The FDA advises against their use in people with a personal or family history of medullary thyroid carcinoma (MTC), in those with Multiple Endocrine Neoplasia type 2 (MEN2), or in patients with severe gastroparesis or past serious allergic reactions
This, combined with their limited capacity to synthetize glutamine suggests that adequate functioning of these cells in the neonatal period might be partially dependent on dietary-derived glutamine
Observational studies identify associations, not causation
Vitamin C enhances glutathione efficacy and boosts collagen synthesis, while hydrolyzed collagen peptides are easily absorbed to support skin elasticity and reduce the appearance of fine lines
Keiser AA, Matazel KS, Esser MK, Feifel D, Prus AJ
doi: 10.1186/s13195-014-0073-2 92 DiasVJunnEMouradianMM