelerated healing of hard-to-heal venous leg ulcers at low doses. Its dual role in autoimmunity is well established: Lande et al. (2014, Nature Communications, PMID 25470744) identified LL-37 as a T-cell autoantigen in two-thirds of moderate-to-severe plaque psoriasis patients. No FDA approval exists for any indication. Injectable grey-market protocols for Lyme, biofilm, or mold illness lack controlled clinical evidence and carry theoretical autoimmune risk given LL-37's role in psoriasis, lupus, and rosacea pathogenesis.
GHK (Cosmetic) and LL-37 (Immune) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Frequency
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Key references
Disclosed Labs