Glutathione
Glutathione is an endogenous intracellular antioxidant, but route and outcome determine what supplementation can do. Oral supplementation can change glutathione biomarkers; inhaled and intravenous trials have not shown broad clinical benefit, and recent FDA alerts document serious endotoxin-related harm from compounded injections.
endogenous tripeptide
- Reduced glutathione is gamma-Glu-Cys-Gly
- Endogenous redox tripeptide
- Oral biomarker effects do not establish IV wellness benefit
- No FDA-approved injectable skin-lightening indication
What exactly is glutathione?
Reduced glutathione is the endogenous tripeptide gamma-glutamyl-cysteinyl-glycine. Oral, inhaled, intranasal, topical, and intravenous products create different exposure and cannot share one efficacy or safety conclusion.
Oral RCT · body-store biomarkers
Randomized double-blind placebo-controlled trial
Richie JP Jr et al. European Journal of Nutrition, 2015.
Fifty-four nonsmoking adults received 250 mg, 1,000 mg, or placebo daily for six months. Glutathione rose in several measured body compartments, then returned toward baseline after washout. The study measured antioxidant and immune biomarkers, not a general health or longevity outcome.
- Participants / model
- 54 healthy nonsmoking adults
- Treatment
- Oral reduced glutathione 250 mg, 1,000 mg, or placebo daily
- Follow-up
- 6 months plus washout
- Study design
- Randomized double-blind placebo-controlled trial
Biomarker change does not establish disease prevention or a felt wellness benefit.
Read the original sourceCF RCT · primary lung outcome negative
Randomized placebo-controlled trial
Griese M et al. American Journal of Respiratory and Critical Care Medicine, 2013.
In 153 people with cystic fibrosis, six months of inhaled glutathione did not significantly improve the primary FEV1 outcomes, exacerbations, or quality of life despite targeting airway redox biology.
- Participants / model
- 153 people with cystic fibrosis
- Treatment
- Inhaled glutathione or placebo
- Follow-up
- 6 months
- Study design
- Randomized double-blind placebo-controlled trial
Does supplementation improve health outcomes?
Oral glutathione can increase measured glutathione stores, but the trial did not establish broader health benefits. Controlled inhaled, intranasal, and IV trials in specific diseases were negative on their main clinical comparisons.
| Route | Population | Finding |
|---|---|---|
| Oral | 54 healthy adults | Glutathione biomarkers increased |
| Inhaled | 153 people with cystic fibrosis | No significant primary FEV1 benefit |
| Intravenous | 21 people with Parkinson disease | No significant UPDRS benefit |
| Intranasal | Parkinson disease phase IIb | No superiority at 3 months |
Oral RCT · body-store biomarkers
Randomized double-blind placebo-controlled trial
Richie JP Jr et al. European Journal of Nutrition, 2015.
Fifty-four nonsmoking adults received 250 mg, 1,000 mg, or placebo daily for six months. Glutathione rose in several measured body compartments, then returned toward baseline after washout. The study measured antioxidant and immune biomarkers, not a general health or longevity outcome.
- Participants / model
- 54 healthy nonsmoking adults
- Treatment
- Oral reduced glutathione 250 mg, 1,000 mg, or placebo daily
- Follow-up
- 6 months plus washout
- Study design
- Randomized double-blind placebo-controlled trial
Biomarker change does not establish disease prevention or a felt wellness benefit.
Read the original sourceCF RCT · primary lung outcome negative
Randomized placebo-controlled trial
Griese M et al. American Journal of Respiratory and Critical Care Medicine, 2013.
In 153 people with cystic fibrosis, six months of inhaled glutathione did not significantly improve the primary FEV1 outcomes, exacerbations, or quality of life despite targeting airway redox biology.
- Participants / model
- 153 people with cystic fibrosis
- Treatment
- Inhaled glutathione or placebo
- Follow-up
- 6 months
- Study design
- Randomized double-blind placebo-controlled trial
One-year CF trial · prespecified target missed
Randomized controlled trial
Visca A et al. Journal of Cystic Fibrosis, 2015.
