Glutathione

What it is

Glutathione (GSH) is a small peptide of three amino acids. In the circulation it is broken down quickly by gamma-glutamyltranspeptidase, an enzyme on the outer surface of cells, into glutamate, cysteine and glycine [2]. The reduced form is an antioxidant: in the laboratory it suppressed reactive oxygen species in fibroblasts at concentrations of 1–10 mM, about a thousand times higher than the micromolar levels normally found in blood [2]. Healthy adults already carry glutathione in plasma; the baseline total was 17.5 ± 13.4 µmol/L in one study [1]. The injectable products people receive are compounded, usually as an intravenous solution such as the 200 mg/mL preparations named in FDA reports [6][8]. Compounded drugs are not FDA-approved [9].

How it works

Intravenous glutathione is best understood as a way to deliver cysteine, the amino acid cells need to make their own glutathione [1]. In ten healthy volunteers, an infusion of 2 g/m² raised plasma total glutathione from 17.5 to 823 µmol/L and plasma cysteine from 8.9 to 114 µmol/L, while total cyst(e)ine fell, which the authors interpreted as increased uptake of cysteine into cells; urinary excretion of glutathione rose 300-fold over the following 90 minutes [1]. In seven young men, most of the infused glutathione was oxidized and disappeared from the circulation within minutes, and its three amino acids peaked in blood at 10 minutes [2]. Those authors concluded that keeping a high blood level by infusion is impractical and that any antioxidant effect would have to come from the metabolites [2].

What the evidence shows

The human data behind injectable glutathione are pharmacokinetic studies in healthy people, not outcome trials: ten volunteers in Switzerland in 1991 [1] and seven medical students in Korea in 2005 [2][3]. The 1991 paper frames its work around the use of high-dose glutathione to protect the kidney and bladder during cisplatin or oxazaphosphorine chemotherapy [1]; the 2005 paper was trying to work out how to treat paraquat poisoning [3]. Neither studied wellness, skin, fatigue or detox uses, and no FDA-approved injectable glutathione product exists [9]. FDA reviews compounded drugs only after the fact: it does not verify their safety, effectiveness or quality before they are marketed [9]. What FDA has documented in detail is harm from contaminated product, described below [6][7][8].

Regulatory status

Glutathione is not an FDA-approved injectable drug [9]. It appears in Category 1 of FDA’s list of substances nominated for 503A compounding, updated May 14 2026, meaning it is still under evaluation for the bulks list [4]. For Category 1 substances FDA says it does not intend to take action against a compounder, provided the conditions in its interim guidance are met, until it decides on listing [5]. FDA has issued repeated quality warnings. On Feb 1 2019 it warned compounders not to use one distributor’s dietary-supplement-grade L-glutathione powder after seven patients reacted to infusions; FDA testing found endotoxin up to five times the appropriate limit [6]. On Aug 27 2026 FDA said it was aware of at least 30 patients with adverse events after intravenous glutathione made from a dietary-supplement-grade lot, and that two Texas pharmacies had recalled product [7]. A further nationwide recall of six lots followed in September 2026 [8].

Half-life and what it means for a level curve

The reference half-life in STACK is 0.235 hours, which is 14.1 minutes. Aebi et al. measured an elimination rate constant of 0.063 per minute after intravenous infusion in ten healthy volunteers, corresponding to a half-life of 14.1 ± 9.2 min, with a volume of distribution of 176 ± 107 mL/kg [1]. Hong et al. found that infused glutathione disappeared with a half-life of about 10 min in seven young men [2]. The two agree within their error bars; STACK uses the 1991 value, the larger study. There is no subcutaneous or intramuscular half-life in the literature. With a 14 min half-life, a level reaches about 97% of steady state after roughly five half-lives, a little over an hour, and returns to baseline just as fast, so the curve is a short spike around each infusion rather than a plateau. STACK’s curve is an estimate from this published half-life, not a blood level.

Reported side effects

In the 2005 study no side effects were observed after infusion in the seven volunteers [2]. The reactions FDA has documented come from endotoxin contamination of the powder used to make the injection, not from glutathione itself. In January 2019, seven clinic patients developed nausea, vomiting, lightheadedness, chills, body aches and sneezing within minutes of an infusion, and one had low blood pressure and difficulty breathing and was hospitalized [6]. The events reported to FDA in 2026 included fever, chills, pain, dizziness, signs of shock and sepsis-like symptoms, some leading to hospitalization [7]. The September 2026 recall notice listed fever, chills, chest pain, nausea or vomiting, headache and malaise from nine reports [8]. Fever or chills soon after a dose are a reason to call your prescriber; FDA asks that such events be reported to MedWatch [7].

Storage and handling

There is no approved label, so the compounding pharmacy’s label governs storage, and its beyond-use date is the expiry that matters. The products in the September 2026 recall were 30 mL multidose vials, each with a lot number and a beyond-use date printed on the label [8]. Keep those details with the vial: FDA recalls and warnings identify product by lot, and health care professionals are urged to check with their compounder about the source of the glutathione used [7]. FDA does not verify the quality of compounded drugs before they are sold, and poor compounding practice can produce contamination or wrong strength [9]. Glutathione usually arrives as a ready solution; if yours is a powder, STACK’s reconstitution calculator does the concentration math without suggesting what to take.

What STACK tracks for it

STACK logs each glutathione dose as your prescriber wrote it, in mg, with the route, the date and time, and how long an infusion took. The estimated-level curve uses the 14.1 min intravenous half-life, so it shows a brief peak around each dose and nothing between doses; that is expected. Side-effect entries are built around the reactions FDA has documented, fever, chills, nausea, dizziness and chest pain, with a time stamp so you and your prescriber can see how soon after a dose they began [6][7][8]. Vial inventory records the pharmacy, lot number and beyond-use date so a recall can be matched to what you have. Weight and other compounds in your plan share the same timeline.

The reference half-life in STACK

STACK's simulator and the app use 14.1 min for Glutathione: ~10–14 min (14.1 ± 9.2 min; 'about 10 min' in a second study), intravenous. Measured in: 10 healthy volunteers, intravenous infusion (Aebi 1991); 7 healthy young men, intravenous (Hong 2005).

Estimate only. Modelled from the published half-life you selected and the doses you logged — not a measured blood level. Do not use it to make medication decisions.

Free tools for Glutathione

Read next

Sources

Every URL below was fetched and checked on 2026-09-24. Bracketed numbers in the text link here.

1. TrialHigh-dose intravenous glutathione in man. Pharmacokinetics and effects on cyst(e)ine in plasma and urine (Aebi et al. 1991)
2. TrialPharmacokinetics of Glutathione and Its Metabolites in Normal Subjects (Hong et al. 2005, full text)
3. TrialPharmacokinetics of glutathione and its metabolites in normal subjects (Hong et al. 2005, PubMed record)
4. FDABulk Drug Substances Nominated for Use in Compounding Under Section 503A (updated May 14, 2026)
5. FDABulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act
6. FDAFDA highlights concerns with using dietary ingredient glutathione to compound sterile injectables (Jun 7 2019)
7. FDAFDA reminds compounders not to use dietary supplement grade glutathione for injectables (Aug 27 2026)
8. FDACentric Compounding Issues Nationwide Recall of Glutathione, Myer's Cocktail, and Tri-Immune Boost Due to Elevated Endotoxin Levels (Sep 2026)
9. FDACompounding and the FDA: Questions and Answers