Evidence-based·Last reviewed May 30, 2026·How we grade evidence

Gamma-Glutamylcysteine

SpecialtyDipeptide

Useful mainly for people specifically aiming to raise blood/cellular glutathione.

Quick decision guide

May help most

People specifically aiming to raise blood/cellular glutathione

Common dosing range

100–400 mg/day; ~200 mg common

When to expect effects

Hours to days for glutathione rise; clinical effects unproven

Watch out for

Evidence is biomarker-level — raising glutathione has not been shown to improve health outcomes

What is it

Gamma-glutamylcysteine (GGC) is the immediate dipeptide precursor of glutathione, the body's main intracellular antioxidant. It is sold to raise glutathione levels, bypassing the rate-limiting synthesis step that normally controls glutathione production.

Is it worth it for you?

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

Worth considering if…

Your explicit goal is to raise glutathione and you accept that as a biomarker only
You want a direct glutathione precursor and tolerate it well

Probably skip if…

You expect a defined clinical benefit (immunity, detox, disease prevention)
You want strong human outcome evidence
You are content with cheaper precursors like NAC unless you specifically prefer GGC

Evidence at a glance

raising glutathione levels

Limited Evidence
Effect
Measurable rise in blood glutathione
Best fit
Adults wanting to increase glutathione status
Time
Hours to days

Evidence for 1 use

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

raising glutathione levels

Biomarker support
Limited Evidence

Small human studies indicate that oral gamma-glutamylcysteine can raise blood (lymphocyte) glutathione concentrations, consistent with its role as the direct precursor. This is a biomarker change only; no trials show that the resulting rise translates into improved immunity, disease prevention, or other clinical endpoints.

Effect size
Measurable rise in blood glutathione
Time to effect
Hours to days
Best fit
Adults wanting to increase glutathione status
Less likely
Anyone seeking a proven clinical outcome

Bottom line: GGC can raise glutathione levels, but a higher glutathione reading is not itself a proven health benefit.

SourceZarka et al., 2017 — PMCQuintana-Cabrera et al., 2013 — PubMed

How to take it

1. Typical dose
100–400 mg/day, with ~200 mg a common choice
2. Timing
Any time of day
3. With food
Either; no clear food requirement
4. How long to try
A few weeks is enough to see whether a glutathione marker moves, if measured

What to track

Blood glutathione if you can measure it
GI tolerability

Safety

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

Common side effects

Generally well tolerated in short studiesOccasional mild GI upset

Who should avoid it

  • People wanting a treatment with proven clinical efficacy

Pregnancy & breastfeeding

No safety data; avoid unless advised by a clinician.

Choosing a product

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

Look for…

States gamma-glutamylcysteine content per dose
Third-party tested for identity and purity

Be skeptical of…

“Detoxifies the body”
“Boosts immunity”
“Master antioxidant cure”

References by claim

raising glutathione levels

Zarka et al., 2017 — PMC (2017) link

Quintana-Cabrera et al., 2013 — PubMed (2013) link

Track Gamma-Glutamylcysteine with Pilora

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

Coming to App Store
Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 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.