Evidence review

Copper peptide serums compared: ingredients and evidence

Compare eight copper peptide serums by peptide identity, disclosed concentration, supporting ingredients and research. Koppā brings 2% GHK-Cu, six supporting peptides and two ceramides together in a 45 mL water-light serum.

Choosing a serum? Our main guide is The best copper peptide serums of 2027, compared.

By Chantelle, co-founder of KoppāPublished by Koppā. We make the Koppā products in this comparison.Updated 6 October 2026

Explore Koppā serum · $75 See the comparison

A stripe of blue copper peptide serum across a freckled cheek

The short answer

How should you choose a copper peptide serum?

Choose a copper peptide serum by its full formula, disclosed concentration and the step you want it to fill. Koppā is our choice for a lightweight daily serum that combines 2% GHK-Cu, six supporting peptides, two ceramides and hydration in a 45 mL bottle.

The table separates formula facts from research. GHK-Cu has laboratory evidence and human cosmetic research, including a double-blind facial trial³⁷. Use the product notes to compare texture, supporting ingredients and the evidence each brand publishes.

The comparison

Eight copper peptide serums, ingredient by ingredient

We make koppā, so it's first and we say so. Every other brand's details come from its own US product page, checked on 6 October 2026. Ingredient lists were copied word for word, and where a brand doesn't say something, we write "Not stated".

Serums compared

Full ingredient list read for each

Head-to-head trials

Between any two serums here

Randomised trials of GHK-Cu

Counted by a 2026 systematic review of 20 studies

Sources

Each one opened and checked

01
Our pick
koppāGHK-Cu 2% High Potency Serum

Copper peptide, as stated
2% GHK-Cu
Size
45 ml
Your current price
$75
Best for
A stated GHK-Cu percentage in a fragrance-free, multi-peptide formula
Copper Tripeptide-1 is fourth on the ingredient list, after water, trehalose and glycerin. Six more defined peptides follow: Acetyl Hexapeptide-8, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-5, Acetyl Octapeptide-3, Dipeptide Diaminobutyroyl Benzylamide Diacetate and Carnosine. Acetyl Hexapeptide-8 has its own placebo-controlled trial¹⁵.
The base adds panthenol, which has human data on barrier repair¹⁹, along with ceramides EOP and NP, polyglutamic acid and sodium hyaluronate. There's no fragrance, silicone or EDTA.
What koppā adds to that research is a stated 2% concentration on the label, a complete ingredient list, supplier documentation specifying at least 99% purity for the raw GHK-Cu, and a pH of 5.5 to 6.0. The references in this section describe GHK-Cu and supporting-ingredient research. Formula details and supplier documentation are identified separately.
Why it's our pick
- A stated 2% GHK-Cu concentration
- US$1.67 per ml at the checked price
- Copper Tripeptide-1 fourth on the list
- Six supporting peptides plus panthenol and ceramides
- No fragrance, silicone or EDTA in the formula
- 45 ml, the largest bottle with a stated GHK-Cu figure here
Worth knowing
- pH 5.5 to 6.0; raw GHK-Cu certified by its supplier, batch by batch
- Three to four drops, morning and evening
- As for every serum here, the studies cited tested the ingredients
Shop the serum, $75 Or take all three as the Protocol, $175
02
Lowest price with a stated %
The OrdinaryMulti-Peptide + Copper Peptides 1% Serum

Copper peptide, as stated
"Copper Peptides 1%", in the name; basis not stated
Size
30 ml
Price
$32
Best for
A low-cost multi-peptide serum
Copper Tripeptide-1 is fourth, like ours, followed by seven more peptides, including the pair sold as Matrixyl 3000 (Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7) and Palmitoyl Tripeptide-38. The page gives the pH as 6.00 to 7.00.
The 1% is in the product's name, and the page doesn't say whether it is GHK-Cu alone.
Worth knowing
- Formerly called "Buffet" + Copper Peptides 1%
- Silicone-free, per the brand
- The brand says not to combine it with direct acids, direct vitamin C, retinoids or strong antioxidants
theordinary.com
03
Study numbers given
NIODCopper Amino Isolate Serum 3 1:1

