We use essential cookies (authentication, your saved goals/stack) by default. With your permission we’ll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Copper Tripeptide-1 (Glycyl-L-Histidyl-L-Lysine:Copper)
A naturally occurring copper-binding tripeptide used in topical skincare for collagen support and skin repair. Honest appraisal: the believable human evidence is TOPICAL/cosmetic — and even there it's thin and mostly formulation-level (e.g. one small RCT after laser resurfacing where patients felt their skin was better but objective measures didn't differ). Most mechanistic claims come from in-vitro and animal work. The injectable use sold on the grey market has no human safety or efficacy data and is research-use-only.
Topical cosmetic peptide — not a dietary supplement
GHK-Cu is a topical cosmetic ingredient, not a supplement you take internally and not a drug. It is sold legally in skincare products to affect the appearance of skin (such as wrinkles). The evidence below comes mostly from small, often industry-funded studies of topical application, so treat the effect sizes cautiously. This page is for transparency and education, not a recommendation.
What the evidence says
Most GHK-Cu studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 2000–2018.
Based on 11 studies · 1 RCT
Confidence
Low confidenceBy outcome
The only controlled human study is a tiny post-laser RCT (n=13) showing improved patient satisfaction but no objective skin change; nearly all other support is in-vitro and animal mechanism, with no data for injectable use.
2 trials ongoing or recruiting · 1 completed on ClinicalTrials.gov
Registered trials show research momentum for GHK-Cu, not proof of effect — a registration is a plan, and posted results are sponsor-reported, not peer-reviewed. They are never counted toward the evidence rating above.
Browse these trials on ClinicalTrials.govClinicalTrials.gov · as of Aug 2026
GHK-Cu (glycyl-L-histidyl-L-lysine bound to copper(II), 'copper tripeptide-1') is a small endogenous peptide found in human plasma that binds copper with high affinity. It is a long-standing cosmetic ingredient: topically it is used in serums and creams marketed for skin firmness, fine lines, and post-procedure repair.
The honest evidence split matters here. (1) TOPICAL/cosmetic: there is real but limited human data.
The best-controlled human study is a small randomized trial in patients after CO2 laser resurfacing — a GHK-Cu skincare regimen produced significantly higher patient-rated skin-quality satisfaction, but blinded objective assessment found no significant difference in erythema, wrinkles, or skin quality versus the control regimen.
Other human reports use multi-ingredient cosmetic formulations, so the GHK-Cu-specific contribution is hard to isolate.
(2) MECHANISM: a substantial body of in-vitro and animal work shows GHK-Cu stimulates collagen, decorin, and glycosaminoglycan synthesis, modulates matrix metalloproteinase (MMP-2/TIMP) expression in dermal fibroblasts, supports keratinocyte/stem-cell proliferation, and — in gene-expression (Connectivity Map) analyses — shifts disease-associated transcriptional patterns toward tissue-repair programs.
Animal models report improved wound/scald healing and antifibrotic effects. These are mechanistically interesting but are preclinical. (3) INJECTABLE: GHK-Cu is increasingly sold for subcutaneous or intramuscular injection for 'anti-aging' and systemic repair.
There are NO human trials of injectable GHK-Cu, no human safety data, and copper-loading carries real toxicity concerns; this use is unapproved, research-use-only, and additionally exposed to grey-market sourcing/purity risk.
Overall: defensible low/emerging evidence for the evidenced topical cosmetic use; essentially unsupported for injectable use.
GHK chelates copper(II) with an affinity similar to the copper-transport site on albumin, forming GHK-Cu — proposed to deliver copper to skin cells and influence copper-dependent enzymes.
In fibroblast cultures and animal wounds GHK-Cu stimulates type I collagen, decorin, and glycosaminoglycan production, and modulates MMP-2 / TIMP expression involved in matrix remodeling.
Connectivity-Map and microarray analyses report GHK can shift disease-associated gene-expression signatures (e.g. emphysema, nervous-system aging) toward tissue-repair patterns — preclinical/computational evidence.
In-vitro and animal work reports radical-scavenging, carbonyl-quenching, and anti-inflammatory effects; not demonstrated as clinical outcomes in humans.
How GHK-Cu works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Avoid — no human trials, no safety data, copper-toxicity and grey-market purity risk. Research-use-only.
Avoid copper-delivering products entirely.
Not studied — avoid beyond ordinary cosmetic topical use, and avoid injectable use entirely.
Patch test topical products and introduce slowly.
Layering with strong actives (retinoids, AHAs/BHAs, vitamin C) may increase irritation for some users; theoretical and product-dependent, not a systemic interaction.
GHK-Cu delivers copper; in anyone managing copper balance (e.g. Wilson's disease therapy), copper-containing products should be avoided. Most relevant to injectable/systemic exposure.
