Not approved
FDA (U.S.): Not approved as a drug; sold as a dietary supplement.
EMA (EU): No EMA authorization. In Italy there are national injectable medicines (e.g., Tationil 600 mg) indicated to prevent cisplatin neuropathy; in the rest of the EU it is sold mainly as a supplement.
250–1,000 mg/day in a liposomal formulation.
Pilot study (12 healthy adults, 1 month): oral liposomal glutathione (500-1000 mg/day) raised blood glutathione stores and improved markers of immune function. Regular glutathione is poorly absorbed; the liposomal form aims to solve this. Small pilot.
View the study (study) →⏱ 3 min read
Glutathione is the most abundant and most important intracellular antioxidant in the body, a tripeptide formed by three amino acids (glutamate, cysteine, glycine) present at millimolar concentrations in practically every cell in the body, especially concentrated in the liver, where it reaches its highest concentrations; its biological function is multiple and central: it directly neutralizes reactive oxygen and nitrogen species, regenerates other antioxidants (vitamin C, vitamin E) after use, conjugates and excretes xenobiotics and heavy metals through phase II hepatic detoxification, keeps protein sulfhydryl groups in a functionally reduced state, and modulates cellular redox signaling.
The main pharmacokinetic problem with glutathione as an oral supplement is its poor systemic bioavailability: the intestinal mucosa and, subsequently, the liver efficiently hydrolyze the tripeptide into its constituent amino acids during absorption, so conventional oral glutathione barely raises plasma and intracellular concentrations of intact glutathione by significant amounts; liposomal formulations and amino acid precursors (especially N-acetylcysteine, the limiting amino acid in endogenous synthesis) are the most efficient pharmacological alternatives for actually increasing the body's glutathione pool.
Liposomal formulations encapsulate glutathione in lipid vesicles that theoretically protect the tripeptide from gastrointestinal degradation and allow more efficient absorption; several small studies have documented significant increases in markers of systemic glutathione with liposomal glutathione supplementation over weeks to months, data suggesting better real bioavailability than conventional oral glutathione; however, the magnitude of the effect remains modest compared with supplementation with N-acetylcysteine or with the combination of cysteine-glycine-glutamate at adequate doses, which are cheaper and well-studied options.
N-acetylcysteine (NAC, with its own profile in this database) is probably the most efficient and inexpensive option for increasing intracellular glutathione concentrations: NAC provides cysteine (the limiting amino acid in endogenous synthesis) in a stable and bioavailable form, allows cells to synthesize glutathione when and where it is needed, and has a well-established clinical profile in multiple indications (acetaminophen hepatotoxicity, COPD with excess mucus, glutathione deficits associated with various conditions).
In liver disease (steatosis, viral hepatitis, toxic liver disease), data on liposomal glutathione are preliminary but suggest favorable effects on transaminases and on overall liver function, an indication consistent with the central role of glutathione in hepatic metabolism; in exposure to xenobiotics, heavy metals, or significant oxidative stress, supplementation with glutathione precursors has a reasonable mechanistic basis, although specific clinical data are heterogeneous.
The doses studied with liposomal glutathione range from 250 to 1,000 milligrams daily, divided into one or two doses with or without food; commercial products are usually liposomes in liquid suspension with a characteristic sulfurous-bitter taste that is hard to mask; the alternative with N-acetylcysteine at 600-1,200 mg/day divided is significantly cheaper and has stronger clinical support for equivalent indications.
Generally well tolerated at the doses studied; the adverse effects described are rare and mild (digestive discomfort, persistent unpleasant taste); people with active asthma may have a transient bronchial exacerbation from inhaling sulfurous vapors; those taking nitroglycerin or other nitric oxide donors may have a mild potentiation of the effect; in pregnancy and breastfeeding, specific data on use as a supplement are limited; commercial products vary enormously in the quality of the liposomalization (true liposomal encapsulation requires specific pharmaceutical processes and is not trivial), and many products sold as "liposomal" are formulated as simple emulsions without the pharmacokinetic properties of true liposomes; premium products are expensive, and the cost-effectiveness compared with oral NAC (much cheaper and with probably equivalent or superior efficacy for increasing the intracellular glutathione pool) should be weighed carefully; commercial claims about "deep cleansing," "cellular detoxification," and the like are simplistic extrapolations of the biochemical role of glutathione without support in rigorous clinical data.
Information, not medical advice. Scientific evidence reflects the quality of the studies.