Glutathione side effects and risks

Reported side effects

• Injection pain, itching or lumps: Reported in forums; no reliable incidence estimate., mild. Persistent, worsening or spreading symptoms need assessment. (source)
• Stomach cramps or diarrhea with IV mixture: One nonrandomized IV study: cramps 10/25; diarrhea 4/25; none reported in controls., moderate (source)
• Itching during oral dosing: Reduced GSH 2/20; oxidized GSSG 1/18; placebo 2/19 completers., mild (source)
• Abnormal liver tests: IV mixture study 8/25; oral study had two transient cases with allocation unstated., serious. Stop and investigate new jaundice or marked liver-test changes. (source)
• Severe allergic reaction: One anaphylactic shock in 25 recipients of an IV mixture; general incidence unknown., serious. Stop infusion and seek emergency care. (source)
• Endotoxin-related infusion illness: FDA reported at least 30 affected patients in August 2026; denominator unknown., serious. Fever, shaking, fainting or breathing trouble after an infusion need urgent care. (source)
• Airway narrowing with inhalation: Asthma challenge: FEV1 −19% vs −1% saline; cough 4/8, breathlessness 3/8., serious (source)
• Severe blistering skin reaction: SJS/TEN case after an IV mixture containing glutathione and vitamins C and D., serious (source)
• Cardiomyopathy in nasal trial: One participant in the high dose phase 2b group; causation uncertain., serious (source)

Stop and get help if

• Trouble breathing, throat swelling, fainting or collapse after an injection: Stop the infusion and get emergency care now.
• Fever, severe chills, shaking, chest pain or confusion after an infusion: Seek emergency assessment for contamination, shock or infection.
• Painful spreading rash, blisters, peeling skin or sores in the mouth or eyes: Stop exposure and seek emergency care now.
• Yellow eyes or skin, dark urine or severe new upper abdominal pain: Stop use and obtain urgent liver assessment.

Who should avoid it

• pregnant: No established safety for systemic supplement or cosmetic injection protocols in pregnancy.
• breastfeeding: Milk transfer and infant safety are unknown; breastfeeding was excluded from the IV skin study.
• tryingToConceive: Reproductive safety is not established.
• under18: Pediatric disease trials do not establish safety for cosmetic or wellness use.
• other: Anaphylaxis has occurred with injected mixtures. Avoid repeat exposure to a suspected culprit.
• other: Nebulized glutathione caused major airway narrowing in people with asthma. This screen applies to inhalation.
• kidneyDisease: Kidney disease changes clinical risk and fluid tolerance. Dialysis trials do not establish an unsupervised dose.
• liverDisease: Benefits in liver disease are unproven, and IV mixtures have caused abnormal liver tests.
• heartCondition: Fluid infusions need review. One nasal-trial participant developed cardiomyopathy; causation was uncertain.
• activeCancer: Review with the oncology team. Chemotherapy interactions and benefits depend on the exact regimen.
• diabetes: A small trial improved insulin sensitivity. The effect on low-blood-sugar risk with medicines is unknown.
• testedAthlete: The substance is not named as prohibited, but IV volumes above 100 mL per 12 hours can breach WADA M2.2.

Interactions

• Cancer chemotherapy: Small platinum trials and the negative N08CA trial differ. Tumor protection or altered drug effects cannot be ruled out for other regimens.
• Insulin and sulfonylureas: Possible added glucose lowering is a precaution from insulin-sensitivity data; a clinical interaction has not been established.
• Tirzepatide with poor food intake and IV mixtures: One shock case involved tirzepatide and prolonged low food intake. It does not prove a drug interaction.
• Vitamin C, NAC and antioxidant mixtures: Oral mixtures have been studied, but extra benefit is uncertain. Injectable mixtures add ingredients and complicate reaction assessment.

Product quality risks

• FDA found excessive endotoxin in raw glutathione used for injections in 2019, with some samples up to five times the appropriate limit.
• In August 2026, FDA reported at least 30 patients with reactions after compounded IV glutathione alone or in mixtures.
• A raw-material COA did not prevent the 2019 incident. Supplement-grade material is unsuitable for sterile injections.
• No representative survey of online glutathione vial identity or dose accuracy was found. Counterfeit-pen rates from other drugs do not apply.