The small thiol present in highest concentration in the cytoplasm is glutathione (GSH).
The key role of GSH as an antioxidant is demonstrated by many studies showing that EXPERIMENTATAL DEPLETION OF GSH LEVELS – which can be achieved with various chemicals the most used of which is buthionine sulfoximine (BSO) an inhibitor of GSH synthesis – HAS A WORSENING EFFECT IN MANY DISEASE MODELS.
Conversely, REPLETING GSH LEVELS WITH PRECURSORS OF ITS SYNTHESIS HAS PROTECTIVE EFFECTS.
Cysteine precursors, rather than cysteine itself, are used because they are more cell-permeable, and can be given orally.
The most effective method of supplying Cysteine is thru GSH-I, a Primary whey. Please contact me for more info