LongevityGHK-CuCopper peptide

GHK-Cu

Q: What is GHK-Cu?

GHK-Cu (copper tripeptide-1) is a naturally occurring human tripeptide — glycine–histidine–lysine — bound to a copper(II) ion. It is found in human plasma and is widely used as a 'copper peptide' ingredient in anti-aging skincare. Its best-documented actions are stimulation of collagen and other skin-matrix components in cultured fibroblasts.

Q: Does GHK-Cu actually work for skin and anti-aging?

There is a real mechanistic basis in cultured skin cells (collagen/elastin/matrix synthesis) and supportive but low-tier topical cosmetic studies reporting firmer, clearer skin. The important caveats: most of that human evidence is from small, often industry-sponsored topical studies, and the broader regenerative claims come largely from one research group. The topical skin-remodeling story is the part the literature best supports.

Q: Can you inject GHK-Cu as an anti-aging peptide?

There is no primary published human or animal evidence for injected, systemic GHK-Cu as an anti-aging treatment. The registered clinical trials and cosmetic studies are topical, not injectable, and no validated human pharmacokinetics for an injected dose exists. The injectable-systemic framing is a marketing extrapolation that the published literature does not support.

Q: Does GHK-Cu really change the activity of thousands of genes?

A widely cited transcriptomic analysis reported that GHK shifts the expression of roughly 4,000 genes in cultured human cells, including up-regulation of DNA-repair pathways. That result is from cells in a dish, not from living humans, and should be read as a hypothesis-generating in-vitro finding rather than a demonstrated clinical effect.

Q: Is it true that GHK levels in the blood fall with age?

A commonly repeated figure puts plasma GHK at around 200 ng/mL at age 20, declining to around 80 ng/mL by age 60. That figure is real but is review-sourced — it traces to Pickart's own narrative rather than to an independently located primary publication — so it is presented here as a frequently cited claim rather than a firmly established measurement.

Copper-binding tripeptide · skin & tissue remodeling

GHK-Cu (copper tripeptide-1) is a small, copper-carrying tripeptide — glycine–histidine–lysine chelated to a copper(II) ion — that occurs naturally in human plasma and has become one of the most popular ingredients in 'anti-aging' skincare. In the laboratory it does striking things: in cultured human skin fibroblasts it stimulates the synthesis of collagen, elastin, and other building blocks of the skin's matrix, and a widely cited transcriptomic analysis reported that it shifts the activity of thousands of human genes in cultured cells. Those mechanistic findings, together with small topical cosmetic studies, are the basis for its reputation. But two honesty points define this page. First, almost all of that evidence is either in a test tube (cultured cells) or from low-percentage topical creams and gels applied to the skin — and most of the foundational reviews are written by the same researcher who discovered the molecule. Second, there is essentially no primary published evidence for the popular practice of injecting GHK-Cu as a systemic 'anti-aging peptide': the registered clinical trials and cosmetic studies are topical, not injectable, and no rigorous human pharmacokinetics or half-life has ever been published. This page documents what the literature actually supports — a topical and in-vitro skin-remodeling story — and is explicit about where the injectable narrative outruns the evidence.

The short version

GHK-Cu is a tiny peptide — just three amino acids — that carries a single atom of copper. Your own blood contains it naturally, and the amount is said to fall as you get older (though that exact figure traces back to one researcher rather than to independent measurement).

In lab dishes of human skin cells it switches on the production of collagen and other materials that keep skin firm and elastic, and in animal studies it helps wounds heal. That is why it became a star ingredient in anti-aging face creams and serums.

Here is the important part. Nearly all the supportive evidence is either from cells in a dish or from low-strength creams and gels rubbed onto the skin — and the studies that exist are mostly small, and often run either by the company selling the product or by the scientist who discovered the molecule. That doesn't make the findings wrong, but it means the evidence is narrower than the marketing suggests.

The popular idea of injecting GHK-Cu as a body-wide 'anti-aging shot' is not backed by published human research: the real registered trials and cosmetic studies are topical, not injectable, and no one has published a reliable measurement of how long an injected dose lasts in the body. This page sticks to what is actually documented and flags where the injectable story runs past the evidence.