Copper peptide, as stated
1% GHK-Cu, plus 1% GHK
Size
15 ml or 30 ml
Price
$62 or $93
Best for
A stated 1% GHK-Cu, with study details
The copper ingredient is listed as Tripeptide-1 Copper Acetate, fourth, and the brand calls it 1% GHK-Cu. Alongside it is 1% GHK peptide without copper (Tripeptide-1 Acetate), plus Tripeptide-29, Myristoyl Nonapeptide-3, Tripeptide-2 and Acetyl Tetrapeptide-2. The page gives the pH as 5.7 to 6.7.
NIOD is the only brand here that says how many people its study included and for how long: 31 people over 4 and 8 weeks, and 32 over 12 weeks, twice a day. The page doesn't say whether there was a placebo.
Worth knowing
- Silicone-free, per the brand
- Use morning and night, as the first step after cleansing
niod.com
04
Most peptides
Peach & LilyCopper Peptide Pro Firming Serum

Copper peptide, as stated
0.2% copper peptide
Size
30 ml
Price
$49
Best for
Many peptides at a lower copper peptide level
States 0.2% copper peptide, with Copper Tripeptide-1 sixth and twelve more peptides, including Palmitoyl Pentapeptide-4, the peptide with the best published trial in this group¹³. The long list of plant extracts and six forms of hyaluronic acid makes it the most complex formula here.
Worth knowing
- The brand gives percentages from a "brand study", without the number of people or how long it ran
- Use morning and night, per the brand
peachandlily.com
05
Lowest price per ml
COSRXThe Blue Peptide Bakuchiol Plump Glow Serum

Copper peptide, as stated
0.5% copper peptide
Size
50 ml
Price
$27
Best for
A low-cost copper peptide with bakuchiol
States 0.5% copper peptide plus 0.25% bakuchiol, with niacinamide fifth on the list. Niacinamide has its own split-face trial¹⁸. Copper Tripeptide-1 comes 11th, after dimethicone. The list also includes Disodium EDTA, a chelator that in theory competes for copper; no study has measured that effect in a finished serum¹².
Worth knowing
- Shown as backordered on the brand site
- The list includes alcohol and dimethicone
- Avoid the eye area, per the brand
cosrx.com
06
Two copper forms
BiossanceSqualane + Copper Peptide Rapid Plumping Serum

Copper peptide, as stated
Copper Tripeptide-1 + Copper PCA; % not stated
Size
50 ml
Price
$69
Best for
Copper peptide with squalane and ectoin
Copper Tripeptide-1 is seventh and Copper PCA twelfth. Copper PCA is a different copper compound, and there's no study comparing it with GHK-Cu. Ectoin, ninth, has its own vehicle-controlled trial¹⁶.
The brand cites a 28-day study of 31 women aged 30 to 65 and gives percentages of participants who improved.
Worth knowing
- No concentration given
- One full dropper on face and neck, per the brand
biossance.com
07
Copper plus growth factors
INNBEAUTY ProjectElastic Skin

Copper peptide, as stated
"6% Copper Peptides + Bio-Hacking Peptides" (combined)
Size
30 ml
Price
$52
Best for
Copper peptide inside a broader firming formula
Copper Tripeptide-1 is 11th, after squalane, sunflower oil and wild yam extract. The 6% on the label combines copper and other peptides, so it isn't a GHK-Cu figure. The growth-factor peptides are the most distinctive part; a systematic review of topical growth factors found only modest improvements²⁰.
Worth knowing
- Fragrance-free, per the brand
- The brand quotes wrinkle and elasticity percentages at 12 weeks without the number of people
innbeautyproject.com
08
Premium price
Allies of SkinCopper Tripeptide & Ectoin Advanced Repair Serum

Copper peptide, as stated
"1% Copper Tripeptide Complex", "2% Copper Lysinate Complex"
Size
1 fl oz (29.6 ml)
Price
$199
Best for
Copper with ectoin, on a bigger budget
The percentages are of supplier complexes, not of pure ingredients. The ingredient list on the brand's own site doesn't include Copper Tripeptide-1 or ectoin, but a retailer's list for the same product shows both, so check the box. The brand gives participant numbers (19 to 35) and study lengths (2 to 8 weeks) for several of its claims.
Worth knowing
- Formulated without silicones or added fragrance, per the brand
- The brand says to wait 10 to 15 minutes between this and vitamin C, retinoids or acids
allies.shop

Also checked, not compared: Naturium's and Medik8's peptide serums use Copper Palmitoyl Heptapeptide-14, not GHK-Cu. Neova's Power Defense lists Bis (Tripeptide-1) Copper Acetate but no concentration. We couldn't read Good Molecules' own page; Target lists 0.10% Copper Tripeptide-1. Mad About Skin's site wasn't live.

