Where to Buy GHK-Cu: 7 Purity and Identity Checks, and the 62.5 Daltons That Decide Whether the Copper Is There

GHK-Cu is sold as a copper complex, and the certificate that comes with it cannot detect copper. HPLC measures peak area, not metal. The one test that settles it reads either 340 or 403, and most vendors do not run it.

That makes GHK-Cu the odd compound in the skin and anti-aging peptides category: the usual buying advice, look for a high purity number, is compatible here with receiving exactly the wrong molecule at high purity. Identity and price sit on the GHK-Cu compound page, and the evidence picture is in GHK-Cu: the copper peptide whose purity certificate cannot detect copper. This page is about the vial, the label and the certificate.

What is GHK-Cu, and why does source quality matter?

GHK-Cu is a 1:1 copper complex of the tripeptide glycyl-L-histidyl-L-lysine, weighing about 403 daltons, sold for skin and anti-aging use. Source quality matters because the copper-free peptide weighs 340.38 daltons, costs less to make, and passes an HPLC purity test perfectly. PubChem indexes that copper-free molecule, CID 73587, under the synonyms GHK-Cu, Copper Peptide and Prezatide, so the naming confusion starts in the reference databases themselves.

There are three chemical records here, not two, and a buyer who knows only two of them cannot read a spec sheet correctly.

Copper-to-peptide stoichiometry is 1:1 across all copper records. The full synonym list on the copper-free record runs "GHK-Cu," "Copper Peptide," "Copper(II)ghk," "Copper glycyl-histidyl-lysine," "Prezatide" and "Tripeptide-1" — six names for a copper complex, attached to a molecule containing no copper. A vendor building a listing from database synonyms rather than from a certificate will reproduce that error without ever intending to mislabel anything.

One sourcing warning before you check anything against a reference. Wikipedia's chembox for the copper complex gives C₁₄H₂₂CuN₆O₄ with CAS 89030-95-5, a formula matching none of the three PubChem records, since PubChem's record for that CAS is the monocation C₁₄H₂₃CuN₆O₄⁺. Wikipedia also lists a different CID for free GHK than PubChem's own. Do not source GHK-Cu identity data from there, and do not accept a vendor spec sheet that reproduces those figures.

Our own compound page flags the commercial consequence independently: it notes that "some vendors sell free GHK labeled as GHK-Cu (mislabeling) or use suboptimal copper-to-peptide ratios." The PubChem synonym evidence is the documentary backing for that flag, and how it shows up on paper is covered in red flags in peptide certificates of analysis.

What is the regulatory status of GHK-Cu?

GHK-Cu is not approved for human use and, as of August 2026, has no compounding route. It is absent from FDA's active Category 2 list; on the page current 22 April 2026 it appears in the second table, Bulk drug substances nominated but withdrawn, specified as GHK-Cu for injectable routes of administration. Neither GHK, GHK-Cu, copper peptide nor copper appears anywhere on the 2026 WADA Prohibited List.

Because the nomination was withdrawn and GHK-Cu never reached the 503A bulks list, no statutory compounding route exists, so this page has no compounded-GHK-Cu section. There is no approved product to copy and no 503A or 503B pathway to compare against research-grade supply. The only question a buyer can act on is what is in the vial.

Withdrawal by the nominator is procedural rather than a safety clearance, and FDA's stated concerns remain published:

"Compounded injectable drugs containing GHK-Cu may pose risk for immunogenicity due to the potential for aggregation and peptide-related impurities. There are limited data in humans to inform safety-related considerations."

The route specification is the detail most summaries drop. FDA did not write about copper peptides in cosmetics. It wrote about injectable routes of administration, which is precisely the use with no human evidence behind it. Where each nomination actually stands is tracked in our FDA peptide regulation timeline.

On sport, the absence from the 2026 Prohibited List is genuine, but the S0 catch-all covers pharmacological substances without approval for human therapeutic use, and the status is ambiguous: a topical cosmetic is not obviously a pharmacological substance for therapeutic use, while an injected preparation is a much stronger S0 candidate. We are not asserting either way.

Two of those verdicts are different in kind from the others. "Wrong molecule" and "False" are factual corrections, not judgements about strength of evidence, and they hold regardless of how the efficacy question eventually resolves.

How do you tell copper-bound GHK-Cu from copper-free GHK?

Mass spectrometry tells you and HPLC cannot. The two candidates differ by roughly 62.5 daltons, about 18% of the molecule: 340.38 for the free tripeptide against about 403 for the 1:1 copper complex. That gap is trivially visible on a mass spectrum and completely invisible to HPLC, which separates by hydrophobicity and reports peak area. Elemental analysis measures copper directly, and we have not seen it offered by any vendor or laboratory serving this market.