Molecular identity

Specs

Monoisotopic mass: 402.10768 Da (GHK-Cu complex cation)

Molecular weight: 402.92 g/mol (GHK-Cu complex cation); free GHK peptide is 340.38 g/molPubChem CID 71587328 / 73587
Molecular formula: C₁₄H₂₃CuN₆O₄⁺ (GHK-Cu complex cation); C₁₄H₂₄N₆O₄ (free GHK)PubChem CID 71587328 / 73587
Sequence: Gly-His-Lys (glycyl-L-histidyl-L-lysine) — 3 AA tripeptide, chelated to Cu(II)PubChem CID 73587
Structure / class: Copper(II) tripeptide complex (INCI Copper Tripeptide-1); the Cu(II) chelate of GHK, not a covalent compoundPubChem CID 71587328; INCI
Copper coordination: 1:1 Cu(II) chelate — copper held by the histidine imidazole N, the N-terminal amine, and the deprotonated glycyl amide NCopper-peptide coordination chemistry; PubChem CID 71587328
CAS / UNII: 89030-95-5 · 6BJQ43T1I9 (GHK-Cu complex); free GHK has its own CAS 49557-75-7PubChem CID 71587328 / 73587
PubChem CID: 71587328 (GHK-Cu, 'Prezatide copper') · 73587 (free GHK)PubChem
Water solubility: Water-soluble; highly hydrophilic (free GHK computed XLogP −4.4, TPSA 176 Å²)PubChem CID 73587 (computed properties)
Origin: Endogenous human plasma tripeptide; first isolated by Pickart (1973)Research literature
Molecular target: No classic receptor — copper(II) binding & transport; signals dermal-fibroblast extracellular-matrix (collagen/elastin) synthesis in vitroResearch literature
Half-life: No validated human injectable pharmacokinetics published; free GHK expected short-lived in plasma (copper exchange with albumin/ceruloplasmin + peptidase cleavage)Not established (mechanistic expectation only)
Regulatory status: Cosmetic ingredient (INCI 'Copper Tripeptide-1'); not an approved drug; no approved injectable indicationINCI / FDA

Plain English

Mechanism

GHK (glycyl-L-histidyl-L-lysine) is a naturally occurring human tripeptide — a chain of just three amino acids — first isolated from plasma (the liquid part of blood) by Pickart in 1973. Its defining biochemical property is a very high affinity for copper(II): the histidine and the terminal amine grip a single Cu²⁺ ion (a copper atom carrying a positive charge) to form the GHK-Cu complex, and the peptide is proposed to act as a physiological carrier that shuttles copper to cells. PubChem catalogs the free peptide (CID 73587) and the copper complex separately (CID 71587328, named 'Prezatide copper'), the latter as the Cu(II) chelate (copper held in a molecular claw) rather than a covalent compound (one bonded by shared electrons).

The best-characterized biological actions are in skin connective tissue and are drawn from in-vitro (test-tube / cell-culture) and animal work. In cultured human dermal fibroblasts — the skin cells that build and repair connective tissue — GHK-Cu stimulates synthesis of collagen and elastin (the proteins that make skin firm and stretchy), along with glycosaminoglycans, decorin, and other proteoglycans (the gel-like fillers and scaffolding molecules of the dermis) — together the structural matrix of the dermis (the living layer of skin beneath the surface). In wound-healing models it is reported to promote re-epithelialization (the regrowth of the skin's outer layer over a wound) and angiogenesis (the growth of new blood vessels), and it shows antioxidant and anti-inflammatory activity in cell systems. These are the findings that underlie its 'skin-remodeling' reputation; importantly, they are predominantly cultured-cell and animal data rather than controlled human outcomes.

A frequently quoted claim is that GHK shifts the expression of (switches on or off) roughly 4,000 human genes — up-regulating (turning up) DNA-repair pathways and down-regulating (turning down) inflammatory and metastasis-associated genes. That figure comes from a transcriptomic analysis (a method that reads which genes are switched on across the whole genome at once) performed in cultured human cell lines. It describes gene-expression changes in cells in a dish, not a measured effect in living humans, and should be read as a hypothesis-generating in-vitro result rather than a clinical one.

