GHK-Cu Half-Life: What the Research Shows
No plasma half-life figure for GHK-Cu has been published in humans: the one formal pharmacokinetic study we could find gave GHK intravenously to rats and reported that it was rapidly broken down to the dipeptide HK, which was itself eliminated rapidly (Endo et al., J Chromatogr B, 1997). In people, GHK is a natural part of blood plasma, at about 200 ng/mL at age 20 and 80 ng/mL by age 60 (Pickart and Margolina, Int J Mol Sci, 2018), and on human skin the copper complex builds a depot in the tissue. This page sets out what is and is not published, and how half-life differs from how long a vial or GHK-Cu Nasal Spray keeps.
Findings
- GHK (glycyl-histidyl-lysine) occurs naturally in human plasma, at about 200 ng/mL at age 20, declining to 80 ng/mL by age 60 (Pickart and Margolina, 2018).
- After intravenous injection in rats, GHK was rapidly degraded to HK, and the method needed a protective agent in plasma samples to stop breakdown before measurement (Endo et al., 1997).
- In blood, GHK-Cu forms two ternary copper complexes with human serum albumin, a likely transport form (Bossak-Ahmad et al., 2021).
- On human skin in the laboratory, 136 µg/cm² of copper permeated over 48 hours and 97 µg/cm² stayed in the skin as a depot (Hostynek et al., 2011).
View product →What is GHK-Cu?
GHK is a tripeptide, three amino acids long, that binds copper(II) tightly to form GHK-Cu. Since its discovery in 1973 it has been studied for skin and tissue repair; a 2018 review describes it stimulating blood vessel and nerve outgrowth, raising collagen, elastin and glycosaminoglycan synthesis, and supporting dermal fibroblasts, with gene data suggesting why one small molecule has such varied effects (Pickart and Margolina, Int J Mol Sci, 2018). Its blue colour comes from the bound copper, explained in Why GHK-Cu is blue, and the skin studies are in GHK-Cu: the skin research.
What does half-life mean?
A half-life is the time it takes for the concentration of a compound in the blood to fall by half. It is measured by giving a known amount by a known route and sampling repeatedly as levels fall. For a molecule the body already makes, like GHK, there is a second complication: the measured level is the sum of the body’s own supply and anything added, so a formal study has to separate the two. Figures quoted online without a primary source are not used here.
What has been published about GHK in the body?
Natural plasma levels
GHK was first identified in human plasma, and its concentration changes with age: about 200 ng/mL (10-7 M) at age 20, falling to 80 ng/mL by age 60 (Pickart and Margolina, 2018). That decline is one reason the peptide is studied in ageing skin and tissue.
The rat pharmacokinetic study
Researchers in Japan developed a sensitive HPLC method to measure GHK and its breakdown product, the dipeptide L-histidyl-L-lysine (HK), in rat plasma, with detection limits of 50 and 15 ng/mL. Plasma samples needed o-phenanthroline, a metal-binding agent, to protect GHK from degrading before it was measured. Applied to a single intravenous injection in rats, the method showed GHK was rapidly degraded to HK, which was itself eliminated rapidly (Endo et al., J Chromatogr B, 1997). The abstract describes the pattern rather than giving a single half-life number.
Copper, albumin and transport
GHK is found at its highest concentration in the albumin-rich fraction of plasma. A 2021 study showed that GHK-Cu forms two ternary complexes with human serum albumin, one at the histidine in position 3 of albumin, and proposed that these complexes help carry exchangeable copper and the functional form of GHK in the blood (Bossak-Ahmad et al., Inorg Chem, 2021).
What did the research show on human skin?
For a peptide used on skin, the more relevant question is often how much reaches and stays in the tissue. In flow-through diffusion cells using human skin, a 0.68% aqueous copper tripeptide solution was applied for 48 hours. Copper permeated dermatomed skin with a permeability coefficient of 2.43 × 10-4 cm per hour; 136.2 µg/cm² permeated over 48 hours, while 97 µg/cm² was retained in the skin as a depot. The authors concluded that copper as the tripeptide was delivered in potentially therapeutically effective amounts for inflammatory disease (Hostynek et al., Inflamm Res, 2011).
