GHK-Cu

GHK-Cu is a peptide three amino acids long, glycine then histidine then lysine, holding a single copper(II) ion. The peptide part occurs in human plasma, and it entered the literature in 1973 in a paper reporting that a tripeptide isolated from human serum prolonged the survival of normal liver cells in culture. It has been sold since under two very different labels: as a cosmetic ingredient applied to skin, where its INCI name is copper tripeptide-1, and as a lyophilised powder in a vial intended for injection.

Those two products are the same molecule and two entirely separate evidence questions, which is why this site already carries a page setting the topical and injected routes apart. The literature is lopsided between them. Almost everything published is topical or in a dish. Injection into a body has been done in rodents, five studies of it, and never in a person for any purpose.

This page grades each claim area separately, names the model system on every result, and reports what the two randomized human trials measured and what they found. The reference list runs to 29 numbered sources: 22 primary research papers and reviews with every identifier checked against PubMed, three registry records read in full through the ClinicalTrials.gov API, and four FDA documents fetched from the agency. The regulatory section is current to 8 August 2026 and it has moved twice this year, which most writing about this compound has not caught up with.

Key takeaways

• GHK-Cu has been through two randomized human trials, in 1992 and 2006, and in neither of them did the copper peptide arm separate from its control on an objective measure. That is unusual in this category: most compounds sold alongside it have never been tested in a person at all. [Human RCT] [1] [2]
• One measure did separate in the 2006 trial, and it was the patients' own questionnaire on overall skin quality, at P equal to .04, in a study whose blinded and computer-assisted assessments found no difference. [Human RCT] [2]
• Neither trial is open access. Everything this page reports from them comes from the published abstract and the indexed record, and the human-record section says so in its own row.
• FDA's compounding position moved twice in 2026 and splits by route: the non-injectable form sits in 503A category 1 under evaluation, while the injectable form was in category 2 for significant safety risks before its nomination was withdrawn.
• FDA states it intends to consult the Pharmacy Compounding Advisory Committee about GHK-Cu before the end of February 2027. The committee's meeting of 23 and 24 July 2026 did not cover it: the seven substances voted on across those two days were BPC-157, KPV, TB-500, MOTS-c, emideltide, epitalon and semax.
• Two ex vivo studies of human skin disagree about whether topical GHK-Cu gets through it. A 2010 diffusion-cell study measured copper crossing dermatomed skin and forming a depot in it; a 2015 microneedle study reports that almost no peptide or copper crossed intact skin without pretreatment. [In-vitro] [3] [5]
• Whether the copper is the active half is not established. Copper-free GHK produced similar effects to the copper complex on keratinocyte stemness, and in two fibroblast studies copper chloride on its own moved the same markers in the same direction as the complex did. [In-vitro] [8] [9] [10]
• The only published animal work using the injected route is a rat knee study, and its difference against saline was gone by twelve weeks once the injections stopped. [Animal] [11]
• The figures repeated most often for this compound, on gene expression and on collagen, come from review articles rather than from trials, and those reviews share a first author who is also the person who described the tripeptide.
• The hair-growth study cited for GHK-Cu does not test it. It tests a two-component complex of 5-aminolevulinic acid and copper-free GHK, with no arm isolating the peptide, and it found no difference in hair length or thickness at six months. [Anecdote] [21]

Who researches GHK-Cu?

Readers arrive at this compound from three directions, and the published work speaks to them very unevenly.

The largest group is reading about skin: fine lines, firmness, texture, or recovery after a laser or needling procedure. That is where the human evidence sits, which makes this one of the few compounds in the catalogue where the question a reader arrives with has actually been asked.

The second group is reading about the injected form, usually framed as systemic repair or as an anti-ageing protocol. Nothing in the published record addresses that. There is one rat study using injections into a joint, a set of rodent studies giving the compound into the abdominal cavity for lung and muscle endpoints nobody markets it for, and no human study of any design on any injected route.

The third group arrives from the regulatory question, usually after seeing GHK-Cu described as FDA-cleared or as banned. Neither is right, and the actual record is more interesting than either: it splits by route, it changed twice in 2026, and there is a committee consultation on the calendar.

