Longevity · Tripeptide antioxidant · Compounded 503A
Glutathione: the master intracellular antioxidant.
Glutathione (GSH) is a tripeptide of glutamate, cysteine, and glycine present in every cell. It is the body's principal intracellular antioxidant and the obligatory cofactor for Phase II liver detoxification. Tissue levels fall meaningfully with age, oxidative stress, and chronic illness — and restoring them is one of the most established interventions in functional medicine.
What Glutathione is
Glutathione is a tripeptide (γ-glutamyl-cysteinyl-glycine) and the most abundant intracellular antioxidant in the human body. Its bioactivity comes from the thiol (-SH) group on its central cysteine residue.
It exists in two interchangeable forms: reduced (GSH, the active form) and oxidized (GSSG). The GSH:GSSG ratio is one of the canonical biomarkers of cellular redox status.
Tissue glutathione falls with age, smoking, alcohol, acetaminophen exposure, chronic infection, and severe illness. Restoring it has documented benefits in liver disease, Parkinson's, COPD, and oxidative-stress conditions.
How it works
GSH neutralizes reactive oxygen species (hydrogen peroxide, lipid peroxides, hydroxyl radical) by donating an electron from its cysteine thiol — becoming GSSG in the process. The enzyme glutathione reductase recycles GSSG back to GSH using NADPH.
It is the obligatory cofactor for glutathione-S-transferases — the Phase II liver enzymes that conjugate fat-soluble toxins (drugs, environmental chemicals, hormone metabolites) into water-soluble forms for biliary and renal excretion.
It also regenerates oxidized vitamins C and E, modulates immune-cell redox signaling, and supports mitochondrial membrane integrity by protecting cardiolipin from peroxidation.
What patients use it for
Antioxidant defense
Neutralizes reactive oxygen species across the cytoplasm and mitochondria — the body's first-line cellular antioxidant.
Phase II detoxification
Obligatory cofactor for glutathione-S-transferases — clears drug metabolites, environmental toxins, and reactive hormone metabolites.
Skin clarity
Inhibits tyrosinase (the rate-limiting enzyme in melanin synthesis) — the basis for its dermatology use for hyperpigmentation and melasma.
Mitochondrial protection
Protects cardiolipin and mitochondrial DNA from oxidative damage — relevant in age-related mitochondrial dysfunction.
Evidence summary
Sechi G et al. (Prog Neuropsychopharmacol Biol Psychiatry, 1996) demonstrated significant clinical improvement in Parkinson's patients receiving IV glutathione.
Mischley LK et al. (Movement Disorders, 2017) — RCT of intranasal glutathione in early Parkinson's disease.
Sonthalia S et al. (Indian J Dermatol Venereol Leprol, 2018) reviewed IV glutathione for skin lightening and pigmentation outcomes.
Bishayee A et al. (Curr Pharm Des, 2014) reviewed glutathione's role in chemoprotection and liver detoxification pathways.
Dosing and clinical context
General clinical context only. Kindr Health physicians determine the appropriate dose and protocol for each patient based on history and labs. This is not a prescription or dosing recommendation.
Routes: subcutaneous injection, IV infusion, nebulized (for pulmonary indications), and oral liposomal (lower bioavailability).
Frequency varies by indication — weekly IV infusions are common in functional medicine; daily subcutaneous dosing for shorter courses.
Often co-prescribed with NAC (N-acetylcysteine), the cysteine precursor that supports endogenous GSH synthesis.
Safety and contraindications
Very well tolerated. The most-reported issue is sulfur-smelling breath or mild GI upset.
Contraindications: known sulfur allergy, pregnancy/lactation (insufficient data), active asthma if nebulized (rare bronchospasm).
Skin lightening is a recognized effect — patients seeking even pigmentation should be advised.
Compounded by licensed 503A pharmacies in the U.S.; not FDA-approved for the indications described above.
Who it's typically considered for
- Adults with high oxidative-stress burden (smokers, environmental exposure, chronic infection)
- Patients with hepatic strain or polypharmacy needing Phase II detox support
- Dermatology patients with melasma or post-inflammatory hyperpigmentation
- Longevity-oriented patients pursuing redox-balance and mitochondrial-protection protocols
Frequently asked questions
Is glutathione a peptide?
Technically yes — it is a tripeptide of glutamate, cysteine, and glycine. It is sometimes excluded from 'peptide' lists because it is far smaller than most therapeutic peptides.
Oral vs IV glutathione?
Oral glutathione has limited bioavailability (degraded by GI proteases). Liposomal oral preserves more. IV and subcutaneous bypass GI entirely — most efficient route.
Glutathione vs NAC?
NAC is the precursor — it provides the rate-limiting cysteine for endogenous GSH synthesis. Glutathione is the active molecule itself. Many protocols use both.
Does glutathione lighten skin?
Yes — through tyrosinase inhibition. Patients seeking even pigmentation should be informed; those who want lightening of melasma can benefit.
How long until I notice effects?
Detox and energy effects within 1–2 weeks. Skin changes over 4–8 weeks. Liver-function-test improvements at 4–12 weeks.
Is IV glutathione FDA-approved?
No. Compounded glutathione is dispensed by licensed 503A pharmacies under physician prescription.
Sources
- Sechi G et al. Reduced intravenous glutathione in early Parkinson’s disease. Prog Neuropsychopharmacol Biol Psychiatry (1996). — pubmed.ncbi.nlm.nih.gov/8993056
- Mischley LK et al. Phase IIb study of intranasal glutathione in Parkinson’s disease. Mov Disord (2017). — pubmed.ncbi.nlm.nih.gov/28198038
- Honda Y et al. Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study. BMC Gastroenterol (2017). — pubmed.ncbi.nlm.nih.gov/28789631
Considering Glutathione?
A Kindr Health physician reviews every longevity intake — peptides are prescribed only when medically indicated based on your history and labs. There is no charge for the initial review.
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Medically reviewed by Dr. Ana Lisa Carr, MD, MBA
Board-Certified Family Medicine Physician · Lead Provider / Medical Reviewer
NPI 1689841744 · Last reviewed: May 10, 2026
Last reviewed May 10, 2026. Compounded medications are prepared by FDA-registered 503A pharmacies and are not FDA-approved drug products. Prescriptions require a clinical evaluation; a Kindr Health physician determines eligibility. Not for use in pregnancy. This page provides educational information and is not medical advice.