Glutathione Precursors Glutathione Precursor Complex, Swanson, 60 Capsules SWU542 Every time you exercise your body generates oxidative stress as a natural byproduct of muscle contraction and energy production. At moderate levels that is a healthy signal. But when exercise intensity exceeds Opt1 imports CoA precursors as glutathione mixed disulfides ScienceDirect NAC [N AcetylCysteine] is a precursor of Glutathione. PICTURE: Glutathione is made from three amino acids and cysteine is one of them