• Topical against injected: the same molecule, two evidence bases
• GHK-Cu against the palmitoyl peptide blends it is compared with

What is GHK-Cu?

Plain-English version: a chain of three amino acids, glycine then histidine then lysine, wrapped around a single copper ion.

The peptide on its own is glycyl-L-histidyl-L-lysine, written GHK: fourteen carbons, formula C14H24N6O4, 340.4 grams per mole. The histidine in the middle is what makes it interesting chemically, because that side chain binds copper(II) tightly, and the tripeptide plus the ion is what the market calls GHK-Cu or copper tripeptide-1 [20].

It arrived in the literature by accident rather than by design. A 1973 paper in Nature New Biology reported that a tripeptide isolated from human serum prolonged the survival of normal liver cells in culture and stimulated growth in neoplastic liver [28]. Everything sold under this name descends from that observation, which was about liver tissue in a dish and not about skin.

GHK is present in people. A 2023 respiratory study measured it in plasma by reversed-phase high-performance liquid chromatography and reported 133.0 plus or minus 54.54 nanograms per millilitre across eleven age-paired healthy adults, against 70.27 plus or minus 38.87 in the nine patients with chronic obstructive pulmonary disease it compared them with [14]. That endogenous presence is the observation almost all of the marketing rests on, usually in the form of a claim that the level falls with age.

One thing worth knowing before reading any figure attached to this compound: the complex does not have one settled molecular description. PubChem carries several separate records for GHK with copper at different charges and stoichiometries, from a singly charged anion at 400.9 grams per mole to a two-peptide species above 742. A molecular weight quoted for GHK-Cu therefore depends on which record it was taken from, and vendor documents rarely say. It is the same class of identity question FDA raised about the injectable form, and it is answered on a certificate of analysis or not at all.

Gly-His-Lys · C14H24N6O4, 340.4 g/mol for the free peptide

How strong is the evidence, claim by claim?

Every claim area this compound is discussed for gets a row, including the ones with the weakest support. The tier records what the row rests on, and the last column states what that work can and cannot show. Each tier links to its definition on the methodology page.

Rolled up, that puts GHK-Cu at evidence grade B Human data, endpoint missed . Human evidence for the marketed use has read out, and it did not separate from control: all 2 randomized trials that tested it missed the primary endpoint. The grade describes how much and how good the research is, not which way it came out, so a compound that has been tested and beaten grades above one nobody has tested at all. A grade describes the quality of the research, not whether something works and not whether anyone should use it. The derivation is published.

How GHK-Cu is thought to work

Mechanism work on GHK-Cu falls into two questions that get answered as though they were one. What the molecule does to cells has a long literature going back to the 1970s. What it binds to in order to do it has two candidate answers, both recent, both from the same research group, and neither confirmed elsewhere. A third question sits under both of them and is rarely asked out loud: whether the copper is the part doing the work.

What we do not know

The two ex vivo permeation results on human skin disagree with each other and nobody has reconciled them [3] [5]. That is the single most consequential gap on this page, because almost every product built on this molecule is applied to intact skin.

No pharmacokinetic measurement of administered GHK-Cu exists in a person on any route: no half-life, no clearance, no bioavailability figure. A 2025 review states plainly that the methods for measuring skin transport of liposome-encapsulated GHK-Cu are still being developed [6], and the injected route has no measurement of any kind.

The copper question above is open in both directions. Nothing published establishes that the complex outperforms the free peptide, and nothing establishes that it does not.

The two proposed molecular targets come from one research group, and the four rodent disease studies behind them come from that same group [12] [13] [14] [15]. Concentration of authorship is a quality signal this site reports on every compound, and it is not an accusation: a group that builds an assay keeps using it, and small fields are small.

Whether the endogenous plasma level has anything to do with what a product does is unmeasured. Two of those studies report lower plasma GHK in patients with a lung condition [14] [15]. An association between a measured level and a disease is not evidence that adding more of it changes the disease, and no trial has tested that step.

Has GHK-Cu been tested in humans?

Two randomized controlled trials of GHK-Cu in people have been published, thirty-four and twenty years ago. Both are topical. Both are in the table below with what they measured and what they found.

The table also carries the three registry records that a search for this compound returns, because only one of them is a trial of the compound itself, and the last row records a limit on this page's own sourcing that a reader is entitled to know about.

