GHK-Cu
A copper-binding tripeptide found naturally in human plasma. Most research concerns cells, laboratory skin, animals or topical cosmetic use, not the injectable prescription route.
Last reviewed September 22, 2026
The short version
GHK-Cu is a naturally occurring three-amino-acid peptide carrying a copper ion. Copper Tripeptide-1 in a topical cosmetic and GHK-Cu prepared as an injectable prescription are not the same regulatory or evidence question. Human research is small and mostly topical; much of the broader biology comes from cells, laboratory skin and animal work.
There is no FDA-approved injectable GHK-Cu drug. Its compounding nomination for injectable routes was withdrawn, while FDA’s published safety note remains. A licensed provider’s clinical decision does not change those FDA facts.
What it is
GHK-Cu is the copper(II) complex of glycyl-L-histidyl-L-lysine. The free peptide, GHK, occurs in human plasma, saliva and urine; GHK-Cu forms when that three-amino-acid chain binds copper. In cosmetic ingredient lists it is called Copper Tripeptide-1. Cosmetic use on skin must be kept separate from systemic or injectable use, because route changes both the evidence and the FDA framework.
GHK-Cu has the sequence Gly-His-Lys, molecular formula C14H23CuN6O4+, molecular weight 402.92 daltons and CAS number 89030-95-5. The free GHK peptide is a related but distinct substance without the bound copper ion.
Where the research stands
The literature describes measurements in cell and laboratory tissue systems. Human studies are limited, small and usually topical. The studies cited here do not establish the safety or effectiveness of injecting GHK-Cu.
How far the evidence has climbed
- Cell studiesYesFibroblasts, gene data and hair-follicle cells
- Animal studiesYesSeveral tissue-remodeling models
- Small human pilotsLimitedMainly topical and combination products
- Controlled human trialsLackingNo controlled injectable trial
- FDA approvalNoNo approved injectable GHK-Cu drug
Here is what some of the most-cited studies looked at. Each names its species, because a result in a cell dish is not a result in a person.
Collagen in fibroblast cultures
This study measured collagen synthesis and cell number in cultured human fibroblasts. It did not test an injectable treatment or a patient outcome.1
Tissue-remodeling literature
A review summarized human, animal and cell models involving matrix proteins, growth signals and inflammatory pathways. The varied models and routes do not establish an injectable patient outcome.2
Movement through laboratory skin
An ex vivo study measured copper movement and retention when GHK-Cu was applied to removed human skin. It did not test an injectable route or a patient outcome.3
Topical and cell evidence
A review summarized small topical studies, in vitro findings and age-related associations in circulating GHK. It did not test injected GHK-Cu as a treatment.4
A combination hair product
A six-month study enrolled 45 men and measured outcomes for a topical product combining GHK with another ingredient. It did not isolate GHK-Cu or test injection.5
The topical delivery problem
A review found that movement through the outer skin barrier remains a central challenge and evaluated experimental delivery methods. It did not provide evidence for injection.6
What the research can’t tell you
Topical is not injectable
Skincare studies cannot establish the pharmacology or safety of putting GHK-Cu into the body. The cited research does not establish how injected GHK-Cu is processed in people.
Small, mixed human evidence
The human studies are small, and some test combination products. They cannot isolate the peptide or establish a broad clinical outcome.5
Form matters
Free GHK and copper-bound GHK-Cu are often blurred together. Findings for one form or delivery system do not automatically transfer to the other.
Systemic copper questions remain
Repeated systemic copper exposure raises a mechanism-based question about copper balance. This is a theoretical concern, not a documented toxicity finding in people using injected GHK-Cu.
FDA status
Injectable GHK-Cu is not FDA-approved
Copper Tripeptide-1 can appear in topical cosmetics, whose ingredients generally do not receive FDA premarket drug approval. That cosmetic fact does not authorize or approve GHK-Cu as an injectable drug.7
FDA’s page, content current as of April 22, 2026, lists GHK-Cu for injectable routes under “nominated but withdrawn.” FDA’s safety note remains beside the entry. Withdrawal does not change the substance-specific and patient-specific requirements that apply to compounding.8
GHK-Cu is not on FDA’s finalized list of additional bulk substances for patient-specific compounding.9 Compounded drugs are not FDA-approved.10 Promise Peptides is currently taking waitlist sign-ups. Joining is not a medical request and no prescription comes from it.
A prescription route
Promise is currently accepting waitlist signups. Joining is not a treatment request and does not result in a prescription. If treatment visits open, any treatment request would require clinical review; prescribing and pharmacy fulfillment would remain separate decisions.
Start on Promise’s GHK-Cu page
It shows what the treatment involves and its current availability.
Answer the GHK-Cu questionnaire
A licensed provider reviews health history, medicines and goals, and can decline. Not everyone qualifies.
Pharmacy review is a separate step
A prescription does not guarantee preparation or dispensing. A pharmacy must separately determine whether it can fulfill the prescription under the applicable requirements.
A prescription does not make injectable GHK-Cu FDA-approved or turn topical and cell research into evidence for the injectable route; it reflects a clinician’s review of an individual case.
GHK-Cu at Promise
Read the treatment information and view the current waitlist.
Join the Promise waitlistPeak may earn money when readers become Promise patients.
Joining does not guarantee future treatment availability. Availability would depend on the treatment, state, clinical review and separate pharmacy review.
Questions
What is the difference between GHK and GHK-Cu?
GHK is the three-amino-acid peptide. GHK-Cu is that peptide bound to a copper ion, which changes its chemical identity and is the form described as Copper Tripeptide-1.
What is Copper Tripeptide-1?
It is the cosmetic ingredient name for GHK-Cu. Evidence from topical cosmetics does not establish the safety or effectiveness of an injectable prescription.
Is injectable GHK-Cu FDA-approved?
No. FDA specifically tracks the injectable route in its compounding safety material, and no FDA-approved injectable GHK-Cu drug exists.8
Sources
- Maquart FX, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Lett. 1988;238:343-346. PubMed 3169264
- Pickart L. The human tri-peptide GHK and tissue remodeling. J Biomater Sci Polym Ed. 2008;19:969-988. PubMed 18644225
- Hostynek JJ, et al. Human skin penetration of a copper tripeptide in vitro as a function of skin layer. Inflamm Res. 2011;60:79-86. PubMed 20721598
- Pickart L, et al. GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. Biomed Res Int. 2015;2015:648108. PubMed 26236730
- Lee WJ, et al. Efficacy of a complex of 5-aminolevulinic acid and glycyl-histidyl-lysine peptide on hair growth. Ann Dermatol. 2016;28:438-443. PubMed 27489425
- Mortazavi SM, et al. Topically applied GHK as an anti-wrinkle peptide: advantages, problems and prospective. BioImpacts. 2025. PubMed 39963574
- U.S. Food and Drug Administration. FDA authority over cosmetics: how cosmetics are not FDA-approved, but are FDA-regulated.
- U.S. Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of April 22, 2026.
- U.S. Food and Drug Administration. Bulk drug substances used in compounding under section 503A of the FD&C Act.
- U.S. Food and Drug Administration. Compounding and the FDA: Questions and Answers.