An 18% mass difference is enormous by peptide-identity standards. Buyers in this cluster are usually asked to worry about pairs separated by 1 Da or 16 Da; here the two candidate molecules are separated by more than a sixth of the total mass, and the test that would resolve it is routine. The reason nobody runs it is that nobody asks.

The asymmetry inverts the usual advice, so it is worth stating flatly. For most peptides a high HPLC figure is genuinely reassuring. For GHK-Cu, a sample of pure copper-free GHK returns a beautiful purity number. What mass spectrometry for peptides settles in a single reading, a purity certificate cannot settle at all, and the reasons are structural rather than a matter of laboratory diligence, as what HPLC testing measures sets out. Assays that do look for metals are a separate discipline entirely, covered in peptide heavy metals testing.

7 things to check before ordering GHK-Cu

Seven checks cover GHK-Cu, and the first one decides everything else: a mass spectrometry result near 403 daltons rather than 340.38. After that come the CAS number on the label, the stated copper-to-peptide stoichiometry, third-party HPLC purity read live against the Purity Index, net peptide content and endotoxin on the same batch, a pricing sanity check against a median of $0.70 per milligram, and what no certificate can establish.

1. A batch-matched mass spectrum reading near 403 Da. This is the check. Roughly 403 is the copper complex; 340.38 is the copper-free peptide wearing its name. Insist on a result tied to your lot rather than a specimen certificate from an earlier batch, because the substitution risk is per-batch, not per-vendor. A CoA carrying a purity percentage and no mass result has not addressed the only question that matters on this compound.

2. Copper content and 1:1 stoichiometry, if anyone will run it. Elemental analysis measures the metal directly, and stoichiometry is 1:1 across every copper record. Our compound page flags "suboptimal copper-to-peptide ratios" as a real market practice, which mass spectrometry alone will not fully characterise. Expect to be told no: we have not seen this assay offered by any vendor or laboratory serving this market, and asking establishes whether the seller understands the question.

3. Third-party HPLC purity from a named laboratory, read live. GHK-Cu's platform baseline is 99.66% across 736 independent HPLC tests, with individual results between 99.31% and 99.94%, so a vendor's "above 98%" house standard is below the observed floor of the category. Read the current figure on the Purity Index rather than a number quoted in prose, and require the lab to be named — an unattributed certificate is a claim, not a measurement, as third-party peptide testing labs sets out.

4. The label and the spec sheet, read against the three records. 49557-75-7 is free GHK; 89030-95-5 is prezatide copper. A vial printing 340.38 under a GHK-Cu heading has described the wrong molecule on its own packaging. Treat any of the six copper-free synonyms, including "Tripeptide-1" and "Copper(II)ghk", as ambiguous rather than confirmatory, and reject a spec sheet reproducing the Wikipedia formula C₁₄H₂₂CuN₆O₄.

5. Net peptide content and an LAL endotoxin result on the same batch. Purity and quantity are separate axes, and a 99% pure vial can be substantially underfilled, which is what net peptide content measures. Endotoxin is a third axis, and it matters more here than on most compounds because FDA's published concern is specifically aggregation and peptide-related impurities in injectable GHK-Cu. An absent LAL result means the batch was not tested, as peptide endotoxin testing explains.

6. Shop-level reviews before product-level documents. Trust scores weight community reviews and independently verified HPLC purity equally, at 50% each, with no financial relationship influencing the ranking. A vendor with clean certificates and a poor delivery and substitution record is still a poor vendor. Read community-verified shop reviews alongside the certificates, and screen for the patterns in how to spot a scam peptide shop.

7. A price sanity check, and what no certificate can establish. The median is $0.70/mg and the lowest $0.12/mg on a 100 mg vial, so a listing far under the floor on a small vial is worth a second look, since the copper-free peptide is the cheaper thing to ship. And a perfect certificate still cannot tell you the compound works: no published human study of injected GHK-Cu exists by any route, and the one indexed RCT found no objective improvement.

Note what checks 1 and 2 have in common. On most compounds the identity problem is expensive to solve; here the decisive test is routine, the mass gap is 18%, and the reason it goes unrun is commercial rather than technical.

Where does GHK-Cu rank on Peptigrity's lab test database?

GHK-Cu holds the deepest dataset on this platform: 99.66% average purity across 736 independent HPLC tests across 230 verified vendors (verified May 2026), with individual results running 99.31% to 99.94% and the most recent test in August 2026. None of those 736 tests measures copper. The price page shows 59 shops in stock, median $0.70/mg and lowest $0.12/mg on a 100 mg vial (verified 8 August 2026).