Why we are not calling this proof

Two randomized trials against a control is more human testing than most compounds in this catalog have ever had, and it is worth being exact about what that buys and what it does not.

It buys a real answer to a narrow question, twice. A copper tripeptide cream at one concentration did not shrink venous stasis ulcers faster than an inert vehicle, in a trial where a third arm did. A GHK-Cu skin regimen did not clear post-laser redness faster than the same regimen without it, and did not change wrinkles or skin quality on any assessment an evaluator made. Neither of those is a verdict on the molecule. They are results for one formulation, one concentration and one clinical situation each.

It does not buy an answer about anything else this compound is sold for. Nothing in the human record touches the injected route, the anti-ageing framing, hair, or systemic repair. The 2006 trial ran to thirteen patients, which is small enough that it could miss a real difference as easily as it could report a false one.

One word in the grade explanation above needs its own line, because the two trials do not use the term the same way. The 2006 report names its objective outcomes and its questionnaire separately, so calling the objective ones its primary endpoints is fair. The 1992 report predates that convention and simply reports ulcer size. The grade explanation says both trials missed their primary endpoint, and what that means precisely, for both of them, is that the arm receiving the copper peptide did not differ from its control on the outcome the trial reported.

The FTC sets the substantiation bar for a health claim at randomized controlled human trials and says animal work, laboratory work and observational data are generally not enough on their own. GHK-Cu has two of the first, and both came back the same way on their objective measures. That is the whole human picture, and the recruiting phase 2 is the first registered study capable of changing it.

That trial deserves the same reading this page gives the older literature, because a registration is a document like any other and this one has features worth knowing. It is sponsored by Hudson Biotech, runs at a single site, Peking University Shenzhen Hospital, and lists both of its contacts at an email domain that does not match the sponsor's name. Its oversight block records it as not FDA-regulated. It was first submitted on 22 February 2026 and first posted five days later, which is after the start date it reports, and nothing in the record has been updated since. Two of its intervention and arm strings are cut off mid-word. None of that says the trial is not running or that its result will not count. It does say that the strongest thing on this page's horizon rests on one unamended registration at one site, and a reader weighing it is entitled to that before February 2027 rather than after.

Benefits: what the research shows

Each heading below is a claim people make about GHK-Cu, not a finding. Under each one is what was measured, in what, and by whom.

Four review articles cover most of this ground and are worth naming, because they are frequently cited as though they contained data of their own [17] [18] [19] [20]. They summarise cell and animal work. None of them adds a human result.

The honest bottom line on benefits

What the two trials leave is a narrow answer rather than a verdict, and the narrowness runs both ways. Most writing about this compound avoids the result entirely; a smaller amount treats it as proof the molecule is inert. Neither reading survives contact with what was actually tested, which was one cream in one chronic wound and one regimen after one procedure.

There is a second thing to say, and it cuts the other way from how counts usually get used. The preclinical file is not as independent as its length suggests. Four of the rodent studies and both proposed molecular targets come from one research group [12] [13] [14] [15]. Two of the three fibroblast studies come from a second [8] [9]. The four reviews that carry the most-repeated figures share a first author [17] [18] [19] [20]. A reader weighing a long reference list should know that it represents fewer independent lines of work than the number of entries implies.

Set against that, the thing this compound has that its shelf-mates do not is a live, registered, vehicle-controlled trial of the topical form with a real primary outcome and a date on it [22]. Between February 2027 and whatever FDA does after its advisory committee consultation, the record on this page is likely to look different within about eighteen months.

What anyone does with that is a judgement rather than a fact, and it belongs to the reader. This site reports what has been documented. It does not prescribe what should be done.

How long GHK-Cu stays in the body

Two different quantities get discussed under this heading and only one of them has ever been measured. The first is the level a person already carries, which is the plasma figure in the opening section [14]. It is a baseline, and it says nothing about what a product delivers.

The second is what an administered amount does once it is in, and that has no published measurement in any species: no half-life, no clearance figure, no bioavailability figure. Any such number in circulation therefore came from somewhere other than a measurement of this compound, and the most likely source is arithmetic on the first quantity.