The 105-person study did not meet its prespecified 15% FEV1-improvement objective. Subgroup and transient signals did not convert the overall trial into a positive primary result.
- Participants / model
- 105 people with cystic fibrosis
- Treatment
- Inhaled glutathione or control
- Follow-up
- 12 months
- Study design
- Randomized controlled trial
IV pilot · no significant UPDRS benefit
Randomized double-blind pilot trial
Hauser RA et al. Movement Disorders, 2009.
Twenty-one people with Parkinson disease were randomized to IV glutathione or placebo. The between-group UPDRS difference was 2.8 points with P=.32, and the washout comparison was also not significant. The pilot did not establish clinical benefit.
- Participants / model
- 21 people with Parkinson disease
- Treatment
- Intravenous glutathione or placebo
- Study design
- Randomized double-blind pilot trial
Intranasal RCT · no superiority at 3 months
Randomized placebo-controlled trial
Mischley LK et al. Movement Disorders, 2017.
Intranasal glutathione did not outperform placebo on the principal three-month clinical comparison. The trial does not support transferring a biomarker rationale into a proven neurological benefit.
- Participants / model
- People with Parkinson disease
- Treatment
- Intranasal glutathione at two doses or placebo
- Follow-up
- 3 months
- Study design
- Randomized double-blind placebo-controlled phase IIb trial
Does antioxidant biology predict clinical benefit?
Glutathione is central to intracellular redox control, but supplement route, cellular uptake, metabolism, compartment, baseline status, and disease state determine whether an intervention changes a clinical outcome. Essential biology alone cannot answer that.
Oral RCT · body-store biomarkers
Randomized double-blind placebo-controlled trial
Richie JP Jr et al. European Journal of Nutrition, 2015.
Fifty-four nonsmoking adults received 250 mg, 1,000 mg, or placebo daily for six months. Glutathione rose in several measured body compartments, then returned toward baseline after washout. The study measured antioxidant and immune biomarkers, not a general health or longevity outcome.
- Participants / model
- 54 healthy nonsmoking adults
- Treatment
- Oral reduced glutathione 250 mg, 1,000 mg, or placebo daily
- Follow-up
- 6 months plus washout
- Study design
- Randomized double-blind placebo-controlled trial
Biomarker change does not establish disease prevention or a felt wellness benefit.
Read the original sourceCF RCT · primary lung outcome negative
Randomized placebo-controlled trial
Griese M et al. American Journal of Respiratory and Critical Care Medicine, 2013.
In 153 people with cystic fibrosis, six months of inhaled glutathione did not significantly improve the primary FEV1 outcomes, exacerbations, or quality of life despite targeting airway redox biology.
- Participants / model
- 153 people with cystic fibrosis
- Treatment
- Inhaled glutathione or placebo
- Follow-up
- 6 months
- Study design
- Randomized double-blind placebo-controlled trial
Does glutathione lighten skin?
Small oral and topical studies report changes in melanin measures, but effects are modest, designs often bundle routes or ingredients, and none validates IV skin lightening. Durable benefit and long-term safety remain uncertain.
Skin study · routes bundled
Randomized split-face human study
Wahab S et al. Clinical, Cosmetic and Investigational Dermatology, 2021.
Forty-six participants used oral glutathione while topical glutathione and placebo were compared across facial sides. The bundled design cannot isolate the oral effect from the topical effect or establish injectable skin lightening.
- Participants / model
- 46 adults in a cosmetic pigmentation study
- Treatment
- Oral glutathione plus side-specific topical glutathione or placebo
- Study design
- Small randomized split-face combination study
The route-specific contribution is not isolated.
Read the original sourceWhat are the main safety concerns?
Route matters. Oral and topical tolerability cannot establish injection safety. FDA’s August 2026 investigation links at least 30 adverse-event reports to IV products made from one unsuitable ingredient lot, and a separate patient-level recall involved elevated endotoxin.