Formulation

What does a copper peptide serum's ingredient list tell you?

Seven things you can read off any label. We applied them to every serum above, ours included.

What we found / Why it matters
Signal	What we found	Why it matters
A stated percentage	Two brands state a GHK-Cu figure (koppā 2%, NIOD 1%). Peach & Lily (0.2%) and COSRX (0.5%) state a copper peptide figure where Copper Tripeptide-1 is the only copper peptide. The others give a blend, a supplier complex, or nothing.	It's the only number you can compare across brands. A percentage of a "complex" includes the supplier's carrier, so it's always more than the active itself.
Position on the list	4th (koppā, The Ordinary, NIOD), 6th (Peach & Lily), 7th (Biossance), 11th (COSRX, INNBEAUTY).	Ingredients above 1% are listed in descending order, so position is the best clue when no percentage is given. Below 1% they can appear in any order.
Which copper	Copper Tripeptide-1 in most. NIOD lists Tripeptide-1 Copper Acetate, Neova Bis (Tripeptide-1) Copper Acetate, Biossance adds Copper PCA, and Allies of Skin lists Copper Lysinate/Prolinate.	The research is on GHK-Cu. There's no study comparing it with copper PCA or copper lysinate, and in one cell study free copper alone reproduced one of GHK-Cu's effects²⁷.
Other peptides	From one (Allies of Skin) to twelve (Peach & Lily). koppā has six, The Ordinary seven.	Only a few peptides have published placebo-controlled trials: Palmitoyl Pentapeptide-4¹³ and Acetyl Hexapeptide-8¹⁵. A long list isn't evidence in itself²⁶.
pH	koppā states 5.5 to 6.0, The Ordinary 6.00 to 7.00, NIOD 5.7 to 6.7. The others don't state it.	In a lab test, GHK-Cu stayed stable between pH 4.5 and 7.4 and broke down under alkaline and oxidising stress²⁵.
Chelators	COSRX lists Disodium EDTA. koppā's serum doesn't contain it.	Chelators like EDTA bind copper, so in theory they compete with the peptide for it¹². No study has measured this in a finished serum, so treat it as a question, not a defect.
Fragrance and silicone	No fragrance in any of the eight, per their ingredient lists. Dimethicone in COSRX.	Fragrance is a common cause of contact reactions. Copper peptides are often chosen by people who can't tolerate retinoids, so a fragrance-free base makes sense.

A stated percentage

What we found: Two brands state a GHK-Cu figure (koppā 2%, NIOD 1%). Peach & Lily (0.2%) and COSRX (0.5%) state a copper peptide figure where Copper Tripeptide-1 is the only copper peptide. The others give a blend, a supplier complex, or nothing.
Why it matters: It's the only number you can compare across brands. A percentage of a "complex" includes the supplier's carrier, so it's always more than the active itself.

Position on the list

What we found: 4th (koppā, The Ordinary, NIOD), 6th (Peach & Lily), 7th (Biossance), 11th (COSRX, INNBEAUTY).
Why it matters: Ingredients above 1% are listed in descending order, so position is the best clue when no percentage is given. Below 1% they can appear in any order.

Which copper

What we found: Copper Tripeptide-1 in most. NIOD lists Tripeptide-1 Copper Acetate, Neova Bis (Tripeptide-1) Copper Acetate, Biossance adds Copper PCA, and Allies of Skin lists Copper Lysinate/Prolinate.
Why it matters: The research is on GHK-Cu. There's no study comparing it with copper PCA or copper lysinate, and in one cell study free copper alone reproduced one of GHK-Cu's effects²⁷.

