GHK Basic

Also known as: Copper-free GHK, GHK tripeptide, Apo-GHK

Evidence: Preclinical

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Overview

Copper-free form of the human tripeptide GHK (Gly-His-Lys), studied for collagen synthesis and wound repair, though nearly all published data use the copper complex.

GHK is a tripeptide first isolated from human plasma as a growth-modulating factor and synthesized in 1973 (Pickart 1973; Schlesinger 1977). The sequence occurs in the alpha-2 chain of type I collagen, which is where the wound-healing hypothesis comes from (Maquart 1988). GHK Basic is the apo form, sold without the copper ion. Nearly every published result uses the copper complex: GHK-Cu stimulated fibroblast collagen synthesis from 10 to the minus 12 M (Maquart 1988), and the proposed physiological role of the free peptide is to carry copper into cells (Pickart 1980). One 2024 commentary reports GHK alone reversing senescence markers and inducing apoptosis in myofibroblasts. The catalog also lists GHK-Cu (id 44), the copper complex, which is the molecule most of these references describe.

Benefits

Collagen synthesis in fibroblast culture, from 10 to the minus 12 M, peaking at 10 to the minus 9 M (in vitro, copper complex), wound repair in rodent and in vitro models, reversal of myofibroblast senescence markers (mouse and human cells). Copper-free GHK has no study of its own in any species

Dosing reference

Research dose: 1 to 5 mg daily: vendor and community range, no published human dose for GHK by any route
Range: 1000 to 5000 mcg, 1x daily
Reconstitution: 2 mL bacteriostatic water
Common vial sizes: 50 mg

Copper-free apo form, sold for subcutaneous or topical research use. Published work is in cell culture at molar concentrations (collagen stimulation from 10 to the minus 12 to 10 to the minus 9 M) or in topical formulations, not at a systemic dose. No study has dosed GHK in a human by injection. Copper availability matters for activity, so results obtained with the complex do not transfer to the apo form without that caveat.

Mechanism

The proposed mechanism for the free peptide is copper transport: GHK binds copper(II) with high affinity and the 1980 Nature paper concluded that its growth-modulating activity works by facilitating copper uptake into cells (Pickart 1980), with the solution structure of the complex solved two years later (Freedman 1982). Downstream effects are reported for the complex, not the apo form: GHK-Cu raised collagen synthesis in human fibroblast cultures in a concentration range starting at 10 to the minus 12 M and independent of cell number (Maquart 1988), and the gene-expression work describing broad resets of matrix and antioxidant programs used GHK-Cu or GHK in serum-containing media where copper is available (Pickart 2015). Copper-independent activity of the apo peptide has not been demonstrated.

Evidence

Preclinical: animal or in vitro data only

GHK was isolated from human plasma as a growth-modulating factor, identified as glycyl-histidyl-lysine and reproduced synthetically (Pickart et al., 1973; Schlesinger et al., 1977)
The free tripeptide's activity was attributed to facilitating copper uptake into cells, with the structure of the copper complex solved in 1982 (Pickart et al., 1980; Freedman et al., 1982)
GHK-Cu stimulated collagen synthesis in human fibroblast cultures from 10 to the minus 12 M, maximal at 10 to the minus 9 M, with no change in cell number (Maquart et al., 1988)
GHK reversed senescence markers and induced apoptosis in myofibroblasts and improved fibroblast migration and collagen contraction in aged mouse and human cells, reported in a 2024 commentary rather than a primary trial (He et al., 2024)
Peptide-copper complexes stimulated hair follicles in C3H mice; the hair-growth literature is on complexes, not the apo peptide (Trachy et al., 1991)
Human-trial status: no clinical trial of copper-free GHK exists in any indication. The human evidence for this sequence is cosmetic and formulation work on GHK-Cu, and FDA lists GHK-Cu for injectable routes in the withdrawn-nomination table of its compounding safety-risk page as of 2026-04-22

References

Side effects

No systemic safety data exist for GHK by any route, and no human trial has recorded adverse events for the copper-free form. Topical cosmetic use of this sequence is reported as well tolerated in formulation studies, with irritation, redness and stinging the commonly reported complaints (anecdotal). For the copper complex by injection, FDA states it may pose a risk of immunogenicity for certain routes and that no human safety data were identified; GHK-Cu sits in the withdrawn-nomination table of that page as of 2026-04-22.

Storage

Storage: Refrigerate 2-8°C (36-46°F)
Lyophilized: 2+ years at room temp, 3+ years refrigerated
Reconstituted: 28-30 days refrigerated

Pharmacology

Half-life: No pharmacokinetic study of GHK or GHK-Cu has been published in any species. GHK is present in human plasma and its concentration is reported to decline with age (Pickart 2015)
Bioavailability: Not measured by any route in any species. Topical delivery of this sequence is studied as a formulation problem, and the apo peptide's activity depends on binding copper once in contact with tissue
Molecular weight: 340.38 Da
Sequence: GHK (apo form, no copper ion)