No glutathione dose is FDA-approved. The best oral trial used 250 or 1,000 mg a day for six months and raised the body’s glutathione stores.[1] Telehealth injections usually come as 200 mg/mL vials, with the dose set by the prescriber. IV doses sold for skin lightening lack evidence, and FDA warned in August 2026 about contaminated IV glutathione.[7]
Glutathione is a three-amino-acid antioxidant your cells make on their own. It is sold three ways: as an oral supplement, as a compounded injection from telehealth programs, and as an IV drip at clinics and med spas. Each route has a different dose range and a very different amount of evidence behind it. This page sets out the doses that trials actually tested, how to read an injection prescription in milligrams and units, and where the larger IV doses fall outside anything that has been shown to work. For what glutathione does and does not do, start with our glutathione evidence review.
Is there an approved glutathione dose?
No. Oral glutathione is sold as a dietary supplement, and the label dose on the bottle is the manufacturer’s choice. There is no FDA-approved injectable glutathione product either, so every injection or drip is compounded. On FDA’s list of substances nominated for 503A compounding, updated May 14, 2026, glutathione sits in Category 1, “bulk drug substances under evaluation.” That means FDA has not yet decided whether it belongs on the permanent list of substances pharmacies may compound.[8] It is not the same as approval, and it means no regulator has set a dose. The doses below are the ones researchers tested, plus the arithmetic for reading a compounded vial.
What oral glutathione doses did trials use?
The most useful trial is Richie and colleagues’ 2015 study at Penn State. Fifty-four healthy non-smokers took 250 mg or 1,000 mg of glutathione a day, or placebo, for six months. Blood glutathione rose at both doses by the first month. At six months the high dose had raised levels 30–35% in red cells, plasma and lymphocytes and 260% in cheek cells (P < 0.05). The low dose raised blood and red-cell levels by 17% and 29%. Levels went back to baseline after a one-month washout.[1]
An earlier trial by Allen and Bradley gave 40 healthy adults 500 mg twice a day (1,000 mg daily) for four weeks. It found no change in oxidative-stress markers and no change in glutathione status, with P = 0.38 and P = 0.27 on its two primary measures.[2] Read together, the two trials suggest that a month is too short and that oral glutathione works slowly, if it works at all, for the outcome you care about.
| Trial | Daily dose | Length | What changed |
|---|---|---|---|
| Richie 2015 (n = 54) | 250 mg or 1,000 mg | 6 months | Blood GSH up at both doses; +30–35% in several compartments on 1,000 mg; back to baseline 1 month after stopping |
| Allen 2011 (n = 40) | 1,000 mg (500 mg twice daily) | 4 weeks | No change in oxidative-stress markers or glutathione status |
| Weschawalit 2017 (healthy women) | 250 mg (reduced or oxidized form) | 12 weeks | Melanin index trended lower than placebo; fewer wrinkles at some sites |
| Oral skin trials pooled in Sarkar 2025 | 250 mg once or twice daily, or 500 mg once daily | Varied | Five RCTs reported a lower melanin index than placebo |
What doses did the skin-lightening trials use?
Skin lightening is the most heavily marketed use, and the oral trials for it used modest doses. Weschawalit and colleagues gave healthy women 250 mg a day of either reduced or oxidized glutathione for 12 weeks. Melanin index and UV spots trended lower than placebo, and some sites showed fewer wrinkles, with no serious side effects.[3] A 2025 systematic review in the International Journal of Dermatology pooled the evidence. Five randomized trials of oral glutathione at 250 mg once a day, 250 mg twice a day or 500 mg once a day lowered the melanin index against placebo. The effects were moderate and faded after stopping.[4]
IV is a different story. The same review found only one placebo-controlled IV trial, in which 6 of 16 people on glutathione improved against 3 of 16 on placebo, 37.5% vs 18.7% (P = 0.054, not significant). The authors concluded that “IV glutathione is contraindicated due to lack of efficacy and side effects.”[4] An earlier review in the same field described IV injections as popular with “no evidence to prove its efficacy,” and noted that the Philippine FDA had issued a public warning against IV glutathione for skin lightening.[5]
How do you read a glutathione injection in mg and units?
