Glutathione Side Effects, Interactions and Safety
What research reports about glutathione side effects by form (oral, inhaled, injected), the asthma caution for inhaled glutathione, and where evidence on interactions is missing.
Content last updated . This page has not been medically reviewed.
If breathing becomes difficult, the face or throat swells, or a rash spreads after any glutathione product, get urgent help (in the US, call 911). Do not use inhaled glutathione from a nebulizer without a clinician's advice if you have asthma. [2]
Evidence labels used here: mixed, insufficient evidence, evidence of harm (in a small trial), and Proper evidence not found.
Safety by form
| Form | What the sources report | Label |
|---|---|---|
| Swallowed (oral) | In a 6-month placebo-controlled trial of 250 or 1,000 mg a day in 54 non-smoking adults, blood glutathione rose; the abstract we read does not report side-effect data. [3] A 2025 review describes oral use as having limited side effects. [4] A 2019 review of skin-color studies said some adverse events were reported but were not serious. [5] | Mixed: short trials; long-term safety not shown |
| Breathed in (nebulized) | A small crossover trial in eight people with mild asthma found nebulized glutathione caused major airway narrowing, with cough in four and breathlessness in three. [2] A 2008 review says bronchoconstriction has occurred among people with asthma presumed to be sulfite-sensitive, and that transient coughing and an unpleasant odor are common. [6] | Evidence of harm in asthma (small trial) |
| Injected (IV) | A small trial of IV glutathione three times a week for 4 weeks in 21 people with Parkinson's disease found it well tolerated. [7] Reviews of cosmetic use list anaphylaxis, liver toxicity, hypersensitivity and possible kidney and hormone effects. [4][8] | Mixed; see the injection page below |
The "asthma and glutathione" caution comes from the nebulized form. We did not find a source on whether glutathione swallowed as a supplement affects asthma. Proper evidence not found (PubMed search, October 2026).
Injections
Reviews describe no studies of long-term IV use for any purpose, and one concluded IV glutathione for skin lightening is contraindicated because of lack of efficacy and side effects. [1][9] Details are on Glutathione Injections, IV Drips and Skin-Lightening Claims.Medicine interactions
Proper evidence not found. We searched PubMed for glutathione supplement interactions with medicines and did not find or read a source describing them. That is not proof there are none. A pharmacist can check your medicines. Read Medication Interactions and ask before combining any supplement with medicines.Pregnancy, breastfeeding, children
Proper evidence not found for glutathione supplements in pregnancy, breastfeeding or children in the sources we read. See Pregnancy & Breastfeeding and Children & Teens, and talk to a clinician first.Kidney and liver conditions, and surgery
We did not find a source on oral glutathione in kidney or liver disease. Reviews of IV cosmetic use name liver toxicity and possible kidney effects, so anyone with these conditions should ask a clinician before any injection. [8] Tell the surgical team about every supplement before an operation: Supplements Before Surgery.Quality
Supplement contents can differ from the label. See Quality Testing and Certifications. For the differences between forms see Glutathione Supplements: Oral, Liposomal and What Evidence Supports.Frequently asked questions
Does glutathione cause side effects?
In short studies, oral glutathione is described as having limited, mostly non-serious side effects, while injections have been linked in reviews to anaphylaxis and liver toxicity. Long-term safety is not established. [4][5][1]
Is glutathione safe if I have asthma?
Nebulized (breathed-in) glutathione caused airway narrowing in a small trial of people with mild asthma. Ask your clinician before using it. [2]
Does glutathione interact with medicines?
We did not find a source we could read on this, so the answer is unknown. Ask a pharmacist. See Medication Interactions.
Is glutathione safe in pregnancy?
Proper evidence not found in the sources we read. Talk to a clinician before using it.
How much glutathione is safe?
No official safe amount or upper limit was found in sources we read. Study amounts are not advice; the 6-month oral trial used 250 or 1,000 mg a day in adults. [3]
References
- Davids LM, Van Wyk JC, Khumalo NP. Intravenous glutathione for skin lightening: Inadequate safety data. S Afr Med J, 2016 (PubMed abstract). Read 2026-10-23.
- Marrades RM, Roca J, Barbera JA, et al. Nebulized glutathione induces bronchoconstriction in patients with mild asthma. Am J Respir Crit Care Med, 1997 (PubMed abstract). Read 2026-10-23.
- Richie JP Jr, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr, 2015 (PubMed abstract). Read 2026-10-23.
- Alzahrani TF, Alotaibi SM, et al. Exploring the Safety and Efficacy of Glutathione Supplementation for Skin Lightening: A Narrative Review. Cureus, 2025 (PubMed abstract). Read 2026-10-23.
- Dilokthornsakul W, Dhippayom T, Dilokthornsakul P. The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. J Cosmet Dermatol, 2019 (PubMed abstract). Read 2026-10-23.
- Prousky J. The treatment of pulmonary diseases and respiratory-related conditions with inhaled (nebulized or aerosolized) glutathione. Evid Based Complement Alternat Med, 2008 (PubMed abstract). Read 2026-10-23.
- Hauser RA, Lyons KE, McClain T, et al. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord, 2009 (PubMed abstract). Read 2026-10-23.
- Aloraini K, Alangari A, Arif J, Alkhodairy F. Glutathione for skin lightening via intravenous, oral, and topical routes: a critical narrative review. J Med Life, 2026 (PubMed abstract). Read 2026-10-23.
- Sarkar R, Yadav V, Yadav T, et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol, 2025 (PubMed abstract). Read 2026-10-23.