One caveat frames the entire mechanism literature: the great majority of the GHK-Cu review corpus is authored by Pickart and Margolina — Pickart being the molecule's discoverer. The underlying in-vitro and animal experiments are real, but the synthesis of them into a broad regenerative narrative rests heavily on a single research program, and independent replication of the wider claims is comparatively thin. Critically, none of this mechanistic work establishes that injected, systemic GHK-Cu produces anti-aging effects in humans — that step is an extrapolation, not a demonstrated result.

Sources:PubChem CID 73587 PubChem CID 71587328 PMID 8227353 PMID 18644225 PMID 26236730 PMID 29986520

Why people reach for it

Potential benefits

GHK-Cu is the copper peptide people reach for on skin and tissue remodeling — its appeal rooted in real lab biology, with the honest line that the strong evidence is topical and in-vitro, not injectable. Here's what draws them to it.

Smoother, firmer-looking skin — Its headline draw. In cultured human skin cells GHK-Cu switches on the synthesis of collagen, elastin, and the dermis's matrix — the basis for its reputation as an anti-aging skincare ingredient (best supported topically and in-vitro, not as an injection).
Tissue repair and wound healing — In wound models GHK-Cu promotes regrowth of the skin's outer layer and the growth of new blood vessels, which is why it's reached for around healing, procedures, and connective-tissue recovery.
Copper delivery for stronger tissue — GHK-Cu carries copper into cells, feeding lysyl oxidase — the enzyme that cross-links collagen and elastin into durable tissue — so the appeal is better tissue quality, not just more collagen.
Antioxidant and calming activity — In cell systems it shows antioxidant and anti-inflammatory activity, part of the broader skin-resilience story people pursue it for (reported in vitro, not a proven human outcome).
A remodeling base that stacks well — Because it works on the matrix-building lever, it pairs cleanly with repair peptides that come from other angles — most commonly BPC-157 and TB-500 for a fuller tissue-repair push.

Sources:PMID 8227353 PMID 18644225 PMID 26236730 PMID 29986520

What people reach for GHK-Cu for, drawn from its skin-remodeling mechanism (predominantly cultured-cell and topical evidence, much of it from one research group) and how it's used — not proven outcomes. There is no primary evidence for injected, systemic GHK-Cu as an anti-aging treatment. No medical claims.

Implied timing

Best time to dose

Implied best time

Evening

Most people take GHK-Cu in the evening, lining the skin- and tissue-remodeling signal up with the body's overnight repair window (morning is also fine).

GHK-Cu's documented job is matrix remodeling — signaling fibroblasts to lay down collagen and elastin — and the skin and connective tissue do most of that rebuilding overnight during sleep, so an evening dose puts the signal in just as that repair window opens.
Its effect is a remodeling signal rather than an acute stimulant, so there is no wakefulness reason to favor the morning; aligning it with the overnight repair phase is the more mechanism-consistent lean.
No validated human injectable pharmacokinetics or half-life exists for GHK-Cu, so the timing is reasoned from its remodeling/repair mechanism — not a measured duration of action. A consistent daily time matters more than the exact hour; morning works too.

No study establishes an ideal time of day for GHK-Cu — this is reasoned from its skin- and tissue-remodeling mechanism and how it's used. As a rule of thumb most peptide dosing lands in the midday-to-evening window; for GHK-Cu the lean is evening, to align with overnight repair.

How to run it

Dosing & protocol

GHK-Cu is dosed here as a subcutaneous injection — the form sold as a research peptide and the route the on-page calculator is built for. The community convention runs 1–2 mg/day SC, cycled. Read the numbers below as a map of how people actually run injectable GHK-Cu — not a validated prescription, and not a route the published human trial record supports.

