Getting GHK-Cu through skin

A culture dish puts a substance close to cells. A topical formulation faces a surface first. That extra journey deserves its own page.

The delivery problem

The anti-wrinkle review identifies poor permeability through the stratum corneum as a central problem for GHK. The stratum corneum is the outer skin layer. The review considers delivery strategies alongside the reported cosmetic effects.

This is the less photogenic half of the glow story, and I am unusually fond of it. A proposed action can sound impressive while the means of getting a substance to its intended setting remains difficult. Formulation brings the discussion back to material behaviour.

I am consequently more interested in a tested preparation than in an ingredient's reputation. That is a preference about evidence, rather than instructions for assembling a routine.

Excised human skin

In the human skin-penetration experiment, researchers measured copper passage through dermatomed skin and copper retained as a dermal depot over 48 hours. The study used human skin outside the body, with the analysis organised by skin layer.

The measured material was copper applied as a GHK-Cu tripeptide preparation. Precision about the measured material makes the experiment intelligible to me. A copper measurement alone leaves further questions about the peptide and its proposed biological action.

The experiment gives a delivery discussion something tangible: passage and retention in a defined skin model. Its outcome concerns penetration, with no assessment of wrinkles or satisfaction in people.

A glass diffusion chamber with a thin membrane held between its compartments — Constructed laboratory illustration for the skin-penetration discussion; this is an imagined apparatus.

Formulations in the review

The review of topical GHK evaluates palmitoylation and microneedle pretreatment as possible ways to improve delivery. Those are specific experimental strategies, and the chemically modified peptide deserves to retain its own identity.

Delivery work earns its place in this collection by retaining those differences. A preparation has its own composition and a test has its own setting. The interesting question is whether the finished preparation has evidence for the outcome being claimed, including the experience of the people to whom an appearance claim refers.

The finished preparation

The topical review puts the delivery problem beside the cosmetic findings. I welcome that untidy meeting of biology and material behaviour. An ingredient's proposed action has to be considered together with the preparation used to test it.

I reserve a place in the collection for preparations studied as a whole, with a defined outcome and clear conditions. The human skin findings return to appearance. The aging discussion asks how far the much larger preservation story can travel.