What is and is not published
| Question | Finding | Source |
|---|---|---|
| Human plasma half-life | Not published | No human PK study |
| Rat, intravenous | Rapidly degraded to HK | Endo, 1997 |
| Natural human levels | About 200 ng/mL at 20, 80 at 60 | Pickart, 2018 |
| Human skin, in vitro | Permeates, with a skin depot | Hostynek, 2011 |
For other repair peptides, see BPC-157 half-life, BPC-157 vs GHK-Cu and KPV vs GHK-Cu.
What does this mean for study design?
The published work points to three practical lessons. First, GHK breaks down quickly in plasma samples, so the 1997 method protected samples with a metal-binding agent before analysis; sample handling is part of the result. Second, because the body makes GHK, baseline levels need measuring, and they vary with age. Third, for skin research, tissue retention and permeation over hours are the useful measures, as the 48-hour diffusion study showed. Published pharmacokinetic work covers intravenous injection in rats and skin in the laboratory; other routes, including intranasal, are research questions in their own right.
Half-life in the body vs how long a vial or spray keeps
Half-life describes the peptide inside a living system. Shelf life describes the product: how long a lyophilised (freeze-dried) GHK-Cu vial keeps before and after mixing, and how long a ready-mixed nasal spray keeps once opened. Those depend on temperature, light and handling, and are covered in How long does GHK-Cu last?, GHK-Cu stability and How to store a peptide nasal spray. Vials are reconstituted with bacteriostatic water (see the GHK-Cu reconstitution guide), and certificates for every product are on the lab reports page.
GHK-Cu is supplied for laboratory research use only. The pharmacokinetic work above is laboratory research.
Frequently asked questions
What is the half-life of GHK-Cu?
No plasma half-life for GHK-Cu has been published in humans. In the one rat study we found, intravenous GHK was rapidly degraded to the dipeptide HK, which was eliminated rapidly.
How much GHK is naturally in human blood?
About 200 ng/mL at age 20, declining to 80 ng/mL by age 60, according to a 2018 review.
What did research show about GHK-Cu on human skin?
In a laboratory study on human skin, 136.2 µg/cm² of copper from the tripeptide permeated over 48 hours and 97 µg/cm² was retained in the skin as a depot.
How is GHK-Cu carried in the blood?
GHK is found mainly in the albumin-rich fraction of plasma, and a 2021 study showed GHK-Cu forms two ternary copper complexes with human serum albumin.
Is half-life the same as how long GHK-Cu lasts in the vial?
No. Half-life describes the peptide inside a living system. How long a vial or ready-mixed nasal spray keeps depends on storage temperature, light and handling, covered in the GHK-Cu storage guide.
Sources: Endo T et al. Simultaneous determination of glycyl-L-histidyl-L-lysine and its metabolite, L-histidyl-L-lysine, in rat plasma by high-performance liquid chromatography with post-column derivatization. J Chromatogr B Biomed Sci Appl. 1997. PMID 9187381. Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018. PMID 29986520. Bossak-Ahmad K et al. Ternary Cu(2+) complexes of human serum albumin and glycyl-L-histidyl-L-lysine. Inorg Chem. 2021. PMID 34730942. Hostynek JJ et al. Human skin penetration of a copper tripeptide in vitro as a function of skin layer. Inflamm Res. 2011. PMID 20721598.
More on this: Buy GHK-Cu in Canada and GHK-Cu Side Effects.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
References
The stronger human GHK-Cu evidence is topical and wound-related. It does not establish effects for systemic or injectable use, and one randomised cosmetic study found no objective advantage.
- Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copperMulticentre randomised, evaluator-blinded, placebo-controlled trial; topical GHK-Cu in diabetic neuropathic ulcers.
- Effects of topical copper tripeptide complex on CO2 laser-resurfaced skinRandomised trial after CO2 laser resurfacing; 13 patients completed. No significant objective advantage found for erythema, wrinkles or overall skin quality.
Links open the study record on PubMed so the source can be checked directly. Listing a study is not a claim that its findings apply to any other use, product or route of administration. Research use only.