Critical honesty axis: the robust published evidence for GHK-Cu is topical (creams, gels applied to skin) and in-vitro (cultured fibroblast and transcriptomic work). Injectable systemic use is community convention, not trial-proven — no controlled human injectable trial exists, and no validated human pharmacokinetics has been published. Almost all foundational reviews are authored by Pickart, the molecule's discoverer; independent replication of the broader regenerative claims is thin. Every number here is a usage pattern, not evidence.

Tiered dose ranges

Community protocols scale the subcutaneous dose to the goal — skin/tissue remodeling or broader systemic support.

Low / introductory:: 500–750 mcg once daily — first testing tolerance, or a conservative ongoing skin-support dose.
Standard:: 1 mg (1,000 mcg) once daily — the most common community maintenance dose for skin remodeling and collagen signaling goals.
Higher end:: 1.5–2 mg/day — the top of the community range; sometimes split into two 750–1,000 mcg injections. No data establishes additional benefit over 1 mg.

Subcutaneous administration

GHK-Cu is injected into subcutaneous fat; site rotation and timing are the actionable choices.

Injection site:: Abdomen (staying a few centimeters from the navel), outer thigh, or love-handle area. Rotate sites between doses to prevent local irritation and lipohypertrophy (fatty lumps from repeated use of one spot).
Measuring the dose:: Drawn on a U-100 insulin syringe from the reconstituted vial. At the standard mix (50 mg vial + 2 mL BAC water = 25,000 mcg/mL): 1,000 mcg = 4 IU · 1,500 mcg = 6 IU · 2,000 mcg = 8 IU. The on-page calculator handles any vial size.
Time of day:: No peptide-specific timing data exists for injectable GHK-Cu. Most users lean evening to align the remodeling signal with the overnight repair window — see Best time to dose above — though morning is also fine; a consistent daily time matters more than the exact hour. If splitting a larger dose, space ~12 hours apart.
Food window:: Subcutaneous injection; no absorption competition with meals. Inject independent of food.

Cycle & washout

GHK-Cu is typically run in defined cycles rather than indefinitely — consistent with how most peptides in this class are used.

Standard cycle:: 8–12 weeks of daily dosing, then reassess. Some users run shorter 4–6 week blocks.
Washout:: 4-week break between cycles. No GHK-Cu-specific receptor desensitization data exists; the washout is by convention, not demonstrated necessity.
On-demand use:: Some use GHK-Cu in shorter 2–4 week skin-focused pulses (around a procedure, season change, or healing period) rather than a fixed cycle.

Reconstitution at a glance

The on-page calculator does this live; the quick reference for the standard 50 mg vial:

Mixing:: 50 mg vial + 2 mL bacteriostatic water = 25,000 mcg per mL. On a 100-unit (1 mL) insulin syringe: 500 mcg = 2 IU · 1,000 mcg = 4 IU · 1,500 mcg = 6 IU · 2,000 mcg = 8 IU.
Note on the 50 mg vial:: GHK-Cu commonly ships as a 50 mg vial — larger than most peptide vials. At 2 mL BAC water the concentration is high (25,000 mcg/mL), so doses are small syringe fractions. Using 4–5 mL instead brings the concentration down to 10,000–12,500 mcg/mL if you prefer larger unit increments.

Sources:PMID 8227353 PMID 26236730AAD Annual Meeting 2002 (conference presentation)NCT07437586

Substrate the signal needs

Nutritional cofactor precision

GHK-Cu does two mechanistically distinct things: it carries copper into cells and it signals collagen synthesis in dermal fibroblasts. The cofactors below follow those two levers — supply the collagen-building machinery what it needs, and keep copper status healthy rather than accidentally antagonized.

Reasoned from GHK-Cu's copper-carrier and collagen-signaling mechanism — not a GHK-Cu cofactor study. Supplement doses are standard nutritional ranges; the copper/zinc balance point is especially important for this peptide given it already delivers copper.

Supply the collagen substrate

GHK-Cu tells fibroblasts to make collagen and elastin — give them the raw materials to do it.

