Evidence-based·Last reviewed June 1, 2026·How we grade evidence

Acetyl-Glutathione

ProteinGlutathione derivative

Acetyl-glutathione (S-acetyl-glutathione, sAG) is glutathione modified with an acetyl group on the cysteine thiol, sold as an 'orally bioavailable' alternative to standard oral GSH. The chemistry rationale is plausible — acetylation may protect GSH from gut hydrolysis. The honest evidence picture is that direct human RCT data for sAG specifically is sparse (one Italian pilot in fatty liver, plus cell-culture work). Meanwhile, well-designed trials of standard oral GSH (Richie 2015) and N-acetylcysteine (NAC, decades of trials) demonstrate the body CAN raise its own glutathione from cheaper precursors. The 'best form' marketing for sAG outruns the comparative trial evidence.

Quick decision guide

May help most

Adults who specifically want to try an oral GSH-delivery strategy and prefer the acetylated form (often more expensive), and who understand the comparative evidence base is limited. For most goals, NAC or whey protein are cheaper, better-studied ways to raise intracellular GSH.

Common dosing range

100–300 mg/day on an empty stomach. The Italian fatty liver pilot used 100 mg/day for 3 months. Higher doses (up to 500 mg/day) are marketed but not better-studied.

When to expect effects

Weeks for any biomarker change; clinical-endpoint timelines are not well defined.

Watch out for

Generally well tolerated. The biggest issue is paying premium prices for a delivery form with thin comparative-trial evidence vs cheaper precursors (NAC, whey protein). Asthma patients should be aware of rare bronchoconstriction reported with high-dose NAC; sAG has too little clinical data to characterize the same risk.

Evidence snapshot

Cell-culture intracellular GSH deliveryEmerging
Pilot in NAFLD (open-label)Low
Comparative head-to-head vs liposomal / NACLow
Standard oral GSH (Richie 2015 RCT)Moderate

What is it

Acetyl-glutathione (S-acetyl-L-glutathione) is a modified form of glutathione, the body's main intracellular antioxidant. Acetylation is intended to improve oral bioavailability and stability compared with standard reduced glutathione.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You've already tried NAC and prefer to spend on a different GSH delivery strategy
You're working with an integrative-medicine clinician who has a specific reason for choosing sAG
Cost is not a major factor and you specifically want the acetylated form
You're using a third-party-tested product with verified content

Probably skip if…

You haven't tried NAC (N-acetylcysteine) — it's far cheaper, far better-studied as a GSH precursor, and is the standard initial choice
You're comparing 'best oral GSH form' purely on advertising — head-to-head trial data are insufficient to crown a winner
You're using it for vague 'detox' or 'anti-aging' claims — these aren't validated indications
You're hoping it will reverse a serious chronic disease without other treatment — evidence doesn't support that
You have asthma — rare bronchoconstriction reported with high-dose oral GSH/NAC; discuss with your clinician
You expect IV-GSH-equivalent effects from an oral form — different bioavailability ceilings

Evidence at a glance

Intracellular glutathione delivery (mechanistic)

Mixed Evidence
Effect
Improved intracellular delivery in cell culture; uncertain magnitude in humans
Best fit
No established clinical population based on mechanism alone
Time
Not established for clinical endpoints

Non-alcoholic fatty liver disease (NAFLD)

Mixed Evidence
Effect
Open-label pilot reported significant reductions in liver enzymes and lipids over 3 months
Best fit
Patients in integrative care where clinician and patient understand the evidence is preliminary
Time
Weeks to months in the pilot trial

Raising whole-blood glutathione (general)

Mixed Evidence
Effect
Standard oral GSH raises whole-blood GSH ~30–35% at 1 g/day over 6 months (Richie 2015); direct sAG comparison missing
Best fit
Adults who specifically want a non-NAC GSH strategy and have the budget
Time
Weeks–months

Evidence for 3 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Intracellular glutathione delivery (mechanistic)

Mechanism only
Mixed Evidence

Cell-culture studies (Cacciatore 2010 review and underlying primary work) demonstrate that S-acetyl-glutathione enters lymphocytes at higher concentrations than equimolar standard GSH, supporting the rationale that acetylation protects the molecule during transit and improves cellular uptake. Translating cell-culture evidence to human clinical outcomes is a substantial inferential leap — and direct head-to-head bioavailability studies in humans (sAG vs liposomal GSH vs standard oral GSH vs NAC) are not robustly published.