Other peptides

What we found: From one (Allies of Skin) to twelve (Peach & Lily). koppā has six, The Ordinary seven.
Why it matters: Only a few peptides have published placebo-controlled trials: Palmitoyl Pentapeptide-4¹³ and Acetyl Hexapeptide-8¹⁵. A long list isn't evidence in itself²⁶.

pH

What we found: koppā states 5.5 to 6.0, The Ordinary 6.00 to 7.00, NIOD 5.7 to 6.7. The others don't state it.
Why it matters: In a lab test, GHK-Cu stayed stable between pH 4.5 and 7.4 and broke down under alkaline and oxidising stress²⁵.

Chelators

What we found: COSRX lists Disodium EDTA. koppā's serum doesn't contain it.
Why it matters: Chelators like EDTA bind copper, so in theory they compete with the peptide for it¹². No study has measured this in a finished serum, so treat it as a question, not a defect.

Fragrance and silicone

What we found: No fragrance in any of the eight, per their ingredient lists. Dimethicone in COSRX.
Why it matters: Fragrance is a common cause of contact reactions. Copper peptides are often chosen by people who can't tolerate retinoids, so a fragrance-free base makes sense.

Choose your daily copper peptide step Shop now, $75 Or the Protocol, $175

The evidence

The evidenceGHK-Cu / Copper Tripeptide-1

How strong is the evidence for GHK-Cu?

Consistent in the lab and on people. Here it is level by level, from cells to faces.

GHK is a three-amino-acid peptide (glycine, histidine, lysine) first isolated from human plasma in 1973¹. It binds copper tightly, and the copper complex helps carry copper into cells². On ingredient lists, GHK-Cu is Copper Tripeptide-1, and the complex is why these serums are blue.

You'll often read that blood GHK falls from about 200 ng/mL at age 20 to 80 ng/mL at 60. The figure is reported in the reviews of GHK's skin research⁹.

In cells: consistent

In fibroblast cultures, GHK-Cu raised collagen synthesis from very low concentrations, peaking at 1 nanomolar³. It raised dermatan and heparan sulfate (but not hyaluronic acid)⁴, and increased MMP-2 along with its inhibitors TIMP-1 and TIMP-2²⁷.

In animals: supportive

In rat wounds, GHK-Cu increased type I collagen, glycosaminoglycans and decorin, a proteoglycan that organises collagen fibres⁵.

On skin samples: it gets in

On human skin in the lab, a 0.68% solution delivered copper into and through the skin over 48 hours, with a depot left in the skin layers⁶. The test measured copper, not the intact peptide.

In people: small and mixed

The one peer-reviewed controlled facial trial we found: 40 women, 8 weeks, split-face⁷. A GHK-Cu serum reduced wrinkle volume 31.6% more than a Matrixyl 3000 product and 55.8% more than its base.

What independent reviews say

Reviews of GHK-Cu describe collagen synthesis in cells and, on people, firmer, denser skin and softer-looking fine lines over 12 weeks³⁴⁷.

What a stated percentage tells you

A stated percentage makes the concentration basis visible: koppā states 2% GHK-Cu in 45 ml, while some compared serums state 1% or do not disclose a GHK-Cu percentage. Concentration is one comparison point and does not predict finished-product results.

Shop now, $75 Or take all three as the Protocol, $175 Explore the science of GHK-Cu

A drop of blue Koppā GHK-Cu copper peptide serum beside a swirl of the serum texture — Copper Tripeptide-1Glycine, histidine, lysine and one copper ion

Key studies

The GHK-Cu studies, one by one

What each study was, what it found and what limits it. A cell study tells you a mechanism exists, but only a trial on faces tells you what a serum does.

Design / Finding
Study	Design	Finding
Maquart 1988	In vitro: human fibroblasts³	Collagen synthesis rose from 10⁻¹² M and peaked at 10⁻⁹ M, independent of cell number.
Wegrowski 1992	In vitro: human fibroblasts⁴	Glycosaminoglycans peaked at 1 to 10 nM and fell back at higher doses. Hyaluronic acid was unchanged.
Siméon 2000	Animal: rat wound chambers, plus rat fibroblasts⁵	More type I collagen, glycosaminoglycans and decorin in wounds.
Hostynek 2010	Ex vivo: human skin, 0.68% solution, 48 h⁶	Copper penetrated, and a depot stayed in the skin.
Badenhorst 2016	Human: 40 women, randomised, double-blind, split-face, 8 weeks⁷	Wrinkle volume 31.6% lower than a Matrixyl 3000 product and 55.8% lower than the base. Randomised and double-blind.
Pickart & Margolina 2018	Review, by GHK's discoverer⁹	Reports 12-week studies in 71 and 41 women: firmer, denser skin and fewer fine lines.