Vitamin C — 500 mg daily:: Cofactor for prolyl and lysyl hydroxylase, the enzymes that stabilize collagen's triple-helix structure. Without adequate vitamin C, the collagen signal GHK-Cu sends cannot be fully acted on. Timing: with a meal, any time of day.
Hydrolyzed collagen — 10–15 g daily:: Supplies the glycine-proline-hydroxyproline tripeptides that fibroblasts reassemble into new collagen. Collagen synthesis is substrate-limited; signaling more of it without supplying the building blocks is a half-measure. Timing: with vitamin C for potential synergy.
Glycine / proline via diet:: Glycine is the most abundant amino acid in collagen (one-third of all residues). Adequate dietary protein from collagen-rich sources (broth, gelatin) or a glycine supplement (~3–5 g/day) reinforces the substrate pool without a separate product.

Balance the copper angle

GHK-Cu already delivers copper — the copper status nuance here runs the opposite way from most mineral stacks.

Dietary copper — 1–2 mg/day (food-first):: GHK-Cu is a copper carrier, and the copper it delivers feeds lysyl oxidase (the enzyme that cross-links collagen and elastin into strong tissue). Maintaining whole-body copper status via diet (organ meats, shellfish, nuts, legumes) ensures the enzymatic machinery is ready. Supplemental copper is rarely needed unless diet is genuinely deficient.
Zinc 15–30 mg — with copper 1–2 mg pairing:: Zinc is necessary for matrix metalloproteinase (MMP) activity — the remodeling enzymes that clear old collagen before new matrix is laid down. However, zinc and copper compete for intestinal absorption (same divalent-metal transporter), so high-dose zinc supplementation can quietly deplete copper and work against the copper-dependent enzymes GHK-Cu feeds. Balance matters more than dose here: keep zinc at 15–30 mg and explicitly pair it with 1–2 mg copper bisglycinate to prevent depletion. Timing: with a meal, away from iron if possible.

Combinations + timing

Stacking notes + timing windows

GHK-Cu's strongest published mechanism is local: collagen and matrix remodeling in skin and connective tissue. The best injectable stack partners come at tissue repair from a different angle — vascularization, cell migration, or structural rebuild — rather than doubling the collagen signal.

Community combinations reasoned from complementary mechanisms — not regimens studied head-to-head. GHK-Cu itself has no human injectable trial, so any stack is doubly unproven. Doses are community convention; 'reach for' describes where users go, not a proven indication.

GHK-Cu + BPC-157

The most common pairing — GHK-Cu remodels the matrix, BPC-157 heals the tissue and builds the vascular supply.

Why it works:: BPC-157 is studied for accelerating healing across gut lining, tendons, and wound tissue — it drives angiogenesis (growth of new blood vessels) and upregulates growth-factor signaling in injury sites. GHK-Cu works a different lever: stimulating fibroblasts to synthesize the collagen and elastin that fill the repaired space. Together they address both the scaffold (GHK-Cu) and the blood supply and repair-signal (BPC-157) — not the same mechanism twice.
The protocol:: GHK-Cu 1 mg + BPC-157 250–500 mcg, each subcutaneous once daily, rotated sites. Can be drawn separately or co-injected into the same site.
Outcome:: The combination users reach for on skin aging, wound healing, and soft-tissue recovery where both matrix remodeling and vascular repair are goals.

GHK-Cu + BPC-157 + TB-500

The systemic tissue-repair trio — adds cell migration to the matrix-remodel and vascular-repair pair.

Why it works:: TB-500 (Thymosin β4) promotes the migration of repair cells — stem cells, endothelial cells, keratinocytes — into damaged tissue. BPC-157 brings the vascular support; GHK-Cu drives the collagen and matrix synthesis in the space they open. Three distinct jobs, three different levers.
The protocol:: GHK-Cu 1 mg + BPC-157 250–500 mcg daily; TB-500 on its own loading schedule (commonly 5–10 mg/week loading for 4 weeks, then 2.5–5 mg/week maintenance). GHK-Cu and BPC-157 are typically daily; TB-500 is typically weekly or twice-weekly.
Outcome:: Reached for on broader soft-tissue, skin, and connective-tissue repair goals — post-procedure recovery, chronic tendon or fascial injury, systemic skin remodeling.