The documented cluster involved product quality and endotoxin contamination. It does not estimate the intrinsic adverse-event rate of uncontaminated glutathione.
FDA 2026 · at least 30 adverse-event reports
FDA safety communication
US Food and Drug Administration, 27 August 2026.
FDA reported at least 30 patients with adverse events after IV glutathione alone or in combinations made by different pharmacies using one dietary-supplement-grade ingredient lot. Reported events included fever, chills, pain, dizziness, shock-like and sepsis-like symptoms, with some hospitalizations; FDA said the pattern was consistent with excessive endotoxin.
- Participants / model
- At least 30 reported patients linked to products made from one ingredient lot
- Treatment
- Compounded IV glutathione alone or in combinations
- Study design
- Ongoing regulator adverse-event and supply-chain investigation
The events document a contaminated-ingredient and sterile-compounding hazard; they do not estimate intrinsic glutathione toxicity.
Read the original sourceFDA-posted recall · one 2026 lot
FDA-posted company recall
Optimal Balance Pharmacy, announced 19 August 2026; FDA posted 20 August 2026.
One lot of compounded glutathione 200 mg/mL multidose vials was recalled after elevated bacterial endotoxin was identified. Reported events included fever, chills, severe headache, nausea, vomiting, pain, and allergy-like symptoms.
- Study design
- Patient-level recall of a specified lot
FDA posts company announcements as a public service and does not endorse the product or announcement.
Read the original sourceIs injectable glutathione approved for skin lightening or wellness?
The cited FDA records list no approved injectable glutathione indication for skin lightening or wellness. Category 1 under the 503A nomination process means evaluation is pending, not approval.
FDA 503A · glutathione under evaluation
FDA regulatory document
US Food and Drug Administration, updated 14 May 2026.
Glutathione appears in Category 1 as a nominated bulk substance under evaluation for 503A compounding. This is not an approved-drug finding or evidence for skin lightening or wellness use.
- Study design
- Current compounding-nomination status document
FDA 2026 · at least 30 adverse-event reports
FDA safety communication
US Food and Drug Administration, 27 August 2026.
FDA reported at least 30 patients with adverse events after IV glutathione alone or in combinations made by different pharmacies using one dietary-supplement-grade ingredient lot. Reported events included fever, chills, pain, dizziness, shock-like and sepsis-like symptoms, with some hospitalizations; FDA said the pattern was consistent with excessive endotoxin.
- Participants / model
- At least 30 reported patients linked to products made from one ingredient lot
- Treatment
- Compounded IV glutathione alone or in combinations
- Study design
- Ongoing regulator adverse-event and supply-chain investigation
The events document a contaminated-ingredient and sterile-compounding hazard; they do not estimate intrinsic glutathione toxicity.
Read the original sourceStudies and sources
Oral RCT · body-store biomarkers
Randomized double-blind placebo-controlled trial
Richie JP Jr et al. European Journal of Nutrition, 2015.
Fifty-four nonsmoking adults received 250 mg, 1,000 mg, or placebo daily for six months. Glutathione rose in several measured body compartments, then returned toward baseline after washout. The study measured antioxidant and immune biomarkers, not a general health or longevity outcome.
- Participants / model
- 54 healthy nonsmoking adults
- Treatment
- Oral reduced glutathione 250 mg, 1,000 mg, or placebo daily
- Follow-up
- 6 months plus washout
- Study design
- Randomized double-blind placebo-controlled trial
Biomarker change does not establish disease prevention or a felt wellness benefit.
Read the original sourceCF RCT · primary lung outcome negative
Randomized placebo-controlled trial
Griese M et al. American Journal of Respiratory and Critical Care Medicine, 2013.
In 153 people with cystic fibrosis, six months of inhaled glutathione did not significantly improve the primary FEV1 outcomes, exacerbations, or quality of life despite targeting airway redox biology.
