Antioxidant

Glutathione (Reduced Form)

Also known as: L-glutathione, GSH, reduced glutathione, gamma-glutamylcysteinylglycine

Evidence

Reduced glutathione is a tripeptide antioxidant produced endogenously that plays a critical role in cellular detoxification and redox balance. Oral bioavailability is very limited due to degradation in the gastrointestinal tract, making supplementation efficacy questionable for systemic glutathione status.

Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.

Find the best Glutathione (Reduced Form) supplements — free

See Glutathione (Reduced Form) products scored on dose & form, then track your intake in the app.

Open app →

Primary uses

Antioxidant support
Cellular detoxification
Immune function support
Oxidative stress reduction

How it works

Acts as a direct free radical scavenger and reduces oxidative stress
Cofactor for glutathione peroxidase and glutathione S-transferase enzymes
Supports cellular redox homeostasis
May enhance detoxification pathways

Dosage

Typical range: 250-1500 mg daily
Timing: Morning on empty stomach may improve absorption slightly
With food: With food may reduce absorption; optimal timing unclear due to low bioavailability
Duration: Ongoing use is typical for those seeking antioxidant support; no established maximum duration
Special populations: Pregnant/nursing women should consult healthcare provider; those with severe liver disease should use cautiously

Forms

Powder· 70/100
Capsule· 70/100
Liposomal· 70/100
Sublingual· 70/100

Safety

Common side effects

Generally well-tolerated at typical doses
Mild nausea or abdominal discomfort (rare)
Headache (rare)

Contraindications

High doses may theoretically interact with chemotherapy or radiation therapy
Caution in individuals with cystinuria

Products containing Glutathione (Reduced Form)

Top-scoring supplements in our catalog that list Glutathione (Reduced Form) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.

MediClear-SGS™ - Vanilla

Thorne

Daily Greens Plus

See all products →

Evidence notes

While glutathione's biological role is well-established, oral supplementation has limited evidence for systemic bioavailability and clinical efficacy. Most studies using glutathione were IV or inhaled; oral studies show minimal absorption. Grade C reflects preliminary evidence for oral form specifically.

Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.

Related in Antioxidant

Check a full stack

Formulate's free interaction checker lets you paste in any combination of supplements and medications at once — every pairing flags severity, timing, and cited evidence.

Open the checker

Where does Glutathione (Reduced Form) fit in your stack?

Answer two questions and get a stack graded on research — every ingredient scored on the evidence behind it, not the marketing.

Build my stack

2 questions · free · no account needed to start

Also on iPhone — get the free app

📬 Get new guides in your inbox

Evidence-based supplement guides, no spam

We send a short digest when new guides drop — nothing else. No affiliate pushes, no sponsored content, unsubscribe anytime.

Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.