What Does 2% GHK-Cu Mean? Concentration Explained

2%

In the serum

Two grams in every hundred grams of formula

0.5%

Cream and balm stick

Encapsulated in the cream, water-free in the balm

0.9 g

Per 45 ml bottle

Which is why a few drops covers the face

Blue

Intact copper complex

Green or brown means it has changed

The number

What a percentage actually measures

Three things to know before you compare two bottles by their numbers.

A percentage on a cosmetic label is weight for weight: 2% GHK-Cu is two grams of the peptide in every hundred grams of product. So a 45 ml serum at 2% carries roughly twenty times the peptide of the same bottle at 0.1%. That part is simple.

What the number can't tell you is how much of that peptide is still intact, whether it reaches the skin, or whether the formula around it is something your face will tolerate. Those are the questions the next section is about.

What the science says

What the science saysGHK-Cu / Copper Tripeptide-1

Is a higher concentration better?

Not automatically. The evidence says the peptide is active at low levels, and untested past a point.

Two findings frame this. In cell culture, fibroblasts responded to GHK-Cu at nanomolar concentrations, far below anything in a serum¹. And the two reviews that gather the human work on topical GHK-Cu describe facial studies of creams and serums at cosmetic concentrations without establishing a dose above which results improve³⁴. Skin-penetration work on human skin samples shows the peptide reaches and stays in the skin layers², which is a point about the ingredient, not about any one bottle.

Put together: the peptide is active at low levels, higher concentrations have not been shown to do more past a point, and no published trial compares 0.5% against 2% on faces. A dish of cells is not a face, so nobody should read that as a case for a trace amount either. It is why we say a stated number matters more than a big one, and why the choice between our 2% serum and 0.5% cream is about texture and tolerance, not about which one works.

What's established

Activity at very low concentrations in cell studies¹; penetration into the skin layers on human skin samples².

What isn't

An optimal topical concentration. The reviews don't settle one³⁴, and no trial compares two on faces.

What that means

Read for a stated concentration, intact blue colour and a plain formula. Then pick the texture your skin will tolerate every day.

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

A hand lifting the serum from beside the capsule cream and balm stick — A few drops covers the face2% GHK-Cu · About 0.9 g in a 45 ml bottle

Our formulas

Why we chose 2% for the serum, and 0.5% for the rest

Two concentrations, on purpose.

2% in the serum

The highest concentration in the range, in the lightest texture, for people who want the most GHK-Cu per application and can tolerate a strong active. It's the product we'd point a first-timer to who already uses actives.

0.5% in the capsule cream

Encapsulated GHK-Cu with 5% niacinamide and squalane, in a moisturiser. For dry or cautious skin, and for the nights you want the peptide without the intensity.

0.5% in the balm stick

Water-free, with eight peptides alongside the GHK-Cu, for neck, jaw, hands and dry patches where a serum doesn't stay put.

Every koppā product page states its GHK-Cu concentration and full ingredient list. If a brand's page doesn't, ask them. If they won't say, that is your answer.

Why we keep it topical

Real people, real skin, nothing you can't check.

Compare all four

We're real people too. We feel the pull of the biggest number on the label, because the pressure to look good and to perform is intense. But our health is everything, and we want a number we can stand behind, stated where you can see it.

That's why koppā only makes topical GHK-Cu: on the skin, where the human research was done, in formulas with the concentration and the full ingredient list on the label. Nothing you can't check, and nothing you can't stop.

Start with the 2% serum, the capsule cream or the balm stick, or take all three as the Protocol. The research behind them is on the Science page, and the questions people ask next are answered here: copper peptide injections, are copper peptides safe and copper peptides before and after.

