Educational reference only. Informational material drawn from peer-reviewed literature. Not medical advice and not a recommendation to use, dose, or modify any therapy. Decisions about hormone therapy should be made with a qualified healthcare provider.
Overview
Overview
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex, also called Copper Tripeptide-1 or PC-1) is a small peptide complex with substantial evidence for one use pattern (topical cosmetic application) and minimal evidence for another (systemic injection). The compound is a 3-amino acid peptide (GHK) bound to a copper ion (Cu²⁺), originally isolated from human plasma in 1973 and characterized as a peptide that declines with age and has tissue regenerative properties.
GHK-Cu has an unusually well-established place in cosmetic science: widely used in topical skincare for over 40 years, listed in cosmetic product ingredient regulations as Copper Tripeptide-1, multiple clinical trials in topical applications for skin aging, wound healing, and tissue regeneration, generally regarded as safe (GRAS) for topical cosmetic use.
For systemic injection use, which has emerged in non-medical contexts, the evidence base is substantially weaker. Most claims about injected GHK-Cu derive from extrapolation of topical and in vitro data, with limited direct human evidence for injectable applications. The two use patterns should be evaluated separately.
Forms
Available forms & half-lives
| Form | Approximate half-life |
|---|---|
| Topical cosmetic creams/serums (well-established) | Local action; minimal systemic absorption |
| Topical wound dressings (specialty) | Local action |
| Subcutaneous/intramuscular injection (research chemical) | ~6–12 hours (limited human data) |
What it does
Main effects
- TOPICAL: Reduced wrinkles and improved skin texture: multiple human trials of topical creams demonstrate measurable skin improvements over 12-week protocols
- TOPICAL: Increased collagen synthesis: Abdulghani et al. (1999) showed collagen increases in 70% of topical-cream volunteers, outperforming vitamin C and tretinoin comparators
- TOPICAL: Improved skin elasticity, hydration, and density: demonstrated across multiple trials including Krüger et al. pilot study in aged skin
- TOPICAL: Wound healing acceleration: clinical evidence in diabetic foot ulcers and Mohs surgical wounds
- TOPICAL: Hair growth stimulation in some applications
- TOPICAL: Reduction of age spots and improved skin contrast
- Gene expression modulation: affects >4,000 human genes including collagen synthesis, antioxidant defense, DNA repair, anti-inflammatory, and angiogenesis pathways PMC: 6073405
- INJECTABLE: Systemic tissue regeneration claims: based on animal injection studies showing systemic healing effects at distant body sites; no completed Phase 2 or Phase 3 controlled human trials
- INJECTABLE: Anti-aging and bone/liver/lung repair: claimed but supported primarily by animal injection studies and topical/in vitro extrapolation
- Endogenous human peptide: declines with age (~200 ng/mL at 20 → ~80 ng/mL at 60); this is the conceptual basis for supplementation hypotheses but does not by itself establish supplementation benefit
What to watch for
Common side effects
- Topical safety is excellent: 40+ years of cosmetic use; rare mild local irritation; occasional contact dermatitis in copper-sensitive individuals; no systemic toxicity from typical topical use
- Injectable safety is substantially less well-characterized: limited controlled clinical data; reasonable theoretical concerns
- Injection site reactions: pain, redness, swelling reported anecdotally
- Mild fatigue, headache, mild metallic taste (related to copper): reported in non-medical injection use
- Theoretical pathological angiogenesis concerns: same class concern as BPC-157/TB-500; could theoretically promote cancer angiogenesis, worsen diabetic retinopathy, or affect other angiogenesis-dependent pathologies
- Theoretical copper accumulation with long-term injectable use: relatively small amounts in typical use likely not problematic but long-term effects not characterized
- Contraindicated in Wilson's disease (impaired copper metabolism)
- Product identity and purity are unvalidated for injectable material: research-grade GHK-Cu varies in identity, copper concentration, purity and sterility, and its storage stability is complex
- CO2 laser resurfacing trial was negative: no statistically significant improvement in erythema resolution; one of the negative trials in the literature
Key facts
Key facts worth knowing
- GHK was first isolated from human plasma in 1973 by Loren Pickart, who observed that plasma from young donors stimulated liver cells from older donors to produce more proteins characteristic of younger donors. The active component was identified as the GHK tripeptide.
- Endogenous GHK levels decline with age, from approximately 200 ng/mL at age 20 to ~80 ng/mL at age 60. This age-related decline is the conceptual basis for supplementation hypotheses.
- The copper ion is essential to the activity. GHK has high affinity for Cu²⁺ and the GHK-Cu complex appears to be the biologically active form. The copper binding affects stability of the peptide, activity in biological systems, distribution to tissues, and specific cellular effects.
- Strong topical evidence base. Multiple clinical trials have demonstrated GHK-Cu effects on reducing wrinkles and improving skin texture, increasing collagen synthesis, improving skin elasticity and hydration, accelerating wound healing in specific contexts, and hair growth in some applications.
- The mechanism involves gene expression modulation. GHK-Cu affects expression of over 4,000 human genes (based on transcriptomic analysis), with effects on collagen synthesis pathways, antioxidant response, anti-inflammatory pathways, DNA repair pathways, and angiogenesis. PMC: 6073405
- Injection-based use has limited evidence. Despite widespread non-medical use as an injectable, controlled clinical evidence for systemic injection of GHK-Cu in humans is essentially absent. Most claimed effects from injection derive from extrapolation of topical/in vitro evidence and animal injection studies.
- Regulatory status splits by route. Approved as Copper Tripeptide-1 for topical cosmetic use in most major jurisdictions (US, EU, Canada, Asia). Not FDA-approved as an injectable pharmaceutical. Some FDA-cleared topical wound-care products contain GHK-Cu. Research chemical injectable forms exist in legal grey area. WADA status: Not currently prohibited.
Legal status
Legal status
Approved as cosmetic ingredient (Copper Tripeptide-1) for topical use in most major jurisdictions. Not FDA-approved as injectable pharmaceutical. Some FDA-cleared topical wound-care products contain GHK-Cu. Sold through cosmetic channels (topical) and unregulated sources (injectable form). Not a controlled substance. Not WADA-prohibited.