Is 4% GHK-Cu Better Than 1%? Neurogan and Aseir Custom
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We sell a 1% product, so we have an obvious interest in the answer to this. Read accordingly, and note that the mechanism below is not something we invented.
Who states what
| Product | Stated | Price | Per ml |
|---|---|---|---|
| Neurogan GHK-Cu Hair & Scalp Serum | 4% (2,400mg / 60ml) | $55 | $0.92 |
| Neurogan GHK-Cu Face & Neck Serum | 4% (1,200mg) | $51 | not stated |
| Neurogan GHK-Cu Neck & Face Serum | 4% | $40 | not stated |
| Aseir Custom Royal Blue Serum | 3% | $149.99 | not stated |
| Aseir Custom Sky Blue Cream | 3% / 30ml | $149.99 | $5.00 |
Credit where due: both brands state a number, which puts them ahead of the nine products in our dataset that state nothing. Neurogan also gives an absolute milligram figure alongside the percentage, which almost nobody does.
The mechanism that decides the answer
Intuition from acids does not transfer here, and this is the crux.
With an exfoliating acid, more concentration removes more surface. Roughly linear until you hit a tolerance ceiling. So "stronger is stronger" is a reasonable heuristic there.
GHK-Cu is not removing anything. It is a signalling molecule, and signalling is receptor-mediated. Once receptors are saturated, adding more does not produce a proportionally larger response. The message is already being received at full volume; saying it louder does not change what the cell does.
1% is generally treated as the saturation threshold, which is why most of the topical literature sits there.
What higher concentration does change
Not nothing. It changes how hard and how long the remodelling machinery runs.
Remodelling has two halves: clearing old matrix and building new. Both scale with the signal. Push a high concentration continuously and the clearing side can outpace your own synthesis rate, which shows up as skin that firmed for six weeks then went soft and dull. That is copper uglies, and it is a dosing problem rather than a bad reaction.
So at 3% or 4%, cycling stops being advisable and becomes necessary. Thirty days on, thirty off. If you buy a high-concentration product and run it continuously for months, you can end up worse off than when you started.
The honest case for high concentration
It is not that there is no case. Structured short protocols at higher concentration are a legitimate approach, and some people respond better to a stronger stimulus with a longer rest. Skin Biology's product ladder is built on a version of that logic.
What we would push back on is the implication that 4% is straightforwardly four times better than 1%, because that is not how receptor-mediated signalling works, and it is the reading the numbers invite.
What we would actually check
None of the five products above states a formulation pH. At any concentration, if the pH is wrong the copper dissociates from the peptide and the number on the label describes something that no longer exists in the bottle. A stated 4% at an unstated pH is not obviously better than a stated 1% at a stated 6.0.
Concentration is one of six specs, and on its own it settles less than it appears to. The other five.
Related
- What percentage actually matters, the full version.
- The 30/30 cycling protocol.
- The disclosure index.
Corrections to support@amide.skin.