Koppā GHK-Cu serum — 2% copper peptide serum for face

Step 1, treat · For this question GHK-Cu 2% High Potency SerumConcentrated peptides for firmer, smoother-looking skin.$75Shop

Koppā Beauty copper peptide cream with GHK-Cu

Step 2, nourish GHK-Cu Advanced Capsule CreamCapsule-released peptides for deep, lasting hydration.$70Shop

Copper peptide balm stick by Koppā Beauty

Step 3, seal GHK-Cu Face + Body Balm StickTarget fine lines and dryness, from face to body.$45Shop

Koppā copper peptides skincare trio with GHK-Cu

All three, for less The GHK-Cu ProtocolYour complete peptide routine, for less.$175 ~~$190~~Shop

2% in the serum
Two grams in every hundred, spread water-light on the cheek.

0.5% in the capsule cream
Encapsulated GHK-Cu in a cream that doubles as your moisturiser.

0.5% in the balm stick
Water-free, so the peptide stays where you put it.

Three textures
Sheer serum, capsule cream and matte balm, side by side.

Reading a label

What a concentration claim can and can't tell you

Compare	What it tells you	What it doesn't
The number	How much peptide is in the formula by weight.	Whether the peptide is still intact, or whether it was ever GHK-Cu rather than a different copper compound.
"Highest" or "strongest"	That the brand chose a high number.	Whether your skin will tolerate it, or whether it's better than a lower one. The published reviews don't settle an optimal topical concentration³⁴.
Colour	Intact GHK-Cu is blue; the deeper the blue, generally the more copper complex is present.	A serum that has turned green or brown has changed, whatever the label says.
Ingredient list order	Whether the peptide sits high in the list or right at the bottom.	The exact amount, unless the brand states it separately.
Price per bottle	What you'll pay.	Anything about the formula. Cheap and expensive serums both range from 0.1% to several percent.

The number

What it tells you: How much peptide is in the formula by weight.
What it doesn't: Whether the peptide is still intact, or whether it was ever GHK-Cu rather than a different copper compound.

"Highest" or "strongest"

What it tells you: That the brand chose a high number.
What it doesn't: Whether your skin will tolerate it, or whether it's better than a lower one. The published reviews don't settle an optimal topical concentration³⁴.

Colour

What it tells you: Intact GHK-Cu is blue; the deeper the blue, generally the more copper complex is present.
What it doesn't: A serum that has turned green or brown has changed, whatever the label says.

Ingredient list order

What it tells you: Whether the peptide sits high in the list or right at the bottom.
What it doesn't: The exact amount, unless the brand states it separately.

Price per bottle

What it tells you: What you'll pay.
What it doesn't: Anything about the formula. Cheap and expensive serums both range from 0.1% to several percent.

Ready to start? Shop now, $75 Or the Protocol, $175

The checklist

How to read a copper peptide label

Five questions, in the order to ask them.

01
Is the concentration stated?
Is the concentration stated? If not, it's probably low or the brand doesn't want to say.
02
Is it GHK-Cu?
Is it GHK-Cu (copper tripeptide-1)? Some products list copper in another form, or a peptide without copper. Look for "Copper Tripeptide-1" on the INCI list.
03
Is the formula plain?
Is the formula plain? Fragrance, alcohol and a long list of extras give sensitive skin more to react to than the peptide does.
04
Is it blue?
Is it blue? A blue formula is a sign of intact copper complex. Watch the colour over the life of the bottle.
05
What do you have to take on trust?
Is there anything you'd have to take on trust? Look for what testing a brand says it does and which document backs it. Our Testing page says exactly what we hold and what each document covers.

Ready to start? Shop now, $75 Or the Protocol, $175

The serum

Koppā GHK-Cu High Potency Serum, a 45 ml 2% copper peptide serum in a blue glass dropper bottle

The serum

2% GHK-Cu, and the number is on the bottle.

koppā's serum is 2% GHK-Cu with a nine-peptide complex in a fragrance-free, silicone-free base. The concentration and the full ingredient list are on the product page, not in a claim. If you want the higher concentration, this is it; if you'd rather ease in, the capsule cream and balm stick carry 0.5%.

01

2% GHK-Cu

Stated on the bottle and the product page.

02

45 ml

A full size, not a 30 ml bottle.

03

Nine peptides

GHK-Cu with a defined peptide complex, listed in full.

