GHK-Cu: Every Human Study Is a Cream, and It Is Sold in a Vial

01What it is

GHK is three amino acids linked together: glycine, histidine and lysine. It is present in your own body. The "Cu" is a single copper atom the peptide binds and carries, not a mineral stirred into the mix, and copper makes up 15.8 percent of the complex by weight (PubChem CID 165429100). That is a calculation from the molecular weight of 401.91, not a measured value from any paper.

02What the trials found

The one that worked, 1994. A multi centre trial applied a gel to patients with diabetic neuropathic foot ulcers. Assignment was random between the GHK containing gel and the same base with nothing added, and the people measuring did not know which was which. Median wound closure was 98.5 percent with the peptide against 60.8 percent with base. In the ulcers larger than 100 mm² the split was starker: those on the peptide closed by a median 89.2 percent, while the ones on plain base grew, by 10.3 percent. Among patients who started immediately after the ulcer was cleaned, 7 percent got infected against 34 percent on base. (PMID 17147644)

That is a real, controlled, positive finding in humans, and it is the only one. The paper does not state the gel's concentration, so the 2 percent figure on vendor sites is unconfirmed.

1992, leg ulcers. Eighty six patients with venous stasis ulcers received either 1 percent silver sulfadiazine cream, 0.4 percent copper tripeptide cream, or placebo. Blinded evaluators scored the silver cream best for healing. The copper peptide did not beat the fake cream. (PMID 1495150)

2006, thirteen faces. Patients had the skin around the mouth resurfaced with a CO2 laser, then were randomly assigned to the treatment or not. Blinded evaluators and computer analysis of photographs found no difference between groups in how fast the redness settled, or in wrinkles, or in skin texture. (PMID 16847171)

Two more that get quoted are not studies. Leyden's face cream was a conference abstract in February 2002, which does not go through the review a published paper does. Abdulghani's claim that GHK-Cu cream beat vitamin C and retinoic acid in twenty women appeared in a journal PubMed does not index and which I could not locate. Both reach the reader through reviews by Loren Pickart, who isolated the peptide in 1973 and sells copper peptide skincare. (PMID 26236730) The crow's feet trial is one patient given five treatments. (PMID 27064823)

Nobody has published an injection of GHK-Cu into a person. I searched PubMed for GHK-Cu and for glycyl-histidyl-lysine across every route and got twenty two results, all of them animals, cells in dishes, or materials research.

I say could not find rather than does not exist.

Two 2026 reviews on injectable peptides, one in sports medicine (PMID 41476424) and one in orthopaedics (PMID 41490200), landed in the same place: no clinical data, and indication, dose, frequency and duration all unknown. The mechanistic research is real if inconsistent, with rats showing increased connective tissue on experimental wounds (PMID 8227353) and repaired knee ligaments with a benefit the authors themselves called transient (PMID 25731775). The only dose figures naming a species and a route are 15 mg/kg in aged mice. (PMID 42245779)

Check the registry yourself and you will find a fake. ClinicalTrials.gov has five records for "GHK". Only one uses GHK-Cu as the study drug: NCT07437586, a phase 2 study of a gel in 60 healthy adults under "Hudson Biotech" at Peking University Shenzhen Hospital. Do not cite it.

That cluster is not my finding. Morgan McSweeney documented it on 31 July 2026: eight registrations under that sponsor, all at the one hospital, all recruiting, two of them copies of real Eli Lilly obesity trials reusing Lilly's own molecule codes, and Lilly confirmed to him it has no relationship with the sponsor. (Dr Noc) One of the eight carries "(Mock Study)" in its title. This one says nothing, and I read it in full without finding a tell inside it. The tells sit outside the text: the two listed phone numbers run in sequence, and the record claims a data monitoring committee while declaring it is not an FDA regulated drug or device.

Of the rest, NCT05932732 gives a facial serum listing Cu-GHK among its ingredients without isolating it, and NCT07706361 only measures the GHK already in people's blood. No legitimate registered trial gives GHK-Cu on its own.

03The hair paper is about a different molecule

The study cited most often as evidence for GHK-Cu and hair tested AHK-Cu, a copper peptide with alanine in the first position. (PMID 17703734) One letter, and a generic title lets it pass for the other.

04How it compares

Three neighbours, all sold for repair, all in vials.

Read the last column. GHK-Cu has the strongest evidence there and the least portable, because all of it went on the outside of a person.

05Where the dose came from

The consensus is 1 to 2 mg a day under the skin, some say 3. A common protocol is 1 mg daily for two weeks then 2 mg daily for two weeks, or 2 mg three times a week, on an 8 to 12 week cycle with 4 week breaks. You can also find instructions to mix a 50 mg vial with 2 mL of bacteriostatic water for 25 mg/mL, which puts 0.25 mg in each unit on an insulin syringe.

None of this has a published source I could find, not a trial, not a pharmacology study, not anything in humans or animals. One vendor page says as much itself, describing its recommendations as a consensus from a compounding source.

At 25 mg/mL, 1 mg is 4 units, 2 mg is 8, 3 mg is 12. The doses that circulate are the easy marks to read.

