Glutathione Injection: Overview and Clinical Applications
Glutathione injection is not FDA-approved for general use and has limited evidence supporting its clinical efficacy, with potential safety concerns for chronic administration, particularly when used for cosmetic purposes such as skin lightening. 1
What is Glutathione?
Glutathione (GSH) is a tripeptide composed of gamma-glutamyl-cysteinyl-glycine that serves as the most abundant naturally occurring non-protein thiol in mammalian cells. It functions as a critical antioxidant with several important physiological roles:
- Protection against oxidative stress and free radicals
- Detoxification of xenobiotics and heavy metals
- Maintenance of cellular redox balance
- Support of immune function
- Regulation of cellular processes including proliferation and apoptosis 2, 3
In the body, glutathione exists in two forms:
- Reduced form (GSH) - the active antioxidant form
- Oxidized form (GSSG) - formed when two GSH molecules combine via disulfide bonds 4
Medical Applications of Glutathione
Critical Illness and Parenteral Nutrition
The European Society for Clinical Nutrition and Metabolism (ESPEN) recommends glutamine supplementation (not glutathione) at 0.2-0.4 g/kg/day when parenteral nutrition is indicated in critically ill patients. This has been shown to reduce mortality risk and infectious complications 5. However, glutathione itself is not recommended for this purpose.
Chemotherapy-Induced Neuropathy
Small randomized trials have evaluated glutathione's protective effects against platinum-based chemotherapy-induced peripheral neuropathy. Five of six small trials reported statistically significant reduction in neurotoxicity with glutathione administration compared to placebo. However, a larger placebo-controlled trial found no benefit of glutathione for preventing neurotoxicity in patients receiving paclitaxel/carboplatin therapy 6.
Cystic Fibrosis
According to ESPEN-ESPGHAN-ECFS guidelines, there are no data supporting the use of glutathione therapy in cystic fibrosis patients 6.
Ophthalmic Use
The only FDA-approved glutathione product is BSS PLUS®, which contains oxidized glutathione as part of a sterile intraocular irrigating solution used during ophthalmic surgical procedures. This solution is specifically labeled "NOT FOR INJECTION OR INTRAVENOUS INFUSION" 7.
Safety Concerns
Despite widespread reported use, particularly for cosmetic purposes:
- There are no studies of intravenous glutathione use for skin lightening or its safety for chronic administration 1
- The switch from brown to red melanin production with glutathione may increase the risk of sun-induced skin cancers in previously protected individuals 1
- Intravenous administration carries inherent risks including infection, vein irritation, and potential allergic reactions
- Regulatory assessment of systemic glutathione administration for cosmetic use appears warranted to protect consumers 1
Oral Supplementation
While intravenous glutathione has limited evidence, oral glutathione supplementation has shown some promise:
- A 6-month randomized, double-blind, placebo-controlled trial found that daily consumption of oral glutathione supplements (250 or 1,000 mg/day) effectively increased body stores of glutathione in healthy adults 8
- At 6 months, mean glutathione levels increased 30-35% in erythrocytes, plasma, and lymphocytes in the high-dose group
- These increases were dose and time-dependent, with levels returning to baseline after a 1-month washout period 8
Conclusion
Glutathione injection is not FDA-approved for general medical use outside of specific ophthalmic applications. While glutathione plays important physiological roles as an antioxidant, current evidence does not support its intravenous administration for most clinical conditions. The use of intravenous glutathione for cosmetic purposes such as skin lightening lacks safety data and may pose significant risks. Patients seeking antioxidant support may consider oral glutathione supplementation, which has demonstrated the ability to increase body stores of glutathione with fewer safety concerns.