The first joins the amino acids glutamate and cysteine to make gamma-glutamylcysteine (GGC) and the second adds another glycine molecule to make glutathione
Dhaliwal JS, Rosani A, Saadabadi A
Orozco L, Soler R, Morera C, Alberca M, Sanchez A, Garcia-Sancho J: Intervertebral disc repair by autologous mesenchymal bone marrow cells: a pilot study
NOWL-Carnitine is the purest form, clinically tested, and vegetarian (non-animal sourced)
Also studied was the combined application of N G -nitro-L-arginine methylester (L-NAME) (5 mg/kg i.v.), a competitive inhibitor of endothelium nitric oxide (NO)-generation and the NO-precursor L-arginine (200 mg/kg i.v.) (D-arginine was ineffective)