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Limited evidenceLongevity & antioxidants

S-Acetyl Glutathione

An acetylated glutathione claimed to survive digestion better than the plain form. Safety has been assessed, but no trial has shown it outperforms ordinary oral glutathione or produces a clinical benefit.

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What the science says

  • Raising body glutathione stores Limited evidence

    A randomized controlled trial of plain oral glutathione (250 or 1,000 mg/day for six months) did increase glutathione in blood, erythrocytes and buccal cells, contradicting the claim that oral glutathione is entirely destroyed in the gut. That trial did not test the S-acetyl form, and no equivalent trial of S-acetyl glutathione has been published.

  • Superior absorption of the acetylated form Limited evidence

    The advantage of S-acetyl glutathione rests on pharmacokinetic reasoning and cell work rather than head-to-head human comparisons. A published safety assessment characterizes the ingredient for food use but does not demonstrate better bioavailability or any clinical outcome.

Dosage & safety

Studied doseNo efficacy-based dose. Products typically supply 100–300 mg/day; the plain glutathione trial used 250–1,000 mg/day.
SafetyA formal safety assessment supports use in foods and supplements at typical intakes, and plain oral glutathione was well tolerated over six months. Mild gastrointestinal upset is the main reported complaint. Not studied in pregnancy, breastfeeding or children; people on chemotherapy should ask their oncologist before taking antioxidant supplements.

How to take it

TimingTiming does not matter.
With food?Usually taken on an empty stomach, though no study has compared that with taking it with food.
Worth knowingPlain oral glutathione raised body stores over six months in a trial and costs a fraction of the acetylated form, which has no comparable human data.

Interactions

With medications

  • chemotherapy

    Glutathione is the cell's main detoxification pathway for platinum and alkylating agents, so high-dose supplementation during treatment is a legitimate question rather than a neutral one. ask your oncologist before taking it during treatment

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Is S-acetyl glutathione better absorbed than regular glutathione?

That claim is unproven: the case for S-acetyl glutathione rests on pharmacokinetic reasoning and cell work, with no head-to-head human comparison. Its safety assessment characterises the ingredient but shows no better bioavailability or clinical benefit, so the evidence is limited.

Does oral glutathione actually raise glutathione levels?

A randomized trial of plain oral glutathione at 250 or 1,000 mg/day for six months raised glutathione in blood, red cells and cheek cells. That trial did not test S-acetyl glutathione, which has no equivalent published trial.

How much S-acetyl glutathione should I take?

S-acetyl glutathione has no efficacy-based dose; products typically supply 100–300 mg/day, often on an empty stomach. Plain glutathione at 250–1,000 mg/day has better human data and costs a fraction of the acetylated form.

Is S-acetyl glutathione safe during chemotherapy?

Ask your oncologist first: glutathione is the cell's main detoxification pathway for platinum and alkylating chemotherapy drugs, so high-dose supplementation during treatment is not neutral. Otherwise S-acetyl glutathione's main reported side effect is mild stomach upset.

Scientific references

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