Maquart 1988

Design: In vitro: human fibroblasts³
Finding: Collagen synthesis rose from 10⁻¹² M and peaked at 10⁻⁹ M, independent of cell number.

Wegrowski 1992

Design: In vitro: human fibroblasts⁴
Finding: Glycosaminoglycans peaked at 1 to 10 nM and fell back at higher doses. Hyaluronic acid was unchanged.

Siméon 2000

Design: Animal: rat wound chambers, plus rat fibroblasts⁵
Finding: More type I collagen, glycosaminoglycans and decorin in wounds.

Hostynek 2010

Design: Ex vivo: human skin, 0.68% solution, 48 h⁶
Finding: Copper penetrated, and a depot stayed in the skin.

Badenhorst 2016

Design: Human: 40 women, randomised, double-blind, split-face, 8 weeks⁷
Finding: Wrinkle volume 31.6% lower than a Matrixyl 3000 product and 55.8% lower than the base. Randomised and double-blind.

Pickart & Margolina 2018

Design: Review, by GHK's discoverer⁹
Finding: Reports 12-week studies in 71 and 41 women: firmer, denser skin and fewer fine lines.

Choose your daily copper peptide step Shop now, $75 Or the Protocol, $175

Supporting ingredients

What else is in these serums, and what's the evidence?

A serum is a formula, not one ingredient. Here's the best published human evidence for the other actives on these labels.

In which serums / Best evidence we found
Ingredient	In which serums	Best evidence we found
Acetyl Hexapeptide-8	koppā, The Ordinary, Peach & Lily, COSRX, Allies of Skin	A 4-week randomised, placebo-controlled trial in 60 people improved eye-area wrinkle roughness, with no change on placebo¹⁵. It's thought to dampen nerve signals to muscles¹⁴.
Palmitoyl Pentapeptide-4	Peach & Lily	In a 12-week split-face, placebo-controlled trial in 93 women, it reduced wrinkles and fine lines. The study was run by the maker¹³.
Palmitoyl Tripeptide-1 and Tetrapeptide-7	The Ordinary (both); koppā (Tetrapeptide-7); Peach & Lily (Tripeptide-1)	Sold together as Matrixyl 3000. Judged safe as used in cosmetics²³.
Other signal peptides	Most serums: e.g. Palmitoyl Tripeptide-5, Acetyl Octapeptide-3, Palmitoyl Tripeptide-38	Mostly supplier data. A review of these peptides found only 6 of 15 studies used a placebo²⁶.
Hyaluronic acid	Almost all	In 76 women over 60 days, 0.1% hyaluronic acid improved hydration and elasticity versus placebo; only lower molecular weights reduced wrinkle depth¹⁷.
Panthenol	koppā, Biossance, COSRX, INNBEAUTY, Allies of Skin	Sped up barrier repair and reduced redness after irritation, versus its base¹⁹.
Niacinamide	COSRX, INNBEAUTY	5% for 12 weeks, split-face in 50 women: fewer fine lines, blotchiness and sallowness, and better elasticity¹⁸.
Ectoin	Biossance, Allies of Skin	A randomised, vehicle-controlled trial in 104 women at 2%; the abstract reports preference and no side effects, but no effect sizes¹⁶.
Growth-factor peptides	INNBEAUTY	A systematic review of 33 studies found modest improvement and no difference in the three comparative trials²⁰.

Acetyl Hexapeptide-8

In which serums: koppā, The Ordinary, Peach & Lily, COSRX, Allies of Skin
Best evidence we found: A 4-week randomised, placebo-controlled trial in 60 people improved eye-area wrinkle roughness, with no change on placebo¹⁵. It's thought to dampen nerve signals to muscles¹⁴.

Palmitoyl Pentapeptide-4

In which serums: Peach & Lily
Best evidence we found: In a 12-week split-face, placebo-controlled trial in 93 women, it reduced wrinkles and fine lines. The study was run by the maker¹³.

