Wellness and performance
Skin & aging
Glutathione
Also called GSH
Glutathione is a major antioxidant peptide inside cells. Learn how it works, what small human trials show, and why it is not FDA-approved as a drug.
- Reviewed by
- William Maish, MD MBA MPH, Clinical Product Lead
- Published
- October 5, 2026
- Last updated
- October 5, 2026
Key takeaway
Glutathione is a major antioxidant tripeptide inside the body's cells, sold as a supplement and, in wellness clinics, as an IV, injectable, or inhaled product for skin-lightening and general antioxidant support. Human trials are small and mixed. In a 6-month randomized trial of 153 people with cystic fibrosis, inhaled glutathione did not improve lung function (FEV1) over placebo (p = 0.180). The FDA has warned about compounded injectable glutathione, and as of 2026 glutathione is not FDA-approved as a drug.
At a glance
| FDA status | Not FDA-approved as a drug; oral forms are sold as supplements and IV/inhaled forms are compounded |
| What it is | Naturally occurring antioxidant tripeptide |
| Research | Small human trials for skin-lightening and neurological uses show modest, mixed results |
| Safety | The FDA has warned about compounded injectable glutathione over safety concerns |
| Evidence strength | Moderate research |
What is glutathione?
Glutathione is a naturally occurring three-amino acid peptide (often abbreviated GSH) that serves as a major antioxidant inside cells. It is sold as an oral dietary supplement and, in wellness settings, as an intravenous, injectable, or inhaled product, promoted for skin-lightening and general antioxidant and wellness support. As a drug it is not FDA-approved.
How does it work?
Glutathione's biochemical role as a major intracellular antioxidant and detoxifier is well established; it neutralizes reactive molecules through enzyme systems. For skin-lightening, the proposed mechanism is inhibition of the pigment enzyme tyrosinase and a shift in pigment production toward lighter melanin. This describes the mechanism; the human evidence below tests whether supplementation produces the marketed effects.
Is it FDA-approved?
No, not as a drug. Oral glutathione is sold as a dietary supplement, and IV, injectable, and inhaled forms are compounded rather than FDA-approved. The FDA has issued a safety alert warning against using dietary-ingredient glutathione powder to compound sterile injectables, citing adverse events and contamination concerns. Compounded IV and inhaled glutathione therefore carry specific FDA safety warnings.
On the FDA's May 14, 2026 list of 503A bulk drug substances, glutathione sits in category 1, under evaluation1.
What does the research show?
There are several small human trials, with modest and mixed results. The skin results below are as reported on PubMed:
| Study | Area | Result |
| 4-week trial2 of oral glutathione | Skin | Small reductions in skin pigment versus placebo |
| 12-week trial3 of an oral combination | Skin | Reported skin lightening |
| Systematic review4 | Skin | Skin-whitening evidence is inconclusive due to study quality and bioavailability concerns |
| Randomized pilot5 of IV glutathione | Parkinson's disease | No significant benefit over placebo |
| Meta-analysis6 | Parkinson's disease | Only a small motor-score improvement |
| 6-month trial of oral glutathione in 54 non-smoking adults7 | Glutathione levels | Red blood cell, plasma, and lymphocyte glutathione rose 30% to 35%7 at the higher amount; levels returned to baseline after a 1-month washout |
| 6-month randomized trial of inhaled glutathione in 153 people with cystic fibrosis8 | Lung function | FEV1 did not differ from placebo (p = 0.180), and oxidation markers did not change |
Overall the human evidence is real but modest, short-term, and inconsistent.
More for skin & aging
Sources: oral glutathione skin trials (Arjinpathana and Asawanonda, Journal of Dermatological Treatment, 2012, DOI: 10.3109/095466310038016192; Journal of Cosmetic Dermatology, 2021, DOI: 10.1111/jocd.141373); a systematic review (Journal of Cosmetic Dermatology, 2019, DOI: 10.1111/jocd.129104); and Parkinson's trials (Movement Disorders, 2009, DOI: 10.1002/mds.224015; Experimental and Therapeutic Medicine, 2020, DOI: 10.3892/etm.2020.95576), all indexed on PubMed; and an FDA safety alert on compounded glutathione injectables. This document is educational, is not medical advice or a health claim, and is not an offer to sell any product.