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GHK-Cu Pharmacokinetics: Absorption, Distribution, Metabolism, and Excretion

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At a glance

  • Microneedle delivery / increased GHK-Cu skin uptake in laboratory and porcine-skin tests; no registered, adequately powered human randomized trial of this route has been published [5]
  • What GHK-Cu is / the copper(II) complex of GHK, a tripeptide found in human plasma, saliva and urine [1]
  • Copper in plasma / ceruloplasmin carries 40 to 70 percent [6]
  • FDA status / no approved GHK-Cu drug; topicals sold as cosmetics; injectables unapproved [7][8]
  • FDA on the injectable form / immunogenicity risk from aggregation and peptide-related impurities [2]
  • Human trials found / two small topical trials, 13 and 86 patients [3][4]

What GHK-Cu is and what has been shown

GHK-Cu is the copper(II) complex of GHK, a tripeptide (glycyl-L-histidyl-lysine) found in human plasma, saliva and urine, with levels reported to decline with age; it is proposed that GHK works as a copper complex [1]. Laboratory and animal work summarized by the researchers who proposed its actions reports collagen and proteoglycan stimulation, metalloproteinase modulation, and faster wound healing in dogs, rats, mice and pigs — proposed mechanisms, not measured human drug levels [1]. A 2026 systematic review kept 64 of 1,247 records and calls the human literature thin and fragmented [5].

Absorption

For skin, microneedle delivery has been shown in vitro and in porcine ex vivo skin to greatly increase GHK-Cu uptake, but that route has not been evaluated in a single registered, adequately powered human randomized trial [5].

For the injectable form, FDA's stated concern is that compounded injectable drugs containing GHK-Cu may pose a risk of immunogenicity from aggregation and peptide-related impurities, and that there are limited data in humans to inform safety considerations [2].

Distribution and copper handling

Ceruloplasmin carries 40 to 70 percent of plasma copper [6]. The FDA label for cupric chloride injection — an intravenous copper salt used in feeding solutions, not GHK-Cu — states that about 7 percent of plasma copper is bound to albumin and amino acids, and that about 93 percent of liver copper is bound to ceruloplasmin [9].

An early cell-culture paper reported that a tripeptide it calls GHL forms copper(II) complexes and enhances copper uptake into cultured hepatoma cells [10]. That is a laboratory observation in cultured cells, not a measured GHK-Cu result in humans.

Metabolism and excretion

No human measurement of how GHK-Cu is metabolized or cleared was found. The label of cupric chloride injection, a different product, states that copper is primarily excreted through the bile into the gastrointestinal tract, where it is not reabsorbed, and is also eliminated through the kidneys, with daily turnover of about 0.5 mg of copper through ceruloplasmin [9]. That label warns of hepatic copper accumulation in cholestasis, biliary dysfunction or cirrhosis and in Wilson disease, and reports acute copper toxicity with oral, intravenous or subcutaneous copper [9]. It covers an intravenous copper salt, not GHK-Cu.

Regulatory status

No FDA-approved drug is known to contain GHK-Cu [7]. Topical copper peptide creams are sold as cosmetics, which do not need FDA approval before sale; a claim to treat disease or change the body's structure or function makes a product a drug [8]. Injectable GHK-Cu is not a cosmetic and is not FDA-approved [8]. Non-injectable GHK-Cu is in category 1 of FDA's list for state-licensed pharmacies and physicians, with a Pharmacy Compounding Advisory Committee consultation planned before the end of February 2027 and no vote taken [7][11]. Compounded drugs are not FDA-approved [12].

HealthRX.com offers a copper peptide cream.

Frequently asked questions

What is the half-life of GHK-Cu?
It is unknown: we found no published human measurement of a GHK-Cu plasma half-life. FDA notes limited human data for the injectable form [2].
Does topical GHK-Cu penetrate the skin?
Microneedle delivery greatly increased GHK-Cu uptake in vitro and in porcine ex vivo skin, but that route has not been tested in a registered, adequately powered human randomized trial [5].
Is GHK-Cu FDA-approved?
No. No FDA-approved drug is known to contain GHK-Cu [7]. Topical copper peptide products are sold as cosmetics, which do not need FDA approval before sale, and injectable GHK-Cu is not FDA-approved [8].
What happens to the copper in GHK-Cu?
What happens to copper after GHK-Cu use has not been measured in humans. Copper generally circulates bound to proteins, but findings for cupric chloride injection cannot establish GHK-Cu's distribution or excretion [6][9].
How is GHK-Cu cleared from the body?
No human measurement of GHK-Cu clearance was found. For copper in general, the cupric chloride injection label, a different product, says copper is primarily excreted through the bile and also eliminated through the kidneys [9].

References

  1. Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. Biomed Res Int. 2015;2015:648108. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration
  2. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks | FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks | FDA
  3. Miller TR, Wagner JD, Baack BR, Eisbach KJ. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. 2006;8(4):252-9. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin
  4. Bishop JB, Phillips LG, Mustoe TA, VanderZee AJ, Wiersema L, Roach DE, et al. A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers. J Vasc Surg. 1992;16(2):251-7. A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers
  5. Najafi N, Maatouk H, Vardanyan KG, Vartanian KB, Agrawal DK. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu (Glycyl-L-Histidyl-L-Lysine-Copper Complex) in Topical Microneedle Delivery: A Case for Expanded Clinical Trials. Arch Intern Med Res. 2026;9(3):269-293. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu (Glycyl-L-Histidyl-L-Lysine-Copper Complex) in Topical Microneedle Delivery: A Case for Expanded Clinical Trials
  6. Linder MC. Ceruloplasmin and other copper binding components of blood plasma and their functions: an update. Metallomics. 2016;8(9):887-905. Ceruloplasmin and other copper binding components of blood plasma and their functions: an update
  7. U.S. Food and Drug Administration. U.S. Food and Drug Administration
  8. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) | FDA. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) | FDA
  9. U.S. National Library of Medicine, DailyMed. COPPER (cupric chloride) prescribing information. COPPER (cupric chloride) label
  10. Pickart L, Freedman JH, Loker WJ, Peisach J, Perkins CM, Stenkamp RE, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature. 1980;288(5792):715-7. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells
  11. Bulk Drug Substances Used in Compounding of the FD&C Act | FDA. Bulk Drug Substances Used in Compounding of the FD&C Act | FDA
  12. Official web page. Official web page
Evidence overview for GHK-Cu Pharmacokinetics: Absorption, Distribution, Metabolism, and Excretion