Some hormone replacement preparations, certain biologics, and a number of compounded medications dispensed by private clinics arrive as powders for the same reason powdered formulations are far more stable in shipping and storage than ready-mixed solutions, and the user reconstitutes them at the point of use
It is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups to or from proteins, in posttranslational modifications
You can read more about the trial here: Setria glutathione has also been shown to have a unique stability against stomach acid, making it impressively bioavailable
Consider: daily multivitamin, vitamin D 2,000-4,000 IU daily (most people are deficient), vitamin B12 if energy is low, calcium 1,000-1,200mg daily (especially for women), fiber supplement if constipated, protein powder if struggling to hit 80-100g daily from food
Linkova, A