Compounded glutathione for injection is most often listed at 200 mg/mL in the telehealth programs we have reviewed, in vials of 5, 10 or 30 mL. The prescriber sets the dose and the schedule, and the pharmacy label sets the concentration, so both have to be read together. The conversion is the same as for any injectable: volume in mL = dose in mg ÷ concentration in mg/mL, and on a U-100 insulin syringe, units = mL × 100. Some glutathione prescriptions are written in milliliters for a syringe marked in mL rather than units, so check which one your pharmacy sent.
| Prescribed dose | At 200 mg/mL | On a U-100 syringe | Doses in a 10 mL vial (2,000 mg) |
|---|---|---|---|
| 100 mg | 0.5 mL | 50 units | 20 |
| 150 mg | 0.75 mL | 75 units | 13 (with 50 mg left) |
| 200 mg | 1.0 mL | 100 units | 10 |
| 400 mg | 2.0 mL | More than one 1 mL syringe | 5 |
How often to inject is the question with the least evidence behind it. Schedules vary by prescriber, and some programs are sold as one injection a week, but we could not find a randomized trial that tested any intramuscular or subcutaneous glutathione schedule for general wellness. What the oral data do show is that glutathione levels fall back within weeks of stopping, so any effect would depend on staying on it.[1] Our reconstitution calculator handles other concentrations.
How large are IV glutathione doses, and what has FDA warned about?
IV drips use much larger amounts than oral or injection programs. In a 2019 alert, FDA described seven patients at one clinic who each received 1,400 mg (7 mL of a 200 mg/mL solution) and a separate patient who received 2,400 mg. Patients developed nausea, vomiting, chills and body aches within minutes, and two were hospitalized. Testing found the glutathione ingredient carried bacterial endotoxin at five times the appropriate limit, and it had been labeled as a dietary supplement rather than a grade fit for injection.[6]
On August 27, 2026, FDA issued a new alert: at least 30 patients had adverse events after IV glutathione, including fever, chills, dizziness, signs of shock and sepsis-like symptoms, with some hospitalizations. Two Texas pharmacies recalled glutathione products over elevated endotoxin, and FDA told compounders not to use dietary-supplement-grade glutathione in injectables.[7]
Do side effects rise with the dose?
At oral doses up to 1,000 mg a day, the trials reported no serious adverse effects.[1][3] The safety problems documented so far cluster around IV use: endotoxin reactions from contaminated ingredients, and the side effects that led the 2025 review to reject IV glutathione for skin lightening.[4][7] There is no trial that maps intramuscular dose against side effects, so the honest answer for injections is that nobody has measured it.
Should glutathione be taken with NAD+?
Many longevity programs sell glutathione and NAD+ together, sometimes as a bundle. The two are linked in cell chemistry, but we found no controlled trial that tested the combination, at any dose, for any outcome. Each needs to be judged on its own evidence. For NAD+, see our NAD+ injections review. If you want to raise glutathione more cheaply, its precursor NAC has a longer research record; our glutathione vs NAC comparison sets the two side by side.
What does glutathione cost by route?
Oral glutathione costs the least and has the best-controlled data, compounded injections sit in the middle, and IV drips cost the most. Our glutathione cost guide breaks down each route. Telehealth services that prescribe glutathione alongside NAD+ are listed on our NAD+ therapy page.
The bottom line
The only glutathione doses with a positive long-term trial are oral: 250 to 1,000 mg a day, taken for months. Injection programs have a standard concentration but no tested schedule, and IV drips use the largest doses with the least support and the clearest record of harm. If you use an injection, know the milligrams, the concentration and the pharmacy, and treat the prescriber’s schedule as a choice rather than a proven protocol.