It has low bioavailability because the tripeptide is the substrate of proteases (peptidases) of the alimentary canal, and due to the absence of a specific carrier of glutathione at the level of the cell membrane
New England Journal of Medicine Zheng Z et al
In the evaluation of immobilization carriers and of the effects of temperature, Tukeys test was used to identify significant differences between groups
Sections (5 mm) were stained with Safranin-O/Fast Green and hematoxylin and eosin
It just sits there
SEE HOW PEPTIDES CAN HELP HAIR REGROWTH Peptides for Hair Growth at a Glance Most directly researched peptides: GHK-Cu and AHK-Cu Common topical ingredients: Biotinoyl tripeptide-1 and acetyl tetrapeptide-3 Potential benefits: Follicle support, scalp conditioning, reduced inflammation, stronger hair, and healthier growth-cycle signaling Typical delivery methods: Leave-on scalp serums, professional scalp treatments, shampoos, conditioners, and provider-guided therapies Expected timeline: Several months rather than several weeks Main limitation: Large human trials comparing peptides with established hair-loss treatments remain limited Less likely to help: Areas where follicles have been permanently destroyed or replaced by scar tissue Do Peptides Help With Hair Growth