glutathione stock solution L-Glutathione (Reduced Form) The Glutathione Protocol from PlexusDx is a compounded master antioxidant tripeptide available in two formulations — nasal spray or troche — at provider L-Glutathione reduced (GSH) | Antioxidant

PubMed PMID: 29602528

In the literature: GHK-Cu is a copper-binding tripeptide investigated for extracellular matrix remodeling pathways in in-vitro fibroblast cultures and animal skin biology models

Molecular Profiles of the BPC-157 and TB-500 Peptides BPC-157 TB-500 (Thymosin Beta-4) Storage, Handling, and Reconstitution of the BPC-157 + TB-500 Peptide Blend Store the lyophilized vial at -20 C (-4 F), sealed and protected from light and moisture

So what is GHK-Cu peptide used for, in plain terms

They found that standard aqueous solutions of AHK-Cu were ineffective because the hydrophilic peptide could not penetrate the sebum-rich environment of the hair follicle and was easily washed away during rinsing