GHK-Cu
Copper-coordinated tripeptide (Gly-His-Lys + Cu²⁺)
- Class
- Copper peptide
- Half-life
- Minutes to ~2 hours (rapid plasma clearance; tissue effects persist longer)
- Route
- —
- Cadence
- Daily
- Evidence
- Mixed / early human
Overview
GHK-Cu is a tripeptide (three amino acids — glycine, histidine, lysine) bound to a copper atom. Your body actually makes the unbound tripeptide naturally in your blood, and the levels drop as you age. Bound to copper, it becomes the form that's used in skincare and research.
Skin is where the evidence is strongest. Topical GHK-Cu — used in serums and creams — has been shown in published human studies to increase collagen production, improve skin elasticity, reduce fine lines, and speed up wound healing. It's the active ingredient in several approved cosmetic products. This is the one peptide on this list where the cosmetic-tier evidence is genuinely solid.
Injected (subcutaneous) use is a different story. Some people use it for broader regenerative effects (hair, lung tissue, bone) based on animal studies, but the human evidence for systemic effects is thin. Topical is the well-trodden path; subcutaneous is more experimental.
Safety considerations
A few of the safety signals worth knowing — the full list, with dosing context and what to monitor, is inside AIx Core.
- Topical use is genuinely well-tolerated — rare contact sensitivity is about the only common issue.
- Don't layer it with high-concentration vitamin C or strong acids in the same skincare routine — they destabilise the copper complex and you lose the benefit.
- remove (if entry is topical-only) OR keep if route is corrected to topical/subq
+ 2 more safety notes inside AIx Core →
Commonly monitored
Markers and signals people track when researching GHK-Cu.
- Skin appearance — photos in the same lighting once a month is the best objective measure
- Hair density / shedding if using for hair (also takes 3-6 months to see anything)
- Copper / ceruloplasmin blood levels — only if you're using it systemically long-term
- remove (if entry is topical-only) OR keep if route is corrected to topical/subq
Frequently asked questions
What is GHK-Cu?
Copper-coordinated tripeptide (Gly-His-Lys + Cu²⁺). GHK-Cu is a tripeptide (three amino acids — glycine, histidine, lysine) bound to a copper atom. Your body actually makes the unbound tripeptide naturally in your blood, and the levels drop as you age. Bound to copper, it becomes the form that's used in skincare and research.
How is GHK-Cu administered?
—, typically daily.
What is the half-life of GHK-Cu?
Minutes to ~2 hours (rapid plasma clearance; tissue effects persist longer) — Topical absorption is the main story — skin sees the most.
Is GHK-Cu approved for human use?
GHK-Cu is investigational — not approved by the FDA, EMA, or MHRA for human use at the time of writing.
What does the evidence show for GHK-Cu?
Evidence tier: Mixed / early human. Pickart 2018 (the most comprehensive review) summarises ~30 years of research — Loren Pickart is one of the original discoverers, which is worth keeping in mind when reading the conclusions.
What is commonly monitored when researching GHK-Cu?
Commonly tracked markers + signals: Skin appearance — photos in the same lighting once a month is the best objective measure, Hair density / shedding if using for hair (also takes 3-6 months to see anything), Copper / ceruloplasmin blood levels — only if you're using it systemically long-term, remove (if entry is topical-only) OR keep if route is corrected to topical/subq.
Related compounds
Open this in AIx Core for the full picture
Mechanism breakdown, receptor pathway diagram, full safety list, monitored items, source citations, and one-tap add-to-protocol. Free with any account.