What seems to be a true difference, though, is that the salt form is more stable, easier to formulate and cheaper so it pops up more often on the ingredient lists
There may be a potential for interactions or side effects
15 Being a powerful antioxidant, glutathione plays a critical role in several metabolic pathways: DNA and protein synthesis, amino acid transport, enzyme activation, immune system function, scavenging free radicals eg hydrogen peroxide, cofactor in Phase I cytochrome P450 enzyme-mediated detoxification, amino acid translocation across cell membranes, detoxification of xenobiotics, maintenance of sulfhydryl groups of proteins, mitochondrial function and maintenance of mitochondrial DNA, catalysis of exchange reactions and many more
Ann Clin Psychiatry 5:1015 Stahl SM (2007) Novel therapeutics for depression: l-methylfolate as a trimonoamine modulator and antidepressant-augmenting agent