GHK-Cu + free GHK (GHK (copper-free, Gly-His-Lys))

The copper-free / copper-loaded pair — the same tripeptide backbone, opposite copper states.

Why it works:: Free GHK (glycyl-L-histidyl-L-lysine without copper, GHK (copper-free, Gly-His-Lys)) is the endogenous circulating form the body produces. It binds copper avidly — GHK has one of the highest known affinities for Cu(II) of any naturally occurring peptide — so free GHK is essentially a copper scavenger that converts to GHK-Cu in vivo wherever copper is available. Running both means the free peptide mops up copper from the local environment and converts on-site, potentially extending or complementing the activity of the pre-loaded complex. The relationship between the two is the same molecule at different oxidation states, not a different mechanism.
The protocol:: Community use is exploratory; typical pairings run GHK-Cu 1 mg + free GHK 500 mcg–1 mg SC daily, or alternate the two. No comparative human data exists.
Outcome:: Reached for by users trying to maximize tissue copper delivery and collagen signaling simultaneously. A single-molecule / dual-state combination, not a synergy between two pathways.

Reconstitution math

Reconstitution calculator

Calculated for a 1 mL U-100 insulin syringe (100 units/mL).

Peptide per vial

BAC water added

Desired dose

Units per dose

Draw to this mark on a U-100 syringe

Volume per dose: 0.08 mL
Doses per vial: 25
Concentration: 25 mg/mL

One vial lasts

Daily: 25 days
Every other day: 50 days
5×/week: 35 days

Research use only. Not for human consumption. Outputs are reference values based on research literature — verify all measurements independently.

From the studies

Side effects from research

Within the topical cosmetic studies, GHK-Cu's tolerability was reported as good, with no consistent irritation or sensitization signal of note. That said, no PMID-indexed, controlled human safety dataset for GHK-Cu was located, so the tolerability picture rests on the same small, often industry-run studies that underpin the efficacy claims rather than on dedicated safety trials.

The principal theoretical concern attaches to the copper the molecule carries. Copper is a redox-active metal, and chronic high-dose systemic exposure raises a theoretical risk of copper overload and pro-oxidant effects. There is no human toxicity dataset establishing where, or whether, that risk becomes clinically meaningful for GHK-Cu specifically — it is a mechanistic caution, not a documented harm.

Regulatory status frames the rest: GHK-Cu is recognized as a cosmetic ingredient under the INCI name 'Copper Tripeptide-1' and is not an FDA-approved drug. There is no approved systemic or injectable indication for it anywhere. This page presents the research and cosmetic literature only and makes no therapeutic claim; the gap between that topical/cosmetic evidence base and the injectable 'anti-aging peptide' marketing is the single most important thing to carry away from it.

Sources:AAD Annual Meeting 2002 (conference presentation)PMID 26236730

As reported in literature

Research dosing ranges

These are the concentrations actually used in the published studies — the evidence the practical figures above lean on, shown separately so research data is never mistaken for a recommendation. Unusually for this catalog, the documented human and clinical use of GHK-Cu is TOPICAL (applied to the skin), not injected, so the rows are concentrations of creams and gels rather than per-kilogram injectable doses. Published topical formulations are low-percentage (typically well under 1%). No systemic injected GHK-Cu dose appears in any published human study; the only injected animal data is local intra-wound injection (directly into the wound site) in rats (Maquart 1993), not systemic dosing. The subcutaneous milligram figures circulated by vendors are not literature-derived and are shown here only to be marked as unsupported.

Dose	Route	Model	Outcome	Sources:
0.1% topical gel	Topical	Human — Phase-2 acute-wound-healing trial (recruiting, no results posted)	Registered to test split-wound healing; results not yet available	NCT07437586
Low-percentage facial cream (<1%)	Topical	Human — 12-week cosmetic study (n≈71; conference / industry-sponsored)	Reported improvements in skin firmness, clarity, and density vs comparators; low-tier evidence	AAD Annual Meeting 2002 (conference presentation)
Local intra-wound injection	Injected (local, intra-wound)	Rat — in-vivo experimental wound (foundational mechanism study)	Locally injected GHK-Cu stimulated connective-tissue/collagen accumulation in wound chambers; local delivery, not systemic dosing	PMID 8227353
Injected / systemic dose	Subcutaneous	— none published	No systemic injected GHK-Cu dose appears in any published human study; vendor 'mg SC' figures are not literature-derived

Quick answers

Frequently asked

What is GHK-Cu?