- Participants / model
- 153 people with cystic fibrosis
- Treatment
- Inhaled glutathione or placebo
- Follow-up
- 6 months
- Study design
- Randomized double-blind placebo-controlled trial
One-year CF trial · prespecified target missed
Randomized controlled trial
Visca A et al. Journal of Cystic Fibrosis, 2015.
The 105-person study did not meet its prespecified 15% FEV1-improvement objective. Subgroup and transient signals did not convert the overall trial into a positive primary result.
- Participants / model
- 105 people with cystic fibrosis
- Treatment
- Inhaled glutathione or control
- Follow-up
- 12 months
- Study design
- Randomized controlled trial
IV pilot · no significant UPDRS benefit
Randomized double-blind pilot trial
Hauser RA et al. Movement Disorders, 2009.
Twenty-one people with Parkinson disease were randomized to IV glutathione or placebo. The between-group UPDRS difference was 2.8 points with P=.32, and the washout comparison was also not significant. The pilot did not establish clinical benefit.
- Participants / model
- 21 people with Parkinson disease
- Treatment
- Intravenous glutathione or placebo
- Study design
- Randomized double-blind pilot trial
Intranasal RCT · no superiority at 3 months
Randomized placebo-controlled trial
Mischley LK et al. Movement Disorders, 2017.
Intranasal glutathione did not outperform placebo on the principal three-month clinical comparison. The trial does not support transferring a biomarker rationale into a proven neurological benefit.
- Participants / model
- People with Parkinson disease
- Treatment
- Intranasal glutathione at two doses or placebo
- Follow-up
- 3 months
- Study design
- Randomized double-blind placebo-controlled phase IIb trial
Skin study · routes bundled
Randomized split-face human study
Wahab S et al. Clinical, Cosmetic and Investigational Dermatology, 2021.
Forty-six participants used oral glutathione while topical glutathione and placebo were compared across facial sides. The bundled design cannot isolate the oral effect from the topical effect or establish injectable skin lightening.
- Participants / model
- 46 adults in a cosmetic pigmentation study
- Treatment
- Oral glutathione plus side-specific topical glutathione or placebo
- Study design
- Small randomized split-face combination study
The route-specific contribution is not isolated.
Read the original sourceFDA 2026 · at least 30 adverse-event reports
FDA safety communication
US Food and Drug Administration, 27 August 2026.
FDA reported at least 30 patients with adverse events after IV glutathione alone or in combinations made by different pharmacies using one dietary-supplement-grade ingredient lot. Reported events included fever, chills, pain, dizziness, shock-like and sepsis-like symptoms, with some hospitalizations; FDA said the pattern was consistent with excessive endotoxin.
- Participants / model
- At least 30 reported patients linked to products made from one ingredient lot
- Treatment
- Compounded IV glutathione alone or in combinations
- Study design
- Ongoing regulator adverse-event and supply-chain investigation
The events document a contaminated-ingredient and sterile-compounding hazard; they do not estimate intrinsic glutathione toxicity.
Read the original sourceFDA-posted recall · one 2026 lot
FDA-posted company recall
Optimal Balance Pharmacy, announced 19 August 2026; FDA posted 20 August 2026.
One lot of compounded glutathione 200 mg/mL multidose vials was recalled after elevated bacterial endotoxin was identified. Reported events included fever, chills, severe headache, nausea, vomiting, pain, and allergy-like symptoms.
- Study design
- Patient-level recall of a specified lot
FDA posts company announcements as a public service and does not endorse the product or announcement.
Read the original sourceFDA 503A · glutathione under evaluation
FDA regulatory document
US Food and Drug Administration, updated 14 May 2026.
Glutathione appears in Category 1 as a nominated bulk substance under evaluation for 503A compounding. This is not an approved-drug finding or evidence for skin lightening or wellness use.
- Study design
- Current compounding-nomination status document
Why is Glutathione in D tier?
D reflects route-specific evidence. Oral supplementation can increase glutathione biomarkers, while broad clinical and intravenous cosmetic benefits remain unsupported. Glutathione's endogenous redox role is established.