Limited human dataFDA 503A Category 1

Glutathione side effects

Also known as: GSH · L-glutathione · Reduced glutathione · L-glutathione reduced · Gluta · Glutathione peptide · gamma-Glu-Cys-Gly

Updated Oct 24, 202656 sources

10 side effects reported for Glutathione: 5 from studies and labels, 5 from users and guides. 10 come with the ways people manage them.

Glutathione overview

Side effects reported in studies and labels

Rates as each trial or label states them. A rate from one trial does not carry over to research-grade vials or other doses.

From trials and regulators5

Clinical studies and regulatory documents.

Abnormal liver tests with IV glutathione
FDA's 2022 review counted 8 cases of deranged liver tests across 5 IV studies, plus one FAERS report of liver injury on 1,200 mg once a week
How people manage it
- In the FAERS case, liver injury resolved within 2 months of stopping the medicines
- New fatigue, dark urine or yellowing skin after IV doses needs a doctor and blood tests
Allergic and infusion reactions, including anaphylaxis
FAERS 2000 to 2021: 2 anaphylaxis, 7 infusion-reaction and 3 hypersensitivity reports with IV glutathione
How people manage it
- Facial or throat swelling, wheeze or collapse is an emergency
Fever, chills and vomiting from contaminated powder
Seven clinic patients reacted within minutes of one compounded IV batch in 2019; one went to hospital
How people manage it
- FDA traced it to endotoxin in powder labelled as a dietary supplement; injectable product should be made from ingredients meant for sterile use
Bronchospasm when inhaled
Nebulized 600 mg cut FEV1 by 19% in 8 people with mild asthma; 4 coughed and 3 got breathless
How people manage it
- Do not nebulize glutathione with asthma or reactive airways
- Any wheeze or chest tightness after a dose is a stop signal
Cardiomyopathy (single case, intranasal)
One participant on the high intranasal dose in a 45-person trial
How people manage it
- FDA's review notes it resolved when glutathione was stopped

Side effects users and guides report

What people post and what dosing guides list. These are reports, not measured rates.

From users and guides5

Community reports, competitor and vendor guides, media.

Sting or burn during the injection
Commonly reported on r/Peptides; one poster says it burns more than anything else they inject
How people manage it
- Inject very slowly; posters say speed matters more than needle size
- Let the dose warm to room temperature after the fridge
- Try IM in a delt or glute, which a guide says usually stings less than subQ
- Split a 1 mL dose across two sites
Lumps, knots or welts at subQ sites
Commonly reported on r/Peptides; some say lumps last 2 to 3 days, a few say weeks
How people manage it
- Switch to IM; several posters say the welts stopped
- Use less water so each dose is a smaller volume
- Rotate sites; see a clinician for a hot, growing or painful lump
Soreness after IM shots
Reported on r/Peptides, mostly with thigh injections
How people manage it
- Posters prefer the delt or ventrogluteal site over the thigh
- Start with a smaller volume
Sulfur or metallic taste or smell
Commonly reported by guides shortly after a dose; never formally measured
How people manage it
- Harmless on its own; liposomal oral products are said to mask the taste better
Bloating, gas or loose stools with oral glutathione
Mild and occasional in oral trials and guides
How people manage it
- Take with a little food, though guides note empty-stomach dosing is the usual convention
- Lower the dose

Who should avoid it, and what not to combine

Asthma or reactive airway disease (inhaled glutathione)Condition
Nebulized glutathione caused clear bronchoconstriction in people with mild asthma, likely from sulfite formation.
Supplement-grade or non-sterile glutathione powder for injectionSubstance
FDA linked 2019 IV reactions to endotoxin in powder labelled for dietary supplement use, which should never have gone into a sterile injectable.
Platinum chemotherapy without the oncologist's approvalSubstance
In one 27-patient study cited by FDA, the glutathione group had lower levels of the chemo drug, which could affect how well it works.
Pregnancy or breastfeedingCondition
No safety data for injected glutathione in pregnancy or lactation.

How much is known

Limited human data

Plenty of small human trials, few solid answers. Oral glutathione raised blood levels over 6 months in one RCT but did nothing in another 4-week RCT. Oral and IV trials show modest skin lightening that fades after stopping. IV and nasal trials in Parkinson's did not beat placebo. No trial has tested subQ glutathione or the 100 to 200 mg home doses. FDA's 2022 review found effectiveness unsupported for all 24 uses it checked.