Glutathione Dosage: What the Research Used, by Route

Route matters more than anything else here, because swallowed glutathione is largely broken down in the gut before it reaches circulation. An oral dose and an intravenous dose of the same size do not deliver remotely the same amount, and cannot be converted into one another.

These are ranges reported in the literature and in common clinical practice. They are not a recommendation, and the prescription routes are dosed and administered by a clinician.

200–600 mg per dose, one to three times weekly is the range most commonly used for intramuscular and subcutaneous glutathione.

Injection bypasses the digestive tract entirely, which is the whole point. Our glutathione injections are prescribed on that basis, and glutathione side effects covers what to watch for. Because none of the dose is lost to gut breakdown, the numbers are far smaller than oral doses while delivering considerably more into circulation.

What determines where in the range someone lands

• Why it is being used at all — general antioxidant support sits at a different point than adjunct use alongside another therapy.
• Body size, age, and baseline oxidative stress markers where they have been measured.
• Tolerance, which is usually good, but injection-site reactions do occur.
• Response over time. A starting dose is a starting point, not a setting.

At Protocol MD, glutathione injections are physician-prescribed after review, and the dose is set and adjusted by the prescribing clinician rather than chosen from a menu.

600–2,400 mg per session is the usual range for intravenous glutathione, given once or twice weekly and typically as a defined course rather than indefinitely.

IV is the highest-delivery route and the most resource-intensive. The controlled research is thin, and the area with the most data — Parkinson's disease — used doses around 1,400 mg three times weekly with mixed results. Glutathione is not an approved treatment for Parkinson's, and that literature is cited here as the source of the dose range, not as evidence of benefit.

The practical difference between IV and injection is usually convenience and cost rather than outcome. IV versus injection is covered in more detail here.

250–1,000 mg daily covers most oral research, and 500 mg daily is the dose studied most often. A six-month trial in healthy adults used 250 mg and 1,000 mg daily and measured increases in body glutathione stores at both, with the larger dose producing larger increases.

Why oral doses are larger and still do less

Standard oral glutathione has poor bioavailability. Much of it is hydrolysed in the gut into cysteine, glycine and glutamate, and the body then rebuilds glutathione from those parts. This is why raising an oral dose beyond about 1,000 mg a day tends to produce diminishing returns rather than a proportional effect.

Liposomal and sublingual

500–1,000 mg daily is typical. These formulations aim to protect the molecule through the gut or bypass digestion altogether, and small studies do suggest better absorption than standard oral. The evidence base is thinner than the marketing, and "liposomal" is not a regulated term.

Worth saying plainly, even though we sell the injectable: for someone with no specific clinical reason to use a prescription route, oral or liposomal glutathione is inexpensive, available without a prescription, and reasonable.

600–1,800 mg daily is the usual supplement range for N-acetylcysteine.

NAC is not glutathione. It supplies cysteine, the rate-limiting amino acid the body needs to build glutathione itself, and it absorbs orally better than glutathione does. For some people it is a more practical way to raise glutathione than swallowing the molecule. It also has the longest clinical track record of anything in this article, though hospital use is at doses far above supplement ranges.

NAC interacts with some medications, and is worth reviewing against blood thinners and nitroglycerin specifically.

Glutathione is not an FDA-approved drug. Injectable glutathione is prepared by 503A compounding pharmacies, which means it has not been through FDA review for safety, effectiveness or manufacturing quality. That is true of our product as much as anyone else's, and it is the honest frame for every number above.

The FDA has also issued specific warnings about injectable glutathione marketed for skin lightening. The evidence for that use is weak and the products involved are frequently unregulated imports.