acetyl hexapeptide-8
The Peptides Behind the Peptide: What Else Is in koppā's GHK-Cu Serum
GHK-Cu is the reason koppā exists. It is not the only reason the serum works the way it does. Here is what else is in koppā's GHK-Cu 2% High Potency Serum, the water-light, fragrance-free 45 ml bottle built around it.
When people talk about our serum, they talk about the 2%: two per cent Copper Tripeptide-1, about 900 mg of GHK-Cu in a 45 ml bottle, the fourth ingredient on the label. That is the number we are proudest of, and the one we will keep putting first.
But a serum is a formula, not a single ingredient. Around the GHK-Cu sit six more named peptides, two forms of collagen, a four-part hydration system and two of the skin's own barrier lipids. Each was chosen for a job, and each has its own research record. This is the guide to all of them.
Which peptides are in the serum besides GHK-Cu?
The ingredient list names seven peptides: Copper Tripeptide-1 (GHK-Cu), Acetyl Hexapeptide-8, Palmitoyl Tetrapeptide-7, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Carnosine, Palmitoyl Tripeptide-5 and Acetyl Octapeptide-3. Add Hydrolyzed Collagen and Collagen and you have the nine-component peptide and collagen complex printed on the bottle.
They do not all do the same thing, and that is the point. Some are studied for collagen signalling and firmness, some for the look of expression lines, one for protecting skin proteins from glycation. Together they cover more of what skin longevity means than any one peptide can.
Has a clinical study tested these peptides together?
In February 2026, researchers published a study in the International Journal of Cosmetic Science on a serum built around two peptides that are also in koppā's formula: Acetyl Hexapeptide-8 and Dipeptide Diaminobutyroyl Benzylamide Diacetate, often sold as SYN-AKE.
The work combined laboratory testing on skin samples with two clinical studies, one of 50 people looking at static lines and skin quality, and one of 42 people looking at expression lines. After 12 weeks, the authors reported clinical-score improvements of 35% to 69% across different types of static lines, and 10% to 13% for expression lines, all statistically significant.
Two things matter about that result. First, it is recent human research on a combination of two exact ingredients in our serum, which is more than most supporting peptides ever get. Second, the studied serum also contained gluconolactone, niacinamide and laminaria extract, so the numbers belong to that formula. We cite it because it shows these peptides have been tested together in people.
What is each ingredient studied for?
GHK-Cu (Copper Tripeptide-1), 2%
The copper peptide studied for collagen synthesis since 1988 and in human skin since 1998. In skin fibroblasts it increased collagen and glycosaminoglycan production; in human studies it was associated with increased collagen in skin biopsies, improved skin density, thickness and firmness over 12 weeks, and better measured smoothness than a leading peptide complex in a double-blind trial. koppā's GHK-Cu is synthetic Copper Tripeptide-1.
Acetyl Hexapeptide-8 (Argireline)
A signal peptide studied for the look of expression lines. An early study found smoother-looking skin around the eyes after 30 days, and a randomised, placebo-controlled trial in 60 people reported improved eye-area lines over four weeks. Reviews call the evidence encouraging, with skin penetration the open question, which is one reason we pair it with other peptides rather than relying on it alone.
Dipeptide Diaminobutyroyl Benzylamide Diacetate (SYN-AKE)
A small synthetic peptide developed for the look of expression lines, and the second of the two peptides in the 2026 study above. Most of its earlier data comes from its supplier; the 2026 work is the most significant published human research involving it.
Acetyl Octapeptide-3
A longer relative of Acetyl Hexapeptide-8, used in formulas aimed at expression lines. Its data comes mainly from its supplier, so we describe it as part of the complex rather than making standalone claims for it.
Palmitoyl Tripeptide-5 and Palmitoyl Tetrapeptide-7
Two matrikine-type signal peptides associated with collagen-supporting pathways and skin conditioning. Palmitoyl Tetrapeptide-7 is half of the well-known Matrixyl 3000 pairing. They give the formula a second collagen-support story alongside GHK-Cu.
Carnosine
An antioxidant dipeptide with research on glycation, the slow reaction between sugars and skin proteins such as collagen that is part of how skin structure changes with age. Laboratory and skin-sample research shows carnosine can reduce glycation markers. It is the ingredient in the formula most directly tied to skin longevity.
Hydrolyzed Collagen and Collagen
Applied to the skin, collagen conditions the surface and holds water there, for skin that feels smooth and supple. The deeper collagen story is the job GHK-Cu and the signal peptides are studied for.
What do the hydrators and ceramides do?
Peptides get the attention, but the ingredients you feel first are the hydrators. Glycerin, trehalose and betaine bind water; polyglutamic acid and sodium hyaluronate hold it at the surface. Hyaluronic acid in creams has improved skin hydration and roughness in a 76-woman, 60-day study. Together they help skin look plumper and smoother through the day, which also makes lines deepened by dryness look less noticeable.
Ceramide EOP and Ceramide NP are lipids your own barrier is built from. Panthenol has human data on faster barrier recovery after irritation, and allantoin and dipotassium glycyrrhizate keep skin comfortable. This is what makes the serum a skin-quality formula rather than a peptide shot.