For the topical route, the closest thing to a measurement is the pair of contradictory ex vivo permeation studies above [3] [5], and a 2025 review whose conclusion is that the analytical methods for answering this question are still being developed [6]. For the injected route there is nothing at all: the one animal study using injections into a joint measured outcomes rather than exposure [11].

No half-life, clearance or bioavailability figure has been reported for administered GHK-Cu in any species. What exists instead is a measurement of the level people already carry in plasma, and two ex vivo skin-permeation results that disagree with each other. [In-vitro] [3] [5] [6] [14]

What is documented about dosing

No study has established an amount of GHK-Cu for a person, so there is no dosing section on this site in the sense other properties use the phrase. What can be reported is what published studies used, in the model they used, and what kind of figures circulate elsewhere.

Commonly cited protocols (extrapolated, not validated)

Nothing here is a dosing recommendation. Statements about dosing reflect community and research reports only.

Two things in that table are worth pulling out. The first is that the human trials tested products rather than substances: a cream and a skin care regimen, each with a formulation that shapes what reaches skin as much as the peptide concentration does.

The second is that the culture work has a shape that a single number destroys. The 1992 glycosaminoglycan response peaked between one and ten nanomolar and returned towards control above it [7], so a higher concentration is not a stronger version of the same result, and no published work establishes what concentration living skin reaches under any product.

Main routes people compare, and what each source class actually reported, are set out on the documented protocols page.

Reported effects and what has been measured

What the two human trials report

Both randomized trials were conducted in patients and both completed, at 86 evaluable and 13 completed respectively [1] [2]. Neither abstract reports a safety or tolerability endpoint, and neither paper is open access, so this page cannot say what either study recorded on that question.

That is a gap in what can be read rather than a finding in either direction. An abstract omitting safety is not a study reporting none, and this site does not convert one into the other. [Human RCT] [1] [2]

What FDA has said about the injected form

The one agency statement that addresses harm rather than paperwork is FDA's rationale for putting the injectable form in category 2. In the agency's own words: compounded injectable drugs containing GHK-Cu may pose risk for immunogenicity due to the potential for aggregation and peptide-related impurities, and there are limited data in humans to inform safety-related considerations. The regulatory table below carries the same finding with its document and date.

Two precisions matter and both are routinely lost. That statement is about injectable routes and nothing else, so it says nothing about a cream. And a risk the agency calls potential is one it has not ruled out, not a harm it has documented. Those are the two opposite ways this sentence gets misread.

Aggregation is worth a plain-language line, because it is the mechanism behind the concern. Peptide molecules can clump together into larger particles, and an immune system is more likely to react to a clump than to a single small molecule. FDA raises it here as an unassessed possibility rather than as something measured in this compound.

What the toxicology record contains

What the record holds on toxicology is a pair of remarks made inside efficacy studies. The 2024 silicosis paper states that GHK-Cu attenuated lung inflammation and fibrosis in mice without significant systemic toxicity [12]. The rat knee study's abstract does not mention adverse findings either way, in an experiment designed to measure ligament healing rather than harm [11].

An observation made in passing in a study built to measure something else is not a toxicology result. A compound with a clean fourteen-day rodent toxicology study has a measurement behind it. This one has remarks.

The formal package that would carry those measurements was not located for this page under this compound's name: no acute study, no repeat-dose study, no genotoxicity study, no reproductive study and no carcinogenicity study appears in the published literature. [Animal] [11] [12]

The copper question, which is specific to this molecule

This compound carries a metal, which makes exposure a different question from the one that applies to a plain peptide. Copper is an essential trace element at low intake and toxic at high intake, and the amount a body handles depends on how much arrives and how often.

Nobody has measured that for this compound in a person on any route. The two ex vivo permeation studies measured copper crossing removed human skin and disagreed with each other by a wide margin [3] [5], which means the input side of the question is unsettled before the exposure side can be asked. No published study has measured serum or tissue copper in a person using a topical or injected GHK-Cu product.

This is not a statement that harm has been observed. It is a statement that the measurement that would answer the question has not been made. [In-vitro] [3] [5]

What has not been characterised

The identity question raised in the opening section belongs here too. The complex has no single settled molecular description in the public chemistry databases, which carry several records at different charges and stoichiometries. A substance whose composition is described more than one way cannot have its impurity profile described precisely either, and FDA named aggregation and peptide-related impurities as its concern for the injected form.

