Glutathione Dosage: How Much Is Actually Used, by Route

The short answer

How much glutathione do people actually take?

There is no single established dose of glutathione. Unlike a vitamin with a recommended daily allowance, glutathione has no RDA, no FDA-approved dosing for general wellness, and no consensus guideline. What exists instead is a range of doses used in published studies and in clinical practice.

Across oral supplement research, the range is roughly 250 to 1,000 mg per day, and 500 mg daily is the dose most often studied. The most cited trial — Richie and colleagues, 2015 — gave healthy adults 250 mg or 1,000 mg daily for six months and measured meaningful increases in body glutathione stores at both doses.

Injectable and intravenous glutathione are a different category entirely. They are prescription-only, prepared by a compounding pharmacy, and dosed by the prescribing clinician — commonly somewhere between 600 and 2,400 mg per session, depending on what is being treated and how the patient responds.

Dosage by route

Glutathione dosage by route of administration

Route matters more than almost anything else here, because oral glutathione is poorly absorbed. Swallowed glutathione is largely broken down in the gut into its component amino acids before it reaches circulation, which is why oral and intravenous doses are not comparable and cannot be converted into one another.

Oral glutathione

Oral glutathione dosage

250–1,000 mg per day is the range used in most oral research, and 500 mg daily is the usual middle ground.

What the research used

The six-month trial most often cited used 250 mg and 1,000 mg daily and found increases in glutathione stores in blood, red cells and buccal cells at both doses, with the higher dose producing larger increases. Shorter studies have used up to 1,000 mg daily without notable safety problems.

The absorption problem

Standard oral glutathione has poor bioavailability. Much of an oral dose is hydrolysed in the digestive tract into cysteine, glycine and glutamate, and the body then has to rebuild glutathione from those pieces. This is the single biggest reason oral dosing is higher than injectable dosing and still produces smaller changes in circulating levels.

It is also why raising the oral dose past roughly 1,000 mg a day tends to produce diminishing returns rather than a proportional benefit.

Liposomal glutathione

Liposomal and sublingual glutathione dosage

500–1,000 mg per day is typical for liposomal forms.

Liposomal glutathione wraps the molecule in a lipid layer intended to protect it through the gut, and sublingual forms aim to bypass digestion altogether. Both are marketed on better absorption than standard oral glutathione, and small studies do suggest liposomal delivery raises blood levels more effectively.

The evidence base is thinner than the marketing implies. Product quality also varies considerably between manufacturers, and "liposomal" is not a regulated term — it does not guarantee the formulation does what the label says.

Injection and IV

Injectable and IV glutathione dosage

Injectable glutathione is prescription-only in the United States and is not an FDA-approved drug. It is prepared by compounding pharmacies, which means it has not gone through FDA review for safety, effectiveness or manufacturing quality.

Ranges used clinically

Intramuscular and subcutaneous doses commonly fall between 200 and 600 mg, given one to three times a week. Intravenous doses are higher — commonly 600 to 2,400 mg per session — and are usually given as a course over several weeks rather than indefinitely.

Research in Parkinson's disease, one of the few areas with controlled IV data, has used doses around 1,400 mg three times weekly. Results there have been mixed, and glutathione is not an approved treatment for Parkinson's.

Why these are not self-administered

Dose, dilution, infusion rate and sterility all matter, and none of them are things a label can manage for you. A clinician sets the dose against your indication, weight, labs and medication list, and adjusts it based on response.

NAC as an alternative

NAC dosage — raising glutathione indirectly

600–1,800 mg per day is the usual range for N-acetylcysteine.

NAC is not glutathione. It supplies cysteine, the rate-limiting amino acid your body needs to make glutathione itself, and it is generally better absorbed orally than glutathione is. For some people it is a more practical way to raise glutathione than swallowing the molecule directly.

It is also the approach with the longest clinical track record — NAC has been used in hospital medicine for decades, though at doses well above what is used as a supplement.

What changes your dose

What actually determines your dose

• Route. The single biggest factor. Oral and IV doses are not interchangeable.
• Why you are taking it. General antioxidant support, oxidative stress on labs, and adjunct use alongside another therapy are not the same clinical question.
• Body size and baseline status. Starting glutathione levels vary widely, and age, chronic illness, smoking and alcohol all deplete them.
• Other medications. Glutathione and NAC both interact with some drugs, and NAC in particular should be reviewed against blood thinners and nitroglycerin.
• Response over time. A dose that is right at week one is not automatically right at week twelve.

At Protocol Health, glutathione is used as part of a plan built on labs and medical history rather than as a standing product at a fixed dose. If injectable or IV glutathione is appropriate, the dose is set and adjusted by the prescribing clinician.

Safety

Is glutathione safe at these doses?

Oral glutathione is generally well tolerated in the ranges above. Reported side effects are mostly mild and digestive — bloating, cramping, loose stools — and some people report headache.

Injectable and IV glutathione carry the risks that come with any injection or infusion: injection-site reactions, infection if sterile technique is not maintained, and rarely, allergic reactions. Because compounded products are not FDA-reviewed, quality depends heavily on the pharmacy.

People with asthma should be cautious, as bronchospasm has been reported with inhaled and occasionally injected glutathione.

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Related at Protocol Health

• Glutathione: The Master Antioxidant →
• IV Therapy →