Which ingredients answer which concern
| What you notice | Ingredients working on it |
|---|---|
| Firmness and skin structure | GHK-Cu, Palmitoyl Tripeptide-5, Palmitoyl Tetrapeptide-7 |
| Expression lines | Acetyl Hexapeptide-8, SYN-AKE, Acetyl Octapeptide-3 |
| Dryness-related fine lines and plumpness | Glycerin, trehalose, betaine, polyglutamic acid, sodium hyaluronate |
| Dryness and comfort | Ceramide EOP, Ceramide NP, panthenol, allantoin |
| Long-term skin maintenance | GHK-Cu, carnosine, the barrier lipids |
What koppā adds to the research
The studies in this article tested each ingredient in research formulas. What koppā adds is the documented input: 2% GHK-Cu on the label, about 900 mg of it in a 45 ml bottle at US$8.33 per 100 mg, the supplier's 99% minimum purity specification for the raw material, a pH of 5.5 to 6.0, and the full ingredient list on the product page. Of the eight copper peptide serums in our serum comparison, that is the most stated GHK-Cu per dollar.
GHK-Cu remains the hero, and the rest of the formula is built to support it.
Where koppā fits in your routine
The serum is the treat step: it goes on clean skin first and absorbs quickly with a non-greasy finish. Follow it with a moisturiser, such as koppā's GHK-Cu Advanced Capsule Cream with 5% niacinamide, and finish mornings with SPF 30+. For the full order of steps with other actives, see our guide to layering GHK-Cu with other ingredients, and for what the number on the label means, what 2% GHK-Cu means.
See the GHK-Cu Serum and its full ingredient list, then start with three to four drops on clean skin, face and neck, morning and night.
Frequently asked questions
Is Argireline the same as Botox?
No. Acetyl Hexapeptide-8 is a cosmetic peptide studied for how expression lines look when applied to the skin. It is not an injectable and does not paralyse muscles.
Are more peptides always better?
No. A long list is not evidence in itself. What matters is whether each peptide has a defined job and some research behind it, and whether the hero ingredient is present at a stated amount. That is how we built the complex.
Does the serum contain niacinamide?
No. Niacinamide is in koppā's Advanced Capsule Cream, at 5%, the level studied in women over 12 weeks. Using the serum and cream together gives you both.
Can I use the serum with other peptide products?
Yes. Peptides layer well with hyaluronic acid, ceramides, niacinamide, moisturisers and sunscreen. Keep low-pH vitamin C and exfoliating acids to the other end of the day.
How do I use koppā's GHK-Cu serum, and what does it cost?
Apply 3 to 4 drops of koppā's GHK-Cu 2% High Potency Serum to clean skin on the face and neck, morning and night, before moisturiser. It costs $75 for 45 ml, 50% more than a 30 ml serum, and the 2% GHK-Cu concentration is stated on the label.
The short version
koppā's GHK-Cu 2% High Potency Serum is built around 2% GHK-Cu, with six more peptides, Hydrolyzed Collagen and Collagen, a hydration system and two ceramides around it. Each has a defined job, from firmness and the look of expression lines to hydration and comfort. Two of the peptides, Acetyl Hexapeptide-8 and SYN-AKE, were tested together in people in a 2026 study. To start, apply 3 to 4 drops to clean skin, face and neck, morning and night.
Sources
- Zhu et al. The effect of a serum containing acetyl hexapeptide-8, dipeptide diaminobutyroyl benzylamide diacetate and gluconolactone on skin biomarkers, wrinkles and skin texture: ex vivo and clinical studies. International Journal of Cosmetic Science, 2026. PubMed[1]
- Blanes-Mira C, et al. A synthetic hexapeptide (Argireline) with antiwrinkle activity. International Journal of Cosmetic Science, 2002. PubMed[2]
- Wang Y, et al. The anti-wrinkle efficacy of argireline, a synthetic hexapeptide, in Chinese subjects: a randomized, placebo-controlled study. American Journal of Clinical Dermatology, 2013. PubMed[3]
- Maquart FX, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Letters, 1988. PubMed[4]
- 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. PMC[5]
- Pavicic T, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Journal of Drugs in Dermatology, 2011. PubMed[6]
- Proksch E, Nissen HP. Dexpanthenol enhances skin barrier repair and reduces inflammation after sodium lauryl sulphate-induced irritation. Journal of Dermatological Treatment, 2002. PubMed[7]
Sources and further reading
- PubMed pubmed.ncbi.nlm.nih.gov
- PubMed pubmed.ncbi.nlm.nih.gov
- PubMed pubmed.ncbi.nlm.nih.gov
- F X Maquart et al. (1988). Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Letters. DOI: 10.1016/0014-5793(88)80509-x pubmed.ncbi.nlm.nih.gov
- Loren Pickart et al. (2018). Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences. DOI: 10.3390/ijms19071987 pmc.ncbi.nlm.nih.gov
- PubMed pubmed.ncbi.nlm.nih.gov
- PubMed pubmed.ncbi.nlm.nih.gov