No published stability or shelf-life study of GHK-Cu was located, in any presentation. No degradation product has been characterised. And no published work describes what happens to the compound in a product over time or under handling, which is a question every certificate of analysis is silent about.

Long-term exposure has been characterised in no species. The published studies ran days to weeks, and the longest human assessment on record is twelve weeks.

Talk to a licensed clinician about anything concerning your health.

Sourcing and quality

What a credible product should show

A certificate of analysis is the document that matters, and for this compound it has to answer one question that does not arise for a plain peptide: which copper species is in the vial or the jar, and in what ratio to the peptide. The public chemistry records carry several forms at different charges and stoichiometries, so a certificate naming only GHK-Cu has not identified the material.

Three things make any certificate checkable: a lot number that matches the container in front of you, a test date, and the name of the laboratory that ran the test rather than the name of the company selling the material.

What the common tests establish is narrower than it looks. High performance liquid chromatography separates what is in a sample and reports relative peak area, which is a statement about chromatographic purity rather than about identity. Mass spectrometry addresses identity by measuring molecular weight, and for the free peptide that should land at 340.4. Neither test says how much is in the container: that is net peptide content, reported separately if at all. And neither says how much copper is present, which for this compound requires its own elemental measurement.

Red flags

A certificate with no lot number cannot be tied to the container in your hand, whatever else it says. A certificate reproduced from a supplier without an independent test is a supplier's claim rather than a verification. A certificate dated well before the material was made covers a different batch.

A purity figure with no method named is not a purity figure. Ninety-nine percent by which measurement, against which reference standard, with how much material in the container, and with how much copper are five separate questions, and one percentage answers none of them.

A molecular weight quoted for the complex without saying which species it refers to is a specific problem here rather than a general one, because there is more than one right answer and the databases carry several.

Widely circulated statistics about what fraction of products in this market are underdosed, or what fraction of certificates are fabricated, trace back to affiliate content sites rather than to a published testing program. This site does not publish them, because nobody has traced them to primary data.

This site names no company adversely and names none favourably either. There is no best-vendor list here, no rating and no top pick, and there will not be one.

Will it show on a drug test?

The question people ask is whether a copper peptide product could produce a positive test, and the honest answer starts with a fact that makes the question harder than it looks: GHK is already in everyone's blood. A 2023 study measured it in plasma at 133.0 plus or minus 54.54 nanograms per millilitre across eleven healthy adults [14].

So a test looking for the peptide itself would have to distinguish an administered amount from the amount a person already carries, and no published work establishes what a topical or injected product adds to that baseline. No pharmacokinetic study of administered GHK-Cu in a person exists on any route, which means nothing published supports or refutes a detection claim in either direction.

Anti-doping status is decided by an athlete's own anti-doping organization against the current Prohibited List, and this site publishes no reading of that list for this compound because it has not verified one against the primary document. The KPV review sets out how the S0 Non-Approved Substances category reaches a compound that is not named on the list, which is the mechanism most likely to be relevant here, and an athlete's own organization is the only body whose answer counts.

Workplace testing and anti-doping testing are different systems with different panels, and neither publishes a position on this compound.

Storage

Storage is a two-part question for this compound and only for compounds like it, because the molecule is a peptide holding a metal ion by a coordination bond rather than a covalent one. The peptide can degrade and the complex can come apart, and a measurement of one is not a measurement of the other.

Published work addresses neither for a marketed product. No stability study of GHK-Cu was located in any presentation, and no shelf life has been published for it. That is the whole of the record on this question.

This site publishes no handling or preparation procedure. That is a standing rule and the reasoning is on the editorial policy page.

Regulatory status, as of 8 August 2026

The regulatory position on GHK-Cu is the part of its file that changed most recently, and it splits by route in a way almost nothing written about this compound reflects.

Start with what category 1 means, because it is the single most misreadable fact here. Under FDA's interim policy on compounding with bulk drug substances, category 1 covers substances that were nominated for the 503A Bulks List with enough supporting information for the agency to evaluate them, that do not appear on any other list, and that the agency is still evaluating. FDA states that it does not intend to take action against a compounder using a category 1 substance provided the conditions in the guidance are met. That is a stated enforcement posture during an evaluation. It is not approval, it is not endorsement, and it is not a finding that anything has been established about the substance [24].

