https://pmc.ncbi.nlm.nih.gov/articles/PMC10075255/ (2023)
The main routes of administration of glutathione are oral, intramuscular, and intravenous. Intravenous GSH has a short half-life but has shown to be effective in several diseases. For example, the GSH intravenous administration in patients with Parkinson’s disease determined significant improvements, which lasted for 2–4 months after the administration (26). Also oral administration, although with conflicting results, resulted in increased serum GSH levels with reduced oxidative stress and beneficial effects in several diseases (27, 28).
Richie et al. recently found that oral GSH at either 250 or 1,000 mg/day was associated to significant increase in the body storage of GSH in non-smoking adults, in a dose-dependent manner (27). They also noticed a decrease in the markers of oxidative stress at 6 months, as shown by the improvement in the GSSG/GSH ratio.
Furthermore, recent studies suggested that GSH oral administration in
liposomal or sublingual forms may have a better bioavailability, with a favorable impact on systemic GSH levels (29, 30). For example, a novel GSH formulation bypassing the gastrointestinal digestion through an oral absorption, gave positive results in raising GSH blood concentration in vitro and in vivo (31). Moreover, this molecule showed a promising hepatoprotective function in a murine model of acute liver injury (32).