Palmitoyl Tripeptide-1 and Tetrapeptide-7

In which serums: The Ordinary (both); koppā (Tetrapeptide-7); Peach & Lily (Tripeptide-1)
Best evidence we found: Sold together as Matrixyl 3000. Judged safe as used in cosmetics²³.

Other signal peptides

In which serums: Most serums: e.g. Palmitoyl Tripeptide-5, Acetyl Octapeptide-3, Palmitoyl Tripeptide-38
Best evidence we found: Mostly supplier data. A review of these peptides found only 6 of 15 studies used a placebo²⁶.

Hyaluronic acid

In which serums: Almost all
Best evidence we found: In 76 women over 60 days, 0.1% hyaluronic acid improved hydration and elasticity versus placebo; only lower molecular weights reduced wrinkle depth¹⁷.

Panthenol

In which serums: koppā, Biossance, COSRX, INNBEAUTY, Allies of Skin
Best evidence we found: Sped up barrier repair and reduced redness after irritation, versus its base¹⁹.

Niacinamide

In which serums: COSRX, INNBEAUTY
Best evidence we found: 5% for 12 weeks, split-face in 50 women: fewer fine lines, blotchiness and sallowness, and better elasticity¹⁸.

Ectoin

In which serums: Biossance, Allies of Skin
Best evidence we found: A randomised, vehicle-controlled trial in 104 women at 2%; the abstract reports preference and no side effects, but no effect sizes¹⁶.

Growth-factor peptides

In which serums: INNBEAUTY
Best evidence we found: A systematic review of 33 studies found modest improvement and no difference in the three comparative trials²⁰.

Choose your daily copper peptide step Shop now, $75 Or the Protocol, $175

Concentration and stability

Does a higher GHK-Cu percentage work better?

Not proven. Here's what the chemistry does and doesn't tell you.

Fibroblasts respond to GHK-Cu at nanomolar concentrations³⁴, while a 1% serum is millimolar, about a million times stronger. Most of it has to get through the outer layer of skin first⁶, so serums use far more than cells need. What a stated percentage gives you is a way to compare, and a way to know what you're paying for: 2% is about 0.9 g of GHK-Cu in a 45 ml bottle.

On stability, GHK-Cu held up in solutions from pH 4.5 to 7.4 at 60 °C, and broke down under alkaline and oxidising stress²⁵. Formaldehyde-releasing preservatives also degrade it, which is why GHK-Cu formulas avoid them.

The "never mix copper peptides with vitamin C" rule is mostly theory. Free copper oxidises ascorbic acid, but the copper inside GHK-Cu proved resistant to that reaction in a lab study²⁴. Using them at opposite ends of the day is a sensible precaution, not a proven necessity. Several brands above advise it, and koppā doesn't forbid the pairing.

Safety

Are copper peptide serums safe?

For most people, yes.

Copper is a very weak skin sensitiser. A review of copper hypersensitivity puts the weighted average at 3.8% among people tested because of suspected symptoms²¹. We found no published case of allergy to GHK-Cu itself. In the split-face trial, 1 of 40 people reacted to both test products⁷.

The industry's Cosmetic Ingredient Review judged Tripeptide-1 and its metal salts safe as used in cosmetics²³. Pregnancy and breastfeeding haven't been studied, so ask your doctor or midwife first.

See our full safety guide for side effects and the "peptide sensitivity".

Method

How we compared these serums

Written by Chantelle, co-founder of koppā. Here is exactly how we compared them.

Brands in their own words

Ingredient lists, sizes, prices, percentages and directions come from each brand's own US product page on 6 October 2026, copied verbatim. Where we had to use a retailer, we say so.

Every study opened

Each paper was checked on PubMed, PMC or the publisher's site.

Evidence graded, not just cited

We label every finding as cells, animals, skin samples or people, with the number of people and the length.

What koppā documents

koppā states its pH (5.5 to 6.0) and holds a supplier certificate of analysis for its raw GHK-Cu. Formula documentation and published ingredient research are identified separately. No brand paid to be here, outbound links earn us nothing, and we didn't star-rate anything. Spot an error? Tell us and we'll fix it and date the change.

Our verdict

Which copper peptide serum should you choose?

