Lists of what GHK-Cu supposedly does tend to grow as they get copied. Somewhere past collagen and wound healing, most versions of the list pick up anti-anxiety activity. It is an unusual claim for a skincare ingredient, and it has a traceable source. It also now has a direct test, published in 2025, that points the other way.
This article covers GHK-Cu as a cosmetic ingredient. It is not medical advice, and nothing here has been evaluated by the FDA.
Key Takeaways
- The anti-anxiety claim comes from review articles, where it is listed among many attributed actions of GHK alongside anti-pain and anti-aggression activity [1][2].
- A 2025 study assessed GHK and several proline-containing analogues in the Vogel conflict test, a validated punished-behavior model of anxiety [3].
- The result for the peptide itself was explicit: GHK had no anxiolytic effect [3].
- Analogues did work. PGP and GHK-PGP produced effects at certain doses, and the authors proposed that the GHK-PGP effect comes from PGP acting in the absence of a blocking effect from GHK [3].
- This research involves systemic dosing in rodents. It has no bearing on a serum applied to the face, in either direction.
Where the Claim Comes From
Two widely cited review papers are the origin of most secondhand GHK claim lists. A 2014 review describes the tripeptide as improving wound healing and tissue regeneration, increasing collagen and glycosaminoglycans, stimulating decorin synthesis, increasing angiogenesis and nerve outgrowth, and possessing antioxidant and anti-inflammatory effects [2].
A 2018 review by the same lead author extends the list further, citing tissue repair across skin, lung, bone, liver, and stomach lining, multiple anti-cancer activities, suppression of NF-kappaB, lung protection, DNA repair, activation of the proteasome, and, in the same sentence, anti-anxiety, anti-pain and anti-aggression activities [1].
Reviews are a legitimate form of scientific writing, and these gather a large amount of genuine work. But a claim inside a review is only as strong as the primary study behind it, and a reader receiving the claim thirdhand from a product page has usually lost the ability to check which study that was. The anti-anxiety item is a good example, because it arrives compressed into three words in a list of roughly twenty items.
What a Real Anxiety Test Looks Like
Behavioural pharmacology has established paradigms for this, and the Vogel conflict test is one of the older ones. A thirsty animal is given access to water, and drinking is intermittently punished with a mild stimulus. The animal is then caught between a drive and a deterrent. Compounds that reduce anxiety characteristically increase the number of punished responses, because the conflict weighs less heavily.
The test is used precisely because it produces a directional, quantifiable outcome rather than an impression. Established anxiolytics increase punished responding in it, which gives the model its validity.
The 2025 Study and Its Result
In 2025, researchers used exactly this test to examine the anxiolytic effects of the peptide GHK-PGP and its proline-containing structural analogues. Five peptides were included: GHK, PGP, the combined GHK-PGP, GHK-GP, and GHK-P [3].
Including plain GHK as one of the five is what makes this study useful here, because it means the tripeptide was directly assessed in the same paradigm as the compounds of interest rather than assumed.
The finding was unambiguous. The peptide GHK had no anxiolytic effect, while PGP and GHK-PGP produced an anxiolytic effect at certain doses. GHK-P and GHK-GP also showed effects, which the authors read as indicating anxiolytic activity across various proline-containing sequences attached to GHK [3].
The Interpretation Is Sharper Than a Null Result
A null finding on its own usually means the study lacked sensitivity. That reading is not available here, because the same experiment detected effects in four of the five compounds tested. The method worked. GHK was the one that did nothing.
The authors went further. They proposed that the anxiolytic effect of GHK-PGP is determined by the action of PGP in the absence of the blocking effect of GHK [3]. That is a hypothesis rather than a demonstrated mechanism, and it should be read as one. But it is close to the opposite of the claim in circulation: in this experiment the active element was the proline-containing fragment, and GHK is proposed as something that can interfere with it.
Why This Matters Beyond One Claim
The useful lesson is not really about anxiety. It is about how a claim list behaves as it travels. An item enters a review as a compressed summary, gets copied into a secondary article, then appears on a product page with no citation at all. By that point nothing in its presentation distinguishes it from the well-supported items sitting next to it. Collagen stimulation in fibroblasts and anti-anxiety activity look identical in a bulleted list, despite resting on very different amounts of evidence.
When someone finally runs the specific test, the result can diverge from the list. That is what happened here, and it is a reason to treat long attribute lists for any single molecule with more suspicion than any one attribute on its own.
What This Does Not Say
Two boundaries are worth stating plainly. First, this research is systemic administration in rodents, evaluating peptides given to the animal rather than applied to skin. A copper peptide serum was never a candidate anxiety treatment, and nothing here changes how a topical product performs on skin.
Second, a single behavioural study does not permanently close a question. It is one test, one paradigm, one species. What it does do is replace an uncited claim with an actual measurement, and the measurement did not support the claim.
Anxiety is a real condition with effective evidence-based treatments. It is not something to address with a skincare ingredient, and anyone struggling with it is better served by a clinician than by an ingredient list.
Frequently Asked Questions
Has GHK-Cu been shown to reduce anxiety?
No. The one study to test GHK in a validated punished-behavior anxiety paradigm reported that GHK had no anxiolytic effect, while several proline-containing analogues did [3].
Why do so many sources list anti-anxiety as a GHK benefit?
It appears in review articles that compile a long list of attributed actions for the peptide [1], and lists like that get copied onward without the underlying evidence for each item being checked separately.
Could a copper peptide serum affect mood?
There is no evidence for that and no plausible route. This research gave peptides systemically to rodents, which has nothing in common with a cosmetic product applied to the surface of the skin.
What is PGP and why did it work?
PGP is the proline-glycine-proline tripeptide that was tested alongside GHK. It produced an anxiolytic effect at certain doses, and the study’s authors suggested the effect seen with the combined GHK-PGP peptide is driven by PGP rather than by GHK [3].
References
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences (2018). PMID 29986520 (authors affiliated with Skin Biology, a company that sells copper-peptide products)
- Pickart L, Vasquez-Soltero JM, Margolina A. GHK and DNA: Resetting the Human Genome to Health. BioMed Research International (2014). PMID 25302294
- Alferova ME, Bobyntsev II, Vorvul AO, Tenkova AN. Anxiolytic Effect of GHK-PGP Peptide and Its Structural Analogues in a Test with Punished Behavior. Bulletin of Experimental Biology and Medicine (2025). PMID 41511598
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for professional medical or dermatological advice. As an Amazon Associate we earn from qualifying purchases.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.