GHK-Cu (copper tripeptide-1) is a naturally occurring human tripeptide — glycine–histidine–lysine — bound to a copper(II) ion. It is found in human plasma and is widely used as a 'copper peptide' ingredient in anti-aging skincare. Its best-documented actions are stimulation of collagen and other skin-matrix components in cultured fibroblasts.

Does GHK-Cu actually work for skin and anti-aging?

There is a real mechanistic basis in cultured skin cells (collagen/elastin/matrix synthesis) and supportive but low-tier topical cosmetic studies reporting firmer, clearer skin. The important caveats: most of that human evidence is from small, often industry-sponsored topical studies, and the broader regenerative claims come largely from one research group. The topical skin-remodeling story is the part the literature best supports.

Can you inject GHK-Cu as an anti-aging peptide?

There is no primary published human or animal evidence for injected, systemic GHK-Cu as an anti-aging treatment. The registered clinical trials and cosmetic studies are topical, not injectable, and no validated human pharmacokinetics for an injected dose exists. The injectable-systemic framing is a marketing extrapolation that the published literature does not support.

What is GHK-Cu's half-life?

No validated human injectable pharmacokinetics or half-life has been published. Biochemically, free GHK is expected to be short-lived in blood because its copper is readily exchanged with albumin and ceruloplasmin and the peptide is cleaved by plasma peptidases — but that is a mechanistic expectation, not a measured value. The specific half-life numbers quoted online trace to vendors, not to primary studies.

Does GHK-Cu really change the activity of thousands of genes?

A widely cited transcriptomic analysis reported that GHK shifts the expression of roughly 4,000 genes in cultured human cells, including up-regulation of DNA-repair pathways. That result is from cells in a dish, not from living humans, and should be read as a hypothesis-generating in-vitro finding rather than a demonstrated clinical effect.

Is it true that GHK levels in the blood fall with age?

A commonly repeated figure puts plasma GHK at around 200 ng/mL at age 20, declining to around 80 ng/mL by age 60. That figure is real but is review-sourced — it traces to Pickart's own narrative rather than to an independently located primary publication — so it is presented here as a frequently cited claim rather than a firmly established measurement.

Primary sources

References

PubChem CID 73587PubChem CID 73587 (glycyl-L-histidyl-L-lysine / GHK; C14H24N6O4, MW 340.38, sequence)
PubChem CID 71587328PubChem CID 71587328 (Prezatide copper / GHK-Cu complex; C14H23CuN6O4+, MW 402.92; Cu(II) chelate)
PMID 8227353Maquart et al., J Clin Invest 1993 (in-vivo: locally injected GHK-Cu stimulates connective-tissue/collagen accumulation in rat wound chambers)
PMID 18644225Pickart, J Biomater Sci Polym Ed 2008 (GHK-Cu in tissue remodeling and wound healing — review)
PMID 26236730Pickart, Vasquez-Soltero & Margolina, Biomed Res Int 2015 (regenerative & protective actions of GHK in skin — review; cites plasma age-decline figure)
PMID 28212278Pickart, Vasquez-Soltero & Margolina, Brain Sci 2017 (GHK gene-expression / nervous-system effects — review)
PMID 29986520Pickart & Margolina, Int J Mol Sci 2018 (GHK gene-expression & regenerative review; ~4,000-gene transcriptomic claim)
NCT07437586Topical GHK-Cu 0.1% gel for acute skin wound healing (Phase 2, recruiting; no results posted)
AAD Annual Meeting 2002 (conference presentation)Leyden, Stephens, Finkey, Appa & Barkovic — facial & periorbital GHK-Cu cream cosmetic studies (industry-sponsored; no PMID located)

Research use only · Not medical advice · Updated 2026-06-01