Tip: Patch test; reduce frequency or concentration; avoid layering with other irritants
Tip: Discontinue if rash or itching develops
Tip: Do not inject; no human safety data and copper-loading carries real toxicity risk
GHK-Cu has an evidence score of 3/10 — emerging evidence based on 11 indexed studies. A naturally occurring copper-binding tripeptide used in topical skincare for collagen support and skin repair. Honest appraisal: the believable human evidence is TOPICAL/cosmetic — and even there it's thin and mostly formulation-level (e.g. one small RCT after laser resurfacing where patients felt their skin was better but objective measures didn't differ). Most mechanistic claims come from in-vitro and animal work. The injectable use sold on the grey market has no human safety or efficacy data and is research-use-only. Representative study: PMID 16847171.
The commonly studied dose of GHK-Cu is Topical cosmetic use only: leave-on serums/creams typically 1-2% GHK-Cu (≈0.05-0.2% in some formulas), applied once or twice daily. No validated systemic dose exists.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Timing is flexible for GHK-Cu — consistent daily use matters more than the time of day. Topical cosmetic peptide applied to clean skin once or twice daily; not ingested.
GHK-Cu should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are local skin irritation / redness (topical), contact sensitivity / allergic reaction (topical), unknown systemic effects (injectable). Use caution if any of these apply to you: Injectable/systemic use (no human safety data; copper-toxicity risk); Wilson's disease or other copper-overload disorders (avoid copper-delivering products); Pregnancy/breastfeeding (not studied).
Argireline
Mostly mechanism / observationalA topical cosmetic peptide — a leave-on skincare ingredient, NOT something you swallow, inject, or take as a supplement, and NOT a drug. Argireline (acetyl hexapeptide-8, also sold as acetyl hexapeptide-3) is a six-amino-acid fragment modelled on the SNAP-25 protein. It is marketed as 'topical Botox' because, in cell systems, it interferes with the SNARE complex that nerve endings use to release neurotransmitter, in theory slightly relaxing the tiny muscle contractions that create expression lines. There ARE real human topical studies — small, short, vehicle-controlled split-face wrinkle trials — and they do show modest reductions in the appearance of fine lines. But the effect sizes are small, several of the trials are industry-linked, and this is a cosmetic effect on wrinkle APPEARANCE, not a health outcome. It is generally well tolerated on skin. This entry exists to describe a cosmetic ingredient honestly, not to recommend an ingestible supplement.
Matrixyl
Mostly mechanism / observationalA topical cosmetic peptide — a leave-on skincare ingredient, NOT something you swallow, inject, or take as a supplement, and NOT a drug. Matrixyl is palmitoyl pentapeptide-4 (pal-KTTKS), a fatty-acid-attached fragment of type I collagen; the popular 'Matrixyl 3000' blend pairs palmitoyl tripeptide-1 with palmitoyl tetrapeptide-7. Rather than relaxing muscle like Argireline, Matrixyl is a 'signal peptide' marketed to nudge skin fibroblasts to make more collagen and extracellular matrix. There ARE real human topical studies — most notably a 12-week, double-blind, placebo-controlled, split-face trial that found modest but significant reductions in fine-line appearance — alongside in-vitro work showing it raises collagen/ECM genes. But the human effect sizes are small, several trials are industry-linked or null, and this is a cosmetic effect on skin APPEARANCE, not a health outcome. It is generally well tolerated on skin. This entry describes a cosmetic ingredient honestly, not an ingestible supplement.
Sunscreen (SPF)
Mostly mechanism / observationalDaily broad-spectrum sunscreen — the single most evidence-based anti-aging skincare step there is, and the one most 'anti-aging' actives are really just trying to compensate for. The honest framing: this is the only topical on this list backed by a proper randomized controlled trial for skin aging itself. In the landmark Hughes 2013 trial (n=903), people randomized to daily sunscreen showed 24% less photoaging over 4.5 years — and no detectable increase in skin aging at all — while the mechanism (UV → matrix-metalloproteinase activation → collagen breakdown) is textbook. The same trial cohort also had less skin cancer. The honest caveats: the benefit is overwhelmingly prevention, not reversal of existing damage; real-world results depend entirely on applying enough and reapplying; and chemical (organic) UV filters are systemically absorbed above an FDA testing threshold (clinical significance unknown — mineral zinc-oxide/titanium-dioxide filters sidestep this). If you do one thing for your skin, it's this.
Semaglutide
Mostly mechanism / observationalAn FDA-approved GLP-1 receptor agonist (Ozempic/Rybelsus for type 2 diabetes, Wegovy for chronic weight management) with genuinely strong, large-RCT evidence for glycemic control and substantial weight loss, plus a cardiovascular-outcomes benefit. Honest appraisal: this is a real prescription medicine with real efficacy AND real risks — a boxed warning for thyroid C-cell tumors, pancreatitis and gallbladder risk, very common GI side effects, and growing concern about grey-market/compounded versions. It is included here for reference only, not as a supplement and not auto-recommended.
Explore: Best supplements for Skin, Hair & Beauty
Reviewed by Dr. Baher Al Hakim · Last reviewed June 2026 · evidence from 11 studies · how we score · editorial policy
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
Tap node to isolate • Pinch to zoom • Tap edge for research