Choose by formula and routine fit, then check the full ingredient list.

For a stated GHK-Cu percentage in a fragrance-free, multi-peptide formula: koppā's GHK-Cu 2% serum, which we make.

For the most study detail on the product page: NIOD's Copper Amino Isolate Serum 3 1:1, at 1%.

For the lowest price per ml: COSRX, at a stated 0.5%, or The Ordinary, if you want more peptides. Compare price per ml separately from concentration and complete formula.

koppā 2% GHK-Cu Copper Peptide Serum, 45 mL blue glass dropper bottle: concentrated copper peptide serum with ceramides and hyaluronic acid for hydration, barrier support and firmer-looking skin

If you're choosing

2% GHK-Cu, and it says so on the bottle.

koppā's serum is 2% GHK-Cu, fourth on the ingredient list, with six supporting peptides, panthenol and ceramides in a water-light base with no fragrance or silicone. 45 ml, three or four drops morning and night.

2% GHK-Cu, stated
Fragrance-free, silicone-free
Cruelty free
Free US shipping over US$100

$75

koppā 2% GHK-Cu Copper Peptide Serum

Shop now, $75

Or take all three as the Protocol, $175

Free US shipping over US$100. See all four products

FAQ

Questions about copper peptide serums and the evidence

What is the most scientifically backed copper peptide serum?

Compare the full formulation, disclosed concentration, supporting ingredients and product-specific documentation. Research references in this guide identify the study type and the formulation tested. The ingredient GHK-Cu has decades of cell and animal research, plus human trials including a randomised, double-blind facial trial⁷. Judge a serum by its label: a stated GHK-Cu percentage, the named copper ingredient, supporting ingredients and fragrance status. We make koppā, which states 2% GHK-Cu, lists Copper Tripeptide-1 fourth and adds six supporting peptides.

Does GHK-Cu actually work on wrinkles?

The evidence is consistent. In cells, it raises collagen and other skin-matrix components³⁴. In a peer-reviewed, randomised, double-blind facial trial, a GHK-Cu serum reduced wrinkle volume more than a Matrixyl 3000 product and its base over 8 weeks, in 40 women⁷. Earlier 12-week cream studies reported denser, firmer skin and fewer fine lines⁴.

What percentage of GHK-Cu should a serum have?

There is no proven ideal. Serums here state 0.2% to 2%, and no study compares these retail concentrations on faces. A stated figure improves transparency, but it is not a measure of results. Compare concentration, complete formula, bottle size and price as separate factors.

Is The Ordinary's copper peptide serum GHK-Cu?

It contains Copper Tripeptide-1, which is GHK-Cu, fourth on its ingredient list, alongside seven other peptides. The "1%" is in the product's name, and the brand's page doesn't say whether it refers to GHK-Cu alone.

Is Copper PCA the same as copper peptides?

No. Copper PCA is copper bound to pyrrolidone carboxylic acid, not to the GHK peptide, and the GHK-Cu research doesn't transfer to it. We found no study comparing the two directly.

Can I use a copper peptide serum with vitamin C or retinol?

Many people do, at different times of day. The concern with vitamin C is that free copper oxidises it, but the copper in GHK-Cu resisted that reaction in a lab study²⁴, so the rule is a precaution rather than proven. Follow the brand's directions; several advise against layering them directly. Our retinol guide covers routines.

Why are copper peptide serums blue?

The colour is the copper-peptide complex itself. A deeper blue usually means more copper complex, but colour isn't a reliable way to compare brands.

Is this comparison sponsored?

No. No brand paid to be included, and the links to other brands earn us nothing. We make the first serum on the list, which is why we say so at the top and in the verdict.

Sources

References

Peer-reviewed research and primary sources, numbered as cited above. Where a study was in cells, animals or skin samples rather than people, the text says so.

1.Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nature New Biology. 1973;243(124):85-87. PMID 4349963. Read the paper
2.Pickart L, Freedman JH, Loker WJ, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature. 1980;288(5792):715-717. doi:10.1038/288715a0. Read the paper
3.Maquart FX, Pickart L, Laurent M, Gillery P, Monboisse JC, Borel JP. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Letters. 1988;238(2):343-346. doi:10.1016/0014-5793(88)80509-x. Read the paper
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