Glutathione (GSH) is a tripeptide thiol (γ-L-glutamyl-L-cysteinylglycine) that serves as the body's primary endogenous antioxidant and detoxifying agent. In the Indian pharmaceutical context, oral formulations of 600mg are widely marketed as dietary supplements and adjunctive therapy for various conditions related to oxidative stress, liver health, and skin lightening. Its clinical efficacy via oral route is debated due to significant first-pass metabolism, but it remains a popular OTC choice.
Adult: 600mg to 1200mg per day, divided into two or three doses (e.g., 600mg once or twice daily). Often taken on an empty stomach for better absorption, though evidence is mixed.
Note: Oral tablet/capsule. Should be taken with a full glass of water. For potential better absorption, it is often recommended to take on an empty stomach, 30 minutes before meals or 2 hours after meals. Avoid taking with high-protein meals simultaneously as it may compete for absorption.
Glutathione (GSH) is the most abundant intracellular non-protein thiol. It functions as a critical redox buffer, maintaining the reduced state of cellular components. It directly neutralizes reactive oxygen species (ROS) like hydrogen peroxide, hydroxyl radicals, and peroxynitrite via the glutathione peroxidase (GPx) reaction, where GSH is oxidized to glutathione disulfide (GSSG). GSSG is then reduced back to GSH by glutathione reductase (GR), using NADPH. It also conjugates with xenobiotics, toxins, and carcinogens (Phase II detoxification), forming mercapturates excreted in bile and urine. It regenerates other antioxidants like vitamins C and E.
Pregnancy: Category N (Not classified by US FDA). Insufficient data on use in pregnant women. Animal studies are not indicative of direct harm. Use only if potential benefit justifies potential risk to the fetus. Generally avoided.
Driving: No known effects on the ability to drive and use machines.
| Chemotherapy drugs (e.g., Cisplatin, Doxorubicin) | Theoretical: May reduce efficacy of certain chemotherapies that rely on oxidative stress for cytotoxicity. However, it may also protect against chemotherapy-induced toxicity. Evidence is conflicting and context-dependent. | Major - Requires medical supervision. |
| Acetaminophen (Paracetamol) | Glutathione is crucial in detoxifying N-acetyl-p-benzoquinone imine (NAPQI), the toxic metabolite of acetaminophen. Supplementation may support liver protection in overdose but does not replace N-acetylcysteine (NAC) as the antidote. | Moderate |
| Immunosuppressants (e.g., Cyclosporine, Tacrolimus) | Theoretical concern that by modulating lymphocyte function, it may alter immunosuppression. Clinical significance for oral doses is unknown. | Moderate |
Same composition (Glutathione (600mg)), different brands: