Based on this, anecdotal sources report a dose of 10-20mcg/kg, which would be equal to 1-2mg for a 200lb test subject
NutraBio Whey Protein Isolate chnh l s la chn s 1
Mechanism of Action Glutathione LPT harnesses advanced oral liposomal technology (LPT) to improve the absorption and delivery of S-acetyl L-glutathione at the cellular level
Pear (With Skin) The skin contains most of the fiber
And, if you WERE to support glutathione production with supplements, you may consider: lipoic acid, N-acetylcysteine (NAC), any polyphenol blend in low-moderate doses(since polyphenols all activate Nrf2, thus the Antioxidant Response Element on DNA, and ensuing transcription of several "antioxidants," including glutathione), singular polyphenols in low-end doses (think resveratrol, quercetin), and let's not forget simple Vit C