As per the experts, oral dosage o f glutathione is 250mg twice daily empty stomach for up to 4 weeks, topical route is 2% (w/w) applied once daily for nearly 2 months, and intravenous route is 1200mg injection given weekly over 30 minutes
10.1016/S0891-5849(97)00280-3 61 DandonaP.GhanimH.BrooksD
[8] Administration of Glutathione: Pharmaceutical Formulations Glutathione is primarily available as oral formulations (pills, solutions, sublingual tablets, syrups and sprays) and parenteral formulations (intravenous and intramuscular)
The Antioxidant Role of Glutathione and N-Acetyl-Cysteine Supplements and Exercise-Induced Oxidative Stress.J Int Soc Sports Nutr .2005
In: Prasad MNV (ed) Abiotic Stress Responses in Plants: Metabolism, Productivity and Sustainability
Headaches have been reported, though distinguishing these from coincidental occurrences proves difficult