Effect size
Improved intracellular delivery in cell culture; uncertain magnitude in humans
Time to effect
Not established for clinical endpoints
Best fit
No established clinical population based on mechanism alone
Less likely
Anyone treating mechanism-only data as a replacement for clinical evidence

Bottom line: Plausible mechanism, thin human evidence. NAC has a much larger clinical evidence base for raising intracellular GSH and costs a fraction as much.

SourceCacciatore et al., 2010 — PMC — Molecules (review)

Non-alcoholic fatty liver disease (NAFLD)

Disease adjunct
Mixed Evidence

Buonocore 2016 reported a small open-label pilot of S-acetyl-glutathione 100 mg/day for 3 months in 50 NAFLD patients, with significant decreases in liver enzymes (ALT, AST, GGT) and lipid markers (total cholesterol, triglycerides). The trial was open-label without placebo control, single-center, and small. The signal is interesting but should not be taken as evidence-based recommendation until replicated in a randomized, placebo-controlled setting. NAFLD treatment guidelines currently emphasize weight loss, dietary change, and vitamin E (for biopsy-proven NASH).

Effect size
Open-label pilot reported significant reductions in liver enzymes and lipids over 3 months
Time to effect
Weeks to months in the pilot trial
Best fit
Patients in integrative care where clinician and patient understand the evidence is preliminary
Less likely
Anyone using it as a substitute for evidence-based NAFLD management (weight loss, exercise, treating metabolic syndrome)

Bottom line: Interesting pilot, not yet evidence-based. Standard-of-care NAFLD management (weight loss, exercise, treating metabolic syndrome) is far better-supported.

SourceBuonocore et al., 2016 — Italian Journal of Gastroenterology and Hepatology / Minerva Gastroenterologica

Raising whole-blood glutathione (general)

Supplement benefit
Mixed Evidence

Richie 2015 demonstrated that standard oral GSH at 250 or 1,000 mg/day for 6 months raises whole-blood and tissue GSH meaningfully — challenging the older dogma that oral GSH is non-bioavailable. This trial used standard GSH, not the acetylated form. The Richie data suggest that paying a premium for sAG specifically may not be necessary if the goal is simply raising blood GSH; standard oral GSH appears to work given enough time. Liposomal GSH (separate evidence base) and NAC are other commonly used routes.

Effect size
Standard oral GSH raises whole-blood GSH ~30–35% at 1 g/day over 6 months (Richie 2015); direct sAG comparison missing
Time to effect
Weeks–months
Best fit
Adults who specifically want a non-NAC GSH strategy and have the budget
Less likely
Anyone hoping sAG is dramatically better than standard oral GSH or NAC — no head-to-head trial data supports that

Bottom line: Multiple routes raise blood GSH. Acetylated form's premium pricing isn't yet matched by premium comparative evidence vs cheaper standard GSH or NAC.

Evidence is mixed

The published evidence base supports multiple GSH-raising strategies (oral standard, oral liposomal, NAC precursor). Direct comparative trials of acetyl-GSH vs these alternatives are not robustly published. Premium pricing on sAG is not yet matched by premium comparative evidence.

SourceRichie et al., 2015 — European Journal of Nutrition· conflictingCacciatore et al., 2010 — PMC — Molecules (review)· conflicting
SourceRichie et al., 2015 — European Journal of NutritionAllen & Bradley, 2011 — Journal of Alternative and Complementary Medicine

How it works

Standard reduced glutathione (GSH) is poorly absorbed orally and rapidly broken down. Acetyl-glutathione has been proposed as a more orally bioavailable form because the acetyl group may protect against enzymatic breakdown until the molecule is inside the cell. In the cell, the acetyl group is removed to release active glutathione, which participates in redox cycles and conjugation reactions that detoxify reactive species. Independent clinical confirmation of meaningfully improved bioavailability over standard glutathione is limited.

