glutathione-s-transferase General reaction catalyzed by glutathione S-transferases PDB-101: Molecule of the Month:

10.1177/2515690X211036875 J Evid Based Integr Med

Research indicates that oral glutathione undergoes significant breakdown during digestion, with proteolytic enzymes in the gastrointestinal tract cleaving the peptide bonds that hold the three amino acids together

Peptide combinations incorporating GHK-Cu with matrikines, neurotransmitter-affecting peptides, or other specialty peptides continue to proliferate in cosmeceutical markets, though clinical validation of these complex combinations generally lags behind their commercial availability

If your peptide calculator shows you are working with a particularly sensitive compound, err on the side of colder storage and shorter shelf-life assumptions