06What could go wrong

Whether copper accumulates. A 2 mg dose carries roughly 320 mcg of elemental copper, against a recommended daily intake of 900 mcg and an upper limit of 10,000. Both are dietary figures, and dietary intake is limited by what the gut absorbs and what the liver bothers to excrete. Injecting bypasses both. Those limits exist because chronic over-supplementation has known consequences, and I could find no published work on blood copper, on ceruloplasmin, the blood's copper carrier, or on liver copper in a single human who injected GHK and nothing else.

07What nobody knows

Whether the age decline is real. The most quoted line about GHK is that blood levels run about 200 ng/mL at age 20 and 80 ng/mL by 60, which underwrites the whole restore-what-you-lose sales story. The sentence carries no reference in the peer reviewed article where it appears (PMID 35083444), and I could not find a primary source for it.

Its regulatory status in the United States. Three different FDA pages timed out for me and vendor claims contradict each other, so on the general question I still have nothing to say. FDA did send a warning letter on 1 April 2020, reference 594743, to a compounding pharmacy in Nicholasville, Kentucky, Tailor Made Compounding LLC, and under the heading "Failure to Meet the Conditions of Section 503A" it names the bulk drug substances that firm had been compounding with, GHK-Cu among them, spelled there exactly as it is spelled here. Look it up under that reference number and read what it is. A letter to one pharmacy about that pharmacy's own compounding, turning on eligibility for a statutory exemption rather than on safety or on whether the compound works, and not an action against GHK-Cu itself or against anyone else selling it.

08My take

I think injected GHK-Cu is copper supplementation in disguise, wrapped in a peptide that carries the marketing and a pharmacology I could find no measurement of. The studies that speak for it were rubbed into wounds, and I do not see those findings surviving the trip into the bloodstream past two organs whose job is regulating copper.

What convinces me least is the cherry picking. The one positive cream study is on every vendor page I have seen. The two negative ones are on none of them.

So: has anyone reading this had serum copper and ceruloplasmin drawn before and after starting the injections? I would like to see those numbers.

Frequently asked

Does GHK-Cu actually work?+

Every published human study applies it to skin, and of the three controlled trials, one was positive and two were not. The 1994 trial of a gel on diabetic neuropathic foot ulcers found median wound closure of 98.5 percent against 60.8 percent for the same base with nothing added, and among patients starting right after the ulcer was cleaned, 7 percent got infected against 34 percent on base. The 1992 trial of a 0.4 percent cream on venous stasis ulcers in 86 patients scored silver sulfadiazine best and the copper peptide did not beat the fake cream. The 2006 trial in thirteen patients after CO2 laser resurfacing found no difference in how fast redness settled, or in wrinkles, or in skin texture.

Are there any human studies on injecting GHK-Cu?+

I could not find one, by any route. Searching PubMed for GHK-Cu and for glycyl-histidyl-lysine returned twenty two results, all of them animals, cells in dishes, or materials research. Two 2026 reviews of injectable peptides, one in sports medicine and one in orthopaedics, both landed on no clinical data, with indication, dose, frequency and duration all unknown.

Where does the 1 to 2 mg GHK-Cu dose come from?+

It circulates as convention, not as a finding. The consensus figure is 1 to 2 mg a day under the skin, with some sources saying 3, and I could not connect any of it to a trial, to a pharmacology study, or to anything published in humans or animals. What those numbers do have in common is not pharmacology: at the concentration vendor instructions describe, each lands on an easy mark to read off a syringe.

Can injected GHK-Cu cause copper overload?+

I could not find the measurement published. A 2 mg dose carries roughly 320 mcg of elemental copper, against a recommended daily intake of 900 mcg and an upper limit of 10,000 mcg, but both of those are dietary figures, and dietary intake is limited by what the gut absorbs and what the liver bothers to excrete. Injecting bypasses both. Those limits exist for a reason, and I could find no published work on blood copper, ceruloplasmin or liver copper in a single human who injected GHK and nothing else.

Is GHK-Cu FDA approved?+

On the general question I have nothing to say, because three different FDA pages timed out for me and vendor claims contradict each other. What is on the record is a warning letter FDA sent on 1 April 2020, reference 594743, to a compounding pharmacy in Nicholasville, Kentucky, which named GHK-Cu among the bulk drug substances that firm had been compounding with. The reason given was eligibility for a statutory exemption rather than anything about safety or about whether the compound works, resting on three findings: no applicable USP or NF monograph, not a component of an FDA approved human drug, and not on the 503A bulks list. It is a letter to one pharmacy about its own compounding, not an action against GHK-Cu itself or against anyone else selling it.

Does GHK-Cu regrow hair?+

The study cited most often as evidence for GHK-Cu and hair is about a different molecule, AHK-Cu, a copper peptide with alanine in the first position instead of glycine. One letter of difference, and a generic title lets it pass for the other.

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This content is for educational and informational purposes only and is not medical advice. Peptides discussed are research compounds and may not be approved for human use. Nothing here should be used to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any peptide, supplement, or protocol. Individual responses vary. Do not self-administer compounds without proper medical supervision.