Copper Peptides (GHK-Cu): Benefits, Hype and How to Use Them

Copper peptides, usually GHK-Cu (copper tripeptide-1), are small copper-carrying peptides that lab studies link to collagen production and wound repair. Their claimed skincare benefits are firmer skin, fewer fine lines and more even tone. The human evidence is thinner than the marketing suggests: a handful of 12-week cream studies, mostly reported by researchers tied to copper peptide products, and no strong trials for hair.

Below we go through where GHK-Cu comes from, what the research does and doesn't show, the worries about mixing it with vitamin C, acids and retinol, the "copper uglies" story, and how it compares with other peptides. We finish with a simple way to use it.

What is GHK-Cu?

GHK-Cu is a three-amino-acid peptide (glycine, histidine, lysine) bound to a copper ion. It occurs naturally: a review in BioMed Research International reports that GHK is found in human plasma, saliva and urine, and that plasma levels fall from about 200 ng/mL at age 20 to about 80 ng/mL by age 60. In cosmetic chemistry it's classed as a carrier peptide, because its job is to deliver copper, which a review in Frontiers in Chemistry notes is an essential cofactor for lysyl oxidase, an enzyme involved in forming collagen and elastin. On an ingredient list, look for "copper tripeptide-1."

What are the benefits of copper peptides for skin?

The claimed benefits are firmer, denser skin with fewer fine lines and less mottled pigmentation, and most of the support comes from lab and wound-healing research. The 2015 review describes GHK as stimulating both the build-up and breakdown of collagen and glycosaminoglycans, and as accelerating wound healing of skin and other tissues in animal studies. A 2018 review by the same group adds that GHK increases collagen, elastin and glycosaminoglycan synthesis and supports dermal fibroblasts.

For faces, the 2015 review summarizes several placebo-controlled cream studies:

• A GHK-Cu facial cream used for 12 weeks by 71 women with mild to advanced photoaging improved laxity, clarity and fine lines and increased skin density.
• A GHK-Cu eye cream tested for 12 weeks on 41 women did better than both a placebo and a vitamin K eye cream on lines and wrinkles.
• In a 12-week study of 67 women aged 50 to 59, a GHK-Cu cream applied twice daily improved laxity, firmness, fine lines and mottled pigmentation.
• In a small one-month biopsy study on the thighs, collagen rose in 70% of women using GHK-Cu, compared with 50% using a vitamin C cream and 40% using retinoic acid.

Read those numbers with care. The reviews were written by researchers from the R&D department of Skin Biology, a commercial company, and the reference list shows the facial studies were presented at a dermatology meeting, in a university report and in a book chapter rather than published as full peer-reviewed trials. The 70% figure comes from a pilot study. None of this means copper peptides don't work; it means the evidence is promising but small and hard to check independently.

Does GHK-Cu get through the skin?

Probably some, but how much is still debated. The 2015 review states that GHK-Cu appears to pass the stratum corneum in amounts sufficient to activate regenerative effects, and that its permeability rises with pH. A 2025 review in Molecules is more cautious, calling GHK-Cu a fairly hydrophilic compound with limited permeation through the lipophilic stratum corneum and noting that liposome-based delivery has received little study. A general rule from dermatology applies here too: a cosmetic peptide only helps if it is stable in the formula, absorbed into the skin and active at the target.

Can I use copper peptides with vitamin C?

Most brands say to keep them apart, so use them at different times of day. The Ordinary, for example, advises avoiding its Multi-Peptide + Copper Peptides 1% Serum with direct acids, retinoids and strong antioxidants like vitamin C. Brands don't publish detailed data behind that advice, and we couldn't find a clinical study that tested the two together on facial skin. Splitting them costs you nothing, so the simplest plan is vitamin C in the morning and copper peptides in the evening, or the reverse. Our vitamin C serum guide explains which forms of vitamin C are which.

Can I use copper peptides with strong acids or retinol?

Keep copper peptides away from strong acid exfoliants, and alternate them with retinoids. The 2015 review reports that GHK was stable in water between pH 4.5 and 7.4 and is prone to breaking apart under oxidative stress. Exfoliating acid serums are formulated to be acidic, which takes the peptide outside the range that was tested. The Ordinary's copper serum itself is listed at pH 6.00 to 7.00.

Retinoids are a different case: there's no published chemistry argument we could verify, but The Ordinary lists retinoids among the products to avoid with its copper serum, and both are actives you'd want to judge one at a time. A practical schedule is retinoid on some nights and copper peptides on the others. For the full set of combinations to space out, see our guide to skincare ingredients not to mix, and for retinoid basics, retinol for beginners.

Are the "copper uglies" real?

The "copper uglies" is an online term for skin that looks rougher, duller or looser after heavy use of copper peptides. We couldn't find a single published study describing it, measuring it or explaining a mechanism, so treat it as an anecdote. That said, a reaction that makes your skin look worse is a reason to stop, whatever you call it. The Ordinary's directions say that if irritation occurs, rinse off, stop using the product and consult a physician, and recommend a patch test first.

If you want to try copper peptides, the AAD's patch test is a good starting point: apply the product twice daily for 7 to 10 days to a quarter-sized spot, such as the bend of your elbow, and only move to your face if nothing happens. Our guide on how to patch test skincare has the details. After that, start every other day and use a commercial product rather than mixing your own from powder.

Do copper peptides help hair growth?

The evidence for hair is early-stage and mostly not on GHK-Cu itself. A Seoul National University study tested a related complex, AHK-Cu, and found it stimulated the elongation of human hair follicles ex vivo and the growth of dermal papilla cells in vitro. That's useful lab work, but it isn't a trial on people's scalps. The 2018 review lists increased hair growth and thickness among GHK-Cu's effects, yet it's a review by researchers from a company R&D department, not a clinical trial. If you're losing hair, see a dermatologist: there are treatments with much stronger evidence, and the cause matters.

How do copper peptides compare with other peptides?

Copper peptides have the biggest lab literature, while signal peptides such as Matrixyl have cleaner published face trials. Here's the short version:

Our main guide to peptides in skincare covers the signal and neurotransmitter peptides in more detail.

How do I use a copper peptide serum?

1. Pick a finished product. For example, The Ordinary's Multi-Peptide + Copper Peptides 1% Serum combines GHK-Cu with several other peptides and costs $32.00 on the brand's US site as of October 2026.
2. Patch test for 7 to 10 days as described above.
3. Apply a few drops after cleansing, before moisturizer. The Ordinary's directions allow morning and evening use; starting once a day makes reactions easier to spot.
4. Keep it apart from vitamin C, acids and retinoids using the table above.
5. Wear sunscreen every morning and give it about 12 weeks, the length of the cream studies, before you decide.

Keep expectations in proportion. These are cosmetics, and under US law cosmetic products do not need FDA approval before they go on the market, so the "firming" and "repair" claims on a bottle haven't been reviewed by a regulator.

How can a selfie scan or ingredient scanner help?

Because copper peptide results are gradual, a consistent before-and-after record helps more than a mirror check. An app like Pori takes a selfie and gives an overall skin score with a breakdown that includes Anti-aging & Elasticity and Pigmentation & Tone, plus before/after comparison and progress charts, so you can see whether week 12 actually looks different from week 0. Pori's ingredient scanner (Pro) checks a barcode or label photo and flags each ingredient as beneficial, use with caution or avoid for your skin type, which is handy when a "copper" serum also lists acids or fragrance.

An app is not a diagnosis; it tracks how your skin looks. If a product leaves your skin red, sore or peeling, stop it and see a dermatologist if it doesn't settle.