The 2026 sequence is worth stating in order, because a single sentence about it will be wrong. GHK-Cu for routes other than injection was in category 1. On 22 April 2026 it came off, because the nominations for GHK-Cu were withdrawn by the nominators. On 5 May 2026 one of those nominators clarified that it had meant to withdraw only its nomination of the injectable route and wished to keep its nomination for non-injectable routes, and FDA records that the substance will be added back to category 1 [24].

The injectable side went the other way and is a separate record. That route had been placed in category 2, which FDA uses for nominated substances where it has identified significant safety risks pending further evaluation, and its nomination was withdrawn as well. The agency's stated rationale is quoted in the second row of the table above and is discussed in the safety section [25]. What matters structurally is that the two routes now sit in different places in the same policy, so a sentence about GHK-Cu and FDA is wrong unless it says which route it means.

The next event is already on the record. FDA states it intends to consult the Pharmacy Compounding Advisory Committee about the potential inclusion of GHK-Cu on the 503A Bulks List before the end of February 2027 [24]. This page publishes no prediction about what the agency will decide, and no meeting date has been posted. What can be said is that the committee's meeting of 23 and 24 July 2026, which several write-ups have attached to this compound, did not cover it: the questions document for that meeting runs to seven substances across four sessions and GHK-Cu is not one of them. A case-insensitive search of the document for the letters GHK returns nothing [26].

The cosmetic side is a different statute and gets confused with all of the above. A topical product carrying copper tripeptide-1 is lawfully sold without any agency having evaluated it, because FDA does not run a premarket approval step for cosmetic ingredients [27]. That absence is not evidence about the ingredient in either direction, and reading it as clearance is the mirror of reading category 1 that way.

The line between the two statutes is drawn by intended use rather than by contents, and that is the part with practical consequences. Under section 201(g) a product intended for a therapeutic use, or to affect the structure or function of the body, is a drug even where it also affects appearance [27]. So a jar of cream can move across that line on the strength of what its seller writes about it, with nothing inside the jar changing. It is the same reasoning FDA applied to research-use-only labelling, and it is why the editorial standard this site publishes under is stricter than an independent publisher's.

GHK-Cu compared with other peptides sold for repair and skin

Two of these four compounds carry a grade and two do not, and that is deliberate: a grade on this site is derived from tiered claim rows, and the source review behind those rows has not been run on BPC-157 or TB-500.

The comparison worth understanding is the one between GHK-Cu and KPV, because it shows what the grade scale does and does not measure. KPV sits at D because nobody has ever tested it in a person. GHK-Cu sits at B because it has been tested twice, and neither test separated it from its control. The letter records how much research exists and how good it is, not which way the research came out, which is why the sentence beside the badge on this page carries the direction in words.

The route split within this compound is a bigger practical difference than any of the comparisons above, and it has its own page.

What GHK-Cu typically costs

GHK-Cu is sold in two completely different formats: as an ingredient inside finished topical products, where the peptide is a fraction of what is being bought, and as a lyophilised powder in vials. What any of it costs is not published here, and the price comparison page sets out why, along with the four things that actually move a listing.

The one thing worth carrying away is that nothing in a price says anything about identity, content or testing, and for this compound that includes which copper species is present. Those are certificate questions, and they are covered in the sourcing section above.

See the price comparison.