Shop the serum, $75 The full Protocol, $175

2% GHK-Cu, stated on the label.

If you're starting

2% GHK-Cu, stated on the bottle.

koppā's serum is 2% GHK-Cu with a nine-peptide complex, in a fragrance-free, silicone-free base. The concentration and the full ingredient list are on the product page, not in a claim. If you want the higher concentration, this is it; if you'd rather ease in, the capsule cream and balm stick carry 0.5%.

Fragrance-free, silicone-free
Cruelty free
Full ingredient list and GHK-Cu concentration on every product page
Free shipping over $100

$75

GHK-Cu 2% High Potency Serum

Shop now, $75

Or take all three as the Protocol, $175

Free shipping over $100. See all four products

Customer feedback

From koppā customers.

Customer feedback on koppā products.

9 customer reviews

Shop the serum

“Been using it about 6 weeks now. Didn't notice much the first couple weeks, but my skin looks noticeably smoother around my cheeks and my makeup sits better. Will repurchase.”

Sarah M.koppā customer

FAQ

Questions about GHK-Cu concentration

Is 2% GHK-Cu a lot?

Yes. It's at the high end for a leave-on cosmetic. Many serums use well under 1%, and some don't state a number at all.

What is the strongest copper peptide serum?

Whatever bottle prints the highest number, which tells you less than it sounds. The research doesn't establish that more is better past a point³⁴, and cell studies show activity at very low concentrations¹. Look for a stated concentration, intact blue colour and a formula your skin will tolerate.

Is a higher concentration better?

Not automatically. It's more peptide per application, which suits people who tolerate strong actives. For sensitive or dry skin, 0.5% in a cream base is often the better daily choice.

Why is the serum 2% but the cream only 0.5%?

Different jobs. The serum is the concentrated step; the cream is the moisturiser that carries the peptide gently, with niacinamide and squalane. Used together they're the routine; used alone, each is a complete product.

How much GHK-Cu is in a 45 ml bottle at 2%?

About 0.9 grams of the copper peptide in the whole bottle, by weight. That's why three or four drops covers the face.

The formulas

Four formulas. Find your next step.

Two concentrations across four formulas, each stated on the label with the full ingredient list.

Prices and stock update live.

For this question

GHK-Cu 2% High Potency Serum

Concentrated peptides for firmer, smoother-looking skin.

$75

In stock

Shop now

Step 2, nourish

GHK-Cu Advanced Capsule Cream

Capsule-released peptides for deep, lasting hydration.

$70

Preorder

Shop now

Step 3, seal

GHK-Cu Face + Body Balm Stick

Target fine lines and dryness, from face to body.

$45

In stock

Shop now

The Koppā GHK-Cu Protocol: copper peptide serum, capsule cream and balm stick together on a dark navy background

The Protocol

The GHK-Cu Protocol

Your complete peptide routine, for less.

$175$190 separately

Preorder

Shop now

Save $15 versus buying separately

Sources

References

Research on GHK-Cu the ingredient, not on koppā's finished formulas. Where a study was run in cells or on skin samples rather than on people, we say so in the text.

1.Badenhorst T, Svirskis D, Merrilees M, Bolke L, Wu Z. Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters. Journal of Aging Science. 2016;4:166. Read the paper
2.Hostynek JJ, Dreher F, Maibach HI. Human skin penetration of a copper tripeptide in vitro as a function of skin layer. Inflammation Research. 2011;60(1):79-86. Read the paper
3.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;19(7):1987. Read the paper
4.Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International. 2015;2015:648108. Read the paper

What does 2% GHK-Cu mean? The full concentration guide, in the journal Is your copper peptide serum oxidised? How to tell, in the journal The science behind GHK-Cu

Still not sure?

Ask us about an ingredient, a concentration or how to fit GHK-Cu into your routine. We're real people on the other end, and we'd rather you asked than guessed. If you're managing a diagnosed skin condition, a dermatologist is the right person to ask first.

Shop the Protocol, $175 Ask a question How our formulas are tested The research behind GHK-Cu

Page updated 29 September 2026