How to take it

1. Typical dose
• Typical: 100–300 mg/day • Italian NAFLD pilot used 100 mg/day for 3 months • Higher doses (300–500 mg/day) are marketed but not better-studied • On an empty stomach (15–30 min before food) to maximize intact absorption
2. Higher studied dose
Up to 300 mg/day in the limited published data. Higher doses haven't been studied in trials and don't have an evidence-based ceiling.
3. Timing
Empty stomach, ideally morning. Some clinicians split into morning + evening doses if the daily total is ≥200 mg.
4. With food
Without food — proteases in food disrupt the delivery rationale.
5. Split dosing
Optional. Some users split into 2 doses for steadier blood levels.
6. How long to try
At least 8–12 weeks to assess effect on intended biomarkers (ALT, AST, GGT for liver context; oxidative stress markers if measured). The Italian pilot used 3 months.

What to track

Liver enzymes (ALT, AST, GGT) if using for NAFLD context
Oxidative-stress biomarkers (8-OHdG, F2-isoprostanes) if measured by your clinician
Whole-blood or erythrocyte GSH (specialty labs only)
Subjective energy / cognitive symptoms (anecdotal, not validated endpoints)
Cost-vs-effect — be willing to switch to NAC or standard GSH if no perceptible benefit at 3 months

Bottom line: Try 100–200 mg/day empty-stomach for 12 weeks. If you don't see a meaningful biomarker change or subjective effect, consider whether the premium pricing of sAG justifies continued use vs cheaper alternatives.

6 commercial forms

Compare the main delivery options and what they’re best suited for.

S-Acetyl-Glutathione capsule (sAG, this page)

Acetylated oral

Glutathione with an acetyl group on the cysteine thiol. Mechanism rationale is to resist gut hydrolysis. Limited human RCT data; one Italian pilot in NAFLD; cell-culture support. Generally well tolerated.

Mechanism plausible; direct human comparative evidence limited.

Standard oral L-glutathione (reduced GSH)

Cheaper, surprisingly effective

Standard reduced glutathione in capsule form. Once thought to be entirely non-bioavailable, but Richie 2015 RCT showed 1 g/day over 6 months raises whole-blood GSH ~30–35%. Far cheaper than sAG; substantial trial evidence.

Trial-tested at chronic dosing; raises blood GSH with patience.

Liposomal glutathione

Lipid-encapsulated

GSH encapsulated in phospholipid vesicles, marketed for improved gut absorption. Some pilot data suggest better tissue delivery than standard oral GSH; head-to-head vs sAG is not robust.

Lipid carrier; some bioavailability advantage signals.

N-Acetylcysteine (NAC)

Cheapest, best evidence base

Cysteine precursor for de novo GSH synthesis. Decades of RCT evidence across mucolytic, hepatoprotective (acetaminophen overdose), and antioxidant uses. Pennies per dose vs premium sAG. NAC is the standard first choice for raising intracellular GSH cheaply.

Cysteine precursor; mature evidence base; FDA-approved as a drug for some uses.

Intravenous (IV) glutathione

Highest bioavailability

Direct IV infusion bypasses gut entirely. Used off-label in some integrative clinics, with mixed trial results in Parkinson's disease and other contexts. Requires clinical setting and isn't a self-supplement option.

Bypasses GI tract entirely; clinical setting only.

Topical / transdermal glutathione

Unproven

Creams and patches marketed for skin lightening and 'detox.' Absorption through intact skin is poor for a tripeptide of this size; clinical evidence is essentially absent. Avoid.

Very poor transdermal absorption; not evidence-supported.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

mild GI upsetsulfur-like burping (from the cysteine moiety)headache (uncommon)minor changes in stool (rare)

Serious risks

Who should avoid it

Pregnancy & breastfeeding

Safety of acetyl-glutathione during pregnancy and breastfeeding has not been studied. Standard recommendation is to avoid non-essential supplements during pregnancy; if a GSH-raising strategy is medically indicated, discuss with your obstetrician and weigh against better-characterized alternatives.

SourceMemorial Sloan Kettering Cancer Center — About Herbs — Glutathione

Bottom line: Generally well tolerated in healthy adults. The honest concern isn't acute safety so much as paying premium prices for a delivery form whose comparative-trial evidence is limited vs cheaper, better-studied alternatives.

Interactions

chemotherapy (platinum agents, anthracyclines)Moderate

Many chemotherapies use intracellular oxidative stress as part of their cytotoxic mechanism. Boosting intracellular GSH could antagonize the chemo's intended effect. Discuss any GSH-raising supplement with your oncologist before starting.

