Is 1% Copper Peptide Actually 1%?

There is a thread on r/TheOrdinarySkincare that has been quietly bothering me for months. Someone asks a simple question about a copper peptide serum they have been using: "are they referring to 1% pure GHK-Cu active or 1% copper peptide complex slash raw solution?"

Nobody in the thread can answer it. Not the person who asked, not the people replying, and not, as far as I can tell, the brand.

That question is the most important thing in this entire category, and almost nobody is talking about it. So let's talk about it.

Two things a percentage can mean

When a skincare label says 1% of an ingredient, you naturally assume it means the finished product is 1% that ingredient by weight. Sometimes that is exactly what it means.

Sometimes it means something else entirely.

GHK-Cu is rarely bought by manufacturers as a pure powder. It is usually supplied as a pre dissolved solution, because the raw peptide is difficult to work with and expensive to handle in tiny quantities. Those solutions come at standard concentrations, and the two you see most often are 1,000 ppm and 10,000 ppm.

Parts per million is just a smaller unit than percent. 10,000 ppm is 1%. 1,000 ppm is 0.1%.

Now watch what happens.

The maths

A formulator buys a 10,000 ppm GHK-Cu solution. That solution is 1% actual peptide and 99% water and carrier.

They add 1% of that solution to their cream.

The finished cream is now 1% of a solution that was itself 1% peptide. So the actual GHK-Cu content is 0.01%. One hundred parts per million.

The label can still say 1% copper peptide. It is not a lie in the sense a lawyer would recognise. It is describing the input, not the output.

A different brand buys the same solution and formulates to a finished concentration of 1% pure GHK-Cu. Their cream contains 10,000 ppm of the actual molecule.

Same number on the front. A hundredfold difference in the jar.

Why nobody clears this up

Partly because there is no rule forcing anyone to. Cosmetic labelling requires an ingredient list in descending order of weight. It does not require you to state the concentration of anything, and the moment you volunteer a number you get to choose which number you mean.

Partly because the ambiguity is commercially useful. If your competitor is quietly stating the input percentage and you state the output percentage, your number looks smaller and you lose the shelf comparison. The incentive runs in exactly the wrong direction.

And partly, honestly, because most people buying skincare have never been told this is a thing. You cannot ask a question you do not know exists.

Can you tell from the ingredient list?

Barely.

You can look at where Copper Tripeptide-1 sits in the INCI list. Ingredients are listed in descending order by weight down to 1%, and below 1% they can appear in any order. So if the peptide is buried near the end, after the preservative, you know it is under 1% of the formula. That tells you something.

What it does not tell you is whether that sub 1% figure is the peptide or a solution containing the peptide.

There is one other tell, and it is the one I find most useful. GHK-Cu is blue. The copper is what makes it blue, and it is a fairly saturated colour at meaningful concentrations. A copper peptide product that is completely colourless is worth a question. Not proof of anything on its own, because opacifiers and pigments exist, but worth a question.

What to actually ask

If you want a real answer from a brand, the question that works is not "how much copper peptide is in this."

It is this:

Is the stated percentage pure active Copper Tripeptide-1 in the finished product, or a percentage of a raw solution? And what is the finished concentration in ppm?

A brand that knows will answer in one line. A brand that does not know, or would rather you did not, will send you a paragraph about their proprietary complex.

Ask for the certificate of analysis while you are at it. Not the manufacturing certificate, which just says the factory follows good practice. The assay, which says what is actually in the product.

What we do

Copper Theory states 1%, and by that we mean 1% pure active Copper Tripeptide-1 in the finished cream. Ten thousand parts per million of the molecule itself, not of something the molecule is dissolved in.

We chose 1% deliberately, and not because we could not afford more. That is a separate conversation and I have written about it separately, because the reasoning is more interesting than the number.

The reason we publish this at all is simple. If we are going to charge more than the cheapest copper peptide on the shelf, the difference has to be something you can check rather than something you have to take on faith.

One more thing

None of this makes concentration the only thing that matters. It is not even the most important thing.

GHK-Cu is water loving and positively charged, and skin is fatty and designed to keep things out. Measured on real skin, only a small fraction of what you apply gets past the surface at all. A well delivered 1% will outperform a badly delivered 3% every time, and there is published work showing exactly that.

But you cannot have that conversation until the first one is settled. So start with the number. Ask what it means. And notice who can answer.