Hexapeptide-48 Hcl

Hexapeptide-48 HCl is a small synthetic signaling peptide typically used at very low concentrations (generally well under 1%) in anti-aging/soothing formulations and is not pH-dependent like exfoliating acids. Available safety and patch-test experience with cosmetic peptides suggests a low rate of irritation or sensitization, with most reactions more often attributable to the overall formula rather than the peptide itself. Because it is a hydrochloride salt and still a bioactive peptide (rare idiosyncratic reactions are possible in highly compromised skin), I rate it as very gentle rather than inert. Safety Notes: Hexapeptide-48 HCl is a specialty signaling peptide typically supplied as a diluted aqueous/glycerin solution, so finished-product usage in commercial leave-on serums and eye/face creams is often very low (down to ~0.0001% active when brands include it as part of multi-peptide blends or at trace ‘label claim’ levels). High-strength consumer-available leave-on treatments that position a single peptide as a hero ingredient generally top out around ~0.1% active due to cost, solubility/stability in water phases, and diminishing returns above typical peptide dosing. It is uncommon in rinse-off products; when used, levels are usually at the low end because of limited skin contact time.