# Facial creams and procollagen

> Facial creams at Luxurious Med Spa: the findings — Luxurious Med Spa examines GHK-Cu facial cream findings, procollagen response percentages and the limits of turning those figures into a preference.

The most attractive percentage in the cabinet needs its outcome attached.

## Subjects with increased procollagen synthesis

The [2025 topical GHK review](https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/) reports increased procollagen synthesis in 70% of GHK-Cu-treated subjects, versus 50% for vitamin C and 40% for retinoic acid. Procollagen is the precursor being measured in that comparison.

Read as a response count, the result interests me. Read as a percentage improvement in someone’s skin, it says something the outcome never measured. The 70% describes the share of subjects with an increase. It supplies no 70% increase in collagen quantity or reduction in wrinkle depth.

I initially wanted those figures to settle a contest between ingredients. They cannot carry quite so much. A count of responders leaves the size of each response open, and a preference for a facial cream reaches beyond this biological measure.

![Horizontal bars show increased procollagen synthesis in 70% of GHK-Cu subjects, 50% for vitamin C and 40% for retinoic acid](images/procollagen-response.svg)

*Share of subjects with increased procollagen synthesis, as reported in the [topical review](https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/); bar length shows response frequency.*

## Skin appearance in the reviews

The [2015 skin-regeneration review](https://pmc.ncbi.nlm.nih.gov/articles/PMC4508379/) describes placebo-controlled improvements in skin laxity, clarity, fine lines, wrinkle depth and density. These are the appearance-related outcomes that make the cream question worth asking in the first place.

I take those reported outcomes seriously. I also resist folding them into the procollagen comparison as though all the measurements were interchangeable. A biological response and a visible change can both matter while answering different questions.

Let firmness, fine lines and the feel of a formulation retain their separate identities: that account would persuade me more. “Better skin” is too roomy a conclusion for my taste. The pleasure of a cream is allowed to be a pleasure without carrying every claim about its ingredient.

## The formulation being tested

The [topical review’s delivery discussion](https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/) brings the cream itself back into focus. It treats poor skin permeability as a central problem and examines strategies intended to improve delivery. An ingredient’s name leaves that part of the object undescribed.

The finished formulation matters because the [skin-penetration problem](/skin-penetration) is physical. Changing how a peptide is presented to skin changes the experimental question. The most persuasive comparison would give the outcome and the preparation equal attention.

For the cell experiment that established a narrower reason for interest, return to [collagen synthesis](/collagen).

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Luxurious Med Spa is my cabinet of published research on copper-peptide skincare, not a med spa business, and nothing here is medical advice.