Frequently asked questions

References

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2. Miller TR, Wagner JD, Baack BR, Eisbach KJ. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. 2006. PMID 16847171 DOI 10.1001/archfaci.8.4.252
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14. Deng M, Zhang Q, Yan L, Bian Y, Li R, Gao J, Wang Y, Miao J, Li J, Zhou X, Hou G. Glycyl-l-histidyl-l-lysine-Cu(2+) rescues cigarette smoking-induced skeletal muscle dysfunction via a sirtuin 1-dependent pathway. J Cachexia Sarcopenia Muscle. 2023. PMID 36905132 DOI 10.1002/jcsm.13213
15. Zhang Q, Liu J, Deng MM, Tong R, Hou G. Relief of ovalbumin-induced airway remodeling by the glycyl-l-histidyl-l-lysine-Cu(2+) tripeptide complex via activation of SIRT1 in airway epithelial cells. Biomed Pharmacother. 2023. PMID 37257226 DOI 10.1016/j.biopha.2023.114936
16. Wen H, Zhao K, Luo X, Pu J, Li Y, Dou Y, He J, Nie X, Ke Y, Zhou W. The GHK-Cu delays aging in Caenorhabditis elegans via coordinated regulation of mitochondrial function and activation of DAF-16/SKN-1 pathways. Biogerontology. 2026. PMID 42084774 DOI 10.1007/s10522-026-10444-x
17. Pickart L, Vasquez-Soltero JM, Margolina A. GHK and DNA: resetting the human genome to health. Biomed Res Int. 2014. PMID 25302294 DOI 10.1155/2014/151479
18. Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. Biomed Res Int. 2015. PMID 26236730 DOI 10.1155/2015/648108
19. Pickart L, Vasquez-Soltero JM, Margolina A. The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health. Oxid Med Cell Longev. 2012. PMID 22666519 DOI 10.1155/2012/324832
20. Pickart L. The human tri-peptide GHK and tissue remodeling. J Biomater Sci Polym Ed. 2008. PMID 18644225 DOI 10.1163/156856208784909435
21. Lee WJ, Sim HB, Jang YH, Lee SJ, Kim do W, Yim SH. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth. Ann Dermatol. 2016. PMID 27489425 DOI 10.5021/ad.2016.28.4.438
22. Hudson Biotech. A Phase 2, Randomized, Double-Blind, Vehicle-Controlled, Split-Wound Study of Topical GHK-Cu (Copper(II)-Peptide Complex) Gel to Accelerate Re-Epithelialization of Standardized Acute Skin Wounds in Healthy Adults. Registry record read in full through the ClinicalTrials.gov API v2 on 8 August 2026: recruiting, actual start 2 February 2026, estimated primary completion 14 February 2027, no results posted. ClinicalTrials.gov, NCT07437586. 2026. Source document
23. Austin Institute for Clinical Research. A Phase IV Open-label Trial Assessing the Impact on Skin Quality, Hydration, and Barrier of Three (3) Hydrafacial Treatments in Adults of Fitzpatrick Skin Types I-VI. Registry record read in full through the ClinicalTrials.gov API v2 on 8 August 2026: completed 9 October 2024, 27 participants, no results posted. Three interventions, of which one is a drug: a booster serum whose registered description lists the compound among its ingredients, applied to every participant. ClinicalTrials.gov, NCT05932732. 2024. Source document
24. US Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act. Document updated 14 May 2026, carrying the category 1 list and the GHK-Cu withdrawal and clarification history. FDA human drug compounding. 2026. Source document
25. US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Category 2 of the bulk substances nominated under sections 503A or 503B, with the table of substances previously in category 2 whose nominations were withdrawn. Page content current 22 April 2026. FDA human drug compounding. 2026. Source document
26. US Food and Drug Administration. Questions for PCAC regarding whether FDA should include certain bulk drug substances on the 503A Bulks List, Pharmacy Compounding Advisory Committee, 23 and 24 July 2026. Seven substances are put to a vote across four sessions, two questions each: BPC-157, KPV, TB-500, MOTS-c, emideltide, epitalon and semax. Read in full on 8 August 2026; a case-insensitive search for GHK returns nothing. FDA advisory committee materials. 2026. Source document
27. US Food and Drug Administration. FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. Page content current 18 November 2025. FDA cosmetics laws and regulations. 2025. Source document
28. Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973. PMID 4349963
29. LifeWave, Inc. A Two-part Study Investigating the Effect of the X39 Patch on Circulating Blood Levels of GHK and GHK-Cu in a Healthy Adult Population. Registry record read in full through the ClinicalTrials.gov API v2 on 8 August 2026: not yet recruiting, estimated start January 2027, 100 participants estimated. Its four primary outcomes are changes in circulating GHK and GHK-Cu levels from baseline to day 8, so the compound is the quantity measured rather than the intervention. ClinicalTrials.gov, NCT07706361. 2026. Source document