Is There a Dupe for Expensive Copper Peptide Serums?
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We sell a mid-priced copper peptide serum, so we are not neutral. The method problem below is real regardless of who points it out.
Why dupe finders fail on this category specifically
Most "dupe" pages are auto-generated. They compare two ingredient lists, count how many entries overlap, and score the match as a percentage. Some use a Dice coefficient, some just count shared entries against a threshold.
That method works reasonably for a moisturiser, where the formula as a whole is the product.
It fails badly for copper peptides, because ingredient lists do not contain amounts. Two serums can share 90% of their ingredients and differ by a factor of 2,000 in the one ingredient that gives the category its name. In our dataset, disclosed concentrations run from 5 ppm to 4%. An overlap score cannot see any of that.
It also means a genuinely well-matched product can be excluded on a technicality. A short 6-ingredient formula will never score a high overlap against a 49-ingredient one, no matter how similar the active dose is.
What to compare instead
Three things, in order:
- Stated concentration. If both products state one, you have a real comparison. If either does not, you do not have a dupe, you have a guess.
- Formulation pH. A matching concentration at the wrong pH is not a match, because the copper dissociates from the peptide and the number stops describing the bottle.
- Base type. Aqueous versus silicone changes whether the active reaches skin at all.
The actual matches
From 23 products checked against brand pages on 24 August 2026.
Looking for a cheaper NIOD CAIS3
CAIS3 is $62 for 15ml, so $4.13 per ml, stating 1% GHK-Cu plus 1% GHK at pH 5.7 to 6.7.
The Ordinary Multi-Peptide + Copper Peptides 1% at $1.07 per ml is the obvious candidate, and it is roughly a quarter of the price with a published pH of 6.0 to 7.0. The gap is that its 1% is ambiguous about what it attaches to. Same parent company.
Ours is $2.00 per ml with an unambiguous 1% GHK-Cu at pH 6.0. Half the price of CAIS3, double The Ordinary. We do not carry the separate free GHK that CAIS3 does.
Looking for a cheaper Aseir Custom
Royal Blue Serum is $149.99 stating 3%. If concentration is what you are paying for, Neurogan at a stated 4% is higher for $40 to $55. That is a genuine match on the headline spec at a third of the price.
Neither states a pH, so neither can be checked on the variable that decides whether the concentration survives.
Looking for the cheapest thing that still discloses
Asterwood, $21.99 for 1oz, states 0.10% inside the ingredient list. Good Molecules, $12 for 30ml, states 5 ppm. Both are honest about being low. Neither is a dupe for a 1% product, and neither pretends to be.
The uncomfortable part
You cannot dupe a product that does not disclose. Nine of the 23 we checked state no concentration, including all four Skin Biology products. If you are trying to match one of those, there is no basis for the comparison, and any site telling you otherwise is scoring ingredient overlap and calling it a match.
Related
- The disclosure index, the underlying dataset.
- Ranked by price per ml.
- Alternatives to The Ordinary.
Corrections to support@amide.skin.