is glutathione an enzyme Glutathione-Related Enzymes and Proteins: A Review Methionine and glutathione metabolism. Enzymes:

Preclinical studies suggest ALA may help defend neurons against oxidative stress, support synaptic function, and maintain healthy levels of glutathione, a critical antioxidant in brain cells.12 25 Importantly, ALA can cross the blood-brain barrier, making it a promising candidate for addressing conditions where oxidative stress or mitochondrial dysfunction play a role

The frequency and dosing of Glutathione injections depends on the condition being treated

Interestingly, strong similarities to the mammalian system have been observed, which proves the correctness of the green liver concept (Sandermann 1994)

You'll most likely see this ingredient near the end of an ingredient list