SourceMemorial Sloan Kettering Cancer Center — About Herbs — Glutathione
acetaminophen (paracetamol) overdose contextMinor

GSH-raising strategies (including NAC) are part of the antidote for acetaminophen overdose because GSH depletion is the toxicity mechanism. At normal dosing of either, there is no clinically relevant interaction; in overdose situations, professional emergency care uses IV NAC, not oral sAG.

other GSH-raising supplements (NAC, liposomal glutathione, alpha-lipoic acid, whey protein)Minor

Stacking multiple GSH-raising agents has unclear additive value and runs up cost without obvious benefit. Choose one route based on cost and evidence; don't stack indiscriminately.

warfarinMinor

No documented clinical interaction. The thiol-containing structure is theoretically capable of altering platelet function, but no clinical bleeding events have been reported.

Food sources

Not directly obtained from food — body makes glutathione from amino acid precursors

Amount
N/A
%DV
—

Whey protein concentrate (high cysteine — GSH precursor)

Amount
1 scoop / ~25 g protein (rich cysteine source)
%DV
—

Eggs (cysteine and methionine)

Amount
2 large eggs (~12 g protein, cysteine-rich)
%DV
—

Garlic and onions (sulfur compounds, modest GSH-supporting)

Amount
1 clove garlic / ½ cup chopped onion
%DV
—

Cruciferous vegetables (broccoli, Brussels sprouts — sulforaphane induces GSH synthesis)

Amount
1 cup cooked
%DV
—

Asparagus (modest dietary GSH content)

Amount
1 cup cooked
%DV
—

Spinach (modest dietary GSH content)

Amount
1 cup cooked
%DV
—

Avocado (modest dietary GSH content)

Amount
½ avocado
%DV
—

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Active ingredient stated as 'S-Acetyl-L-Glutathione' or 'S-Acetyl-Glutathione' (with mg per capsule)
Third-party tested (USP, NSF, ConsumerLab) — actual content vs label has been a documented issue
Single-ingredient capsule if you want to track effect specifically attributable to sAG
Stable storage information (some sAG products degrade with moisture/heat exposure)
Reasonable per-capsule dose (100–200 mg) so you're not having to take many capsules to hit study-range
COA (Certificate of Analysis) available for the specific lot

Be skeptical of…

'The only oral form of glutathione that works' — Richie 2015 showed standard oral GSH also raises blood GSH
'10× more bioavailable than other forms' — direct head-to-head human bioavailability trials don't exist
'Reverses aging' / 'master detoxifier' marketing — vague, not evidence-based
'Treats Lyme', 'treats long COVID', 'treats autism' — specific disease-treatment claims aren't validated
'IV-equivalent oral form' — oral bioavailability has a hard ceiling vs IV regardless of formulation
Combination 'detox stacks' bundling sAG + chlorella + cilantro + bentonite at premium prices
Mega-dose products (>500 mg per capsule) — no studied benefit at extreme doses
Topical or transdermal sAG creams — no quality evidence for absorption or benefit

Frequently asked questions

Is acetyl-glutathione better than standard glutathione?⌄

It may have better oral stability, but rigorous comparative bioavailability studies in humans are limited. NAC is often a cost-effective alternative for raising glutathione.

Does it help with detoxification?⌄

Glutathione is central to liver detoxification. Whether supplementation provides meaningful clinical benefit in healthy people is debated.

References by claim

Intracellular glutathione delivery (mechanistic)

Cacciatore et al., 2010 — PMC — Molecules (review) (2010) link

Raising whole-blood glutathione (general)

Richie et al., 2015 — European Journal of Nutrition (2015) link

Allen & Bradley, 2011 — Journal of Alternative and Complementary Medicine (2011) link

Non-alcoholic fatty liver disease (NAFLD)

Buonocore et al., 2016 — Italian Journal of Gastroenterology and Hepatology / Minerva Gastroenterologica (2016) link

Safety

Memorial Sloan Kettering Cancer Center — About Herbs — Glutathione (2024) link

Other references

Glutathione on Wikidata — Wikidata link

Track Acetyl-Glutathione with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·Last reviewed Jun 1, 2026·Evidence current as of Jun 1, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.