That is the central problem of this compound restated in platform terms. The largest body of first-party evidence we hold cannot answer the question buyers most need answered, and saying so is more useful than quoting the 99.66% as though it settled something. Individual certificates are searchable in the lab test database, and the live figure sits on the Purity Index. Peptigrity tracks 530 shops and 11,852 independent lab tests across 118 peptides, with 1,283 community reviews (verified August 2026).

On cost, GHK-Cu price data publishes shops in stock, median and lowest price per milligram with the vial size behind the lowest figure. Compare within a single vial-size band: the $0.12/mg floor is a 100 mg vial, and fixed per-vial costs push the per-milligram figure down as fill size rises, which makes a large vial look like a better product rather than simply a bigger one. Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing.

There is a pricing consideration specific to this molecule, and it is not really about money. GHK-Cu is 15.7–15.8% elemental copper by mass, our calculation from the verified molecular weights and copper's atomic weight of 63.546, so a price per milligram of peptide is also a dose of metal.

A 100 mg vial at the floor price is cheap peptide and, if the copper is genuinely there, several thousand micrograms of parenteral metal. No human pharmacokinetic data exists for this compound, so nothing describes how a copper load of that size is handled. Protocol questions are handled separately in the GHK-Cu dosage protocol guide, which describes what people do rather than what has been demonstrated.

The trial that would settle this is two trials, and only one of them is under way.

NCT07437586, a Phase 2 randomised, double-blind, vehicle-controlled split-wound study of a 0.1% gel started in February 2026, may deliver on the first row. Nothing addresses the rest. Note the fifth row especially: a trial cannot characterise a compound it has not confirmed the identity of, which is the same check a buyer is being asked to make with far less equipment.

Frequently Asked Questions

What purity standard should GHK-Cu meet?

The platform baseline is 99.66% average across 736 independent HPLC tests, with individual results from 99.31% to 99.94%, so a vendor advertising "above 98%" is quoting a standard below the observed floor for this compound. Read the current figure live rather than trusting a number in prose. On GHK-Cu, though, purity is the second question, because an excellent HPLC result is exactly what pure copper-free GHK produces.

How much does GHK-Cu cost?

Fifty-nine shops were in stock at a median of $0.70 per milligram, with the lowest at $0.12 per milligram on a 100 mg vial (verified 8 August 2026). Compare within one vial-size band, because fixed per-vial costs fall away as fill size rises and make larger vials look cheaper per milligram than the product warrants. Those figures exclude shipping, taxes, coupon codes and bulk tiers.

Is GHK-Cu legal to buy?

It is not approved for human use, and as of August 2026 there is no compounding route. FDA lists "GHK-Cu (for injectable routes of administration)" in its "nominated but withdrawn" table rather than on the active Category 2 list, and the withdrawal was the nominator's decision rather than a safety clearance. Nothing named GHK, GHK-Cu, copper peptide or copper appears on the 2026 WADA Prohibited List.

How do I confirm the copper is actually there?

Ask for a batch-matched mass spectrum and look at the number: roughly 403 daltons is the copper complex, 340.38 is the copper-free tripeptide. That 62.5 Da gap is about 18% of the molecule and unmistakable on a trace. Elemental analysis would measure the metal directly at 1:1 stoichiometry, but we have not seen it offered by any vendor or laboratory serving this market.

Is injectable GHK-Cu supported by any human evidence?

No. There is no published human study of injected GHK-Cu by any route. All three ClinicalTrials.gov records are topical or patch-based, and the PubMed injection literature is entirely animal and in vitro. The subcutaneous protocols circulating in forums have no clinical basis at all, which is different from having a weak or extrapolated one.

How much elemental copper does an injection deliver, and who should avoid it?

GHK-Cu is about 15.8% elemental copper by mass, so a 10 mg dose carries roughly 1,577 µg, about 175% of the 900 µg adult RDA, and a 20 mg dose about 3,154 µg. That sits below the 10 mg/day oral upper limit, but the oral limit assumes regulated intestinal absorption, which injection bypasses; copper leaves the body primarily through bile. People with Wilson's disease, an autosomal recessive defect in copper clearance, are at particular risk and frequently do not know they carry it.

Browse the skin and anti-aging peptides category, or our complete peptide guide with 118 compounds (verified August 2026). For reconstitution and per-injection volume, use the GHK-Cu calculator alongside the reconstitution calculator. Compare shops through independent lab tests and community-verified shop reviews.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.