# The research shelf

> Research shelf | Elite Hair Restoration — The Elite Hair Restoration reading list: human follicle work, a GHK combination hair-count trial, skin penetration and topical formulation research.

**Reading list**

The follicle paper, the combination trial and the delivery studies occupy different shelves for a reason.

## Follicles and hair counts

The [AHK-Cu paper on isolated human hair follicles and cultured cells](https://pubmed.ncbi.nlm.nih.gov/17703734/) is the place to start for the follicle experiment. The [trial of 5-aminolevulinic acid with GHK](https://pmc.ncbi.nlm.nih.gov/articles/PMC4969472/) supplies the human hair-count result discussed here.

I give the combination trial more weight for a claim about a change in people’s hair, while preserving the exact preparation in the conclusion. The isolated-follicle result is the closer look at a different copper peptide.

## Skin transport and tissue activity

The [human-skin penetration study](https://pmc.ncbi.nlm.nih.gov/articles/PMC3016279/) follows copper through skin layers. The [topical GHK review](https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/) considers the formulation problem from an anti-wrinkle perspective. The [GHK-Cu collagen-synthesis experiment](https://pubmed.ncbi.nlm.nih.gov/3169264/) supplies the separate fibroblast result.

For the argument built around each paper, return to [copper peptides](/copper-peptides), [the hair-count trial](/hair-count-trial) or [skin delivery](/skin-delivery).

## References

[1] The effect of tripeptide-copper complex on human hair growth in vitro https://pubmed.ncbi.nlm.nih.gov/17703734/
[2] Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth https://pmc.ncbi.nlm.nih.gov/articles/PMC4969472/
[3] Human skin penetration of a copper tripeptide in vitro as a function of skin layer https://pmc.ncbi.nlm.nih.gov/articles/PMC3016279/
[4] Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective https://pmc.ncbi.nlm.nih.gov/articles/PMC11830136/
[5] Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ https://pubmed.ncbi.nlm.nih.gov/3169264/

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At Elite Hair Restoration I weigh the published research on hair peptides in an editorial cabinet with no treatment business behind it, and none of these pages provides medical advice.