GHK-Cu Metabolism and Energy Expenditure: What the Evidence Actually Shows

Does GHK-Cu raise metabolism in people?

The question is unanswered. The proposed mechanisms come from laboratory and animal work, and the human trials found measured skin and wound outcomes, not metabolic ones.

A 2026 systematic review searched the GHK-Cu literature from 2005 to 2026 and retained 64 records; its authors describe the human literature as thin and fragmented, with most randomized trials small and run on facial cosmetic creams [7].

What the laboratory research covers

GHK is a natural tripeptide found in human plasma, saliva and urine, with levels reported to decline with age, and it is proposed that GHK works as a copper complex [1]. The review describes collagen and proteoglycan production, metalloproteinase modulation, attraction of immune and endothelial cells to injuries, and wound healing in dogs, rats, mice and pigs. These findings are preclinical or proposed mechanisms, and none concerns human energy expenditure or thermogenesis [1]. The same review states GHK can up- and downregulate at least 4,000 human genes [1]; a gene-expression finding is not a measurement of energy use or heat production in a person.

What the human trials actually measured

The two human randomized trials found measured skin and wound outcomes rather than metabolism [4][5].

The first trial, published in 2006, randomized patients whose skin around the mouth had been resurfaced with a CO2 laser to skin care with or without GHK-Cu [4]. Thirteen patients completed it [4]. Computer analysis and blinded evaluators found no significant difference in redness resolution, wrinkles or overall skin quality; a patient questionnaire did show a significant difference in overall skin quality favoring GHK-Cu (P=.04) [4].

In the second trial, published in 1992, 86 evaluable patients with venous stasis ulcers completed treatment [5]. A 0.4% tripeptide copper complex cream was no different from an inert vehicle placebo on ulcer size, while silver sulfadiazine 1% reduced ulcer size [5].

Regulatory status

No FDA-approved drug is known to contain GHK-Cu [2][3]. Copper peptide serums and creams are sold as cosmetics, which do not need FDA approval before sale; a product claiming to treat disease or change the structure or function of the body is legally a drug [8]. Non-injectable GHK-Cu sits in category 1 of FDA's interim policy for substances nominated for state-licensed compounding, still under evaluation for the pharmacy bulks list, and FDA has said it intends to consult its Pharmacy Compounding Advisory Committee about it before the end of February 2027 [2][9]. Injectable GHK-Cu appears in FDA's nominated-but-withdrawn table, where FDA cites immunogenicity risk from aggregation and peptide-related impurities and limited human data to inform safety-related considerations [6]. No adverse-event rates were found in the two trial reports [4][5].