Glutathione-precursor supplement combination · Fact sheet
GlyNAC
Also known as Glycine + N-acetylcysteine
GlyNAC combines glycine and N-acetylcysteine as glutathione precursors. Small studies show some metabolic or functional signals, while a larger short trial missed its primary glutathione endpoint. Human longevity benefit is unproven.
What is GlyNAC?
Glutathione synthesis requires glycine and cysteine; NAC supplies a cysteine precursor.
GlyNAC is a combination, not a separate peptide, and products need not reproduce the study formulations or proportions.
Benefits & claims
Interest centers on antioxidant defenses, mitochondrial function and aging-related physical function. Biomarker shifts do not establish lifespan extension.
What the evidence supports
- The smaller study supports further testing of glutathione, metabolic and functional outcomes.
- The larger short study did not meet its primary glutathione endpoint in the full cohort.
- Neither trial establishes longer human life or prevention of age-related disease.
Research areas
- Glutathione status
- Oxidative-stress markers
- Older-adult physical function
Dosage & frequency
Human study contextThe larger short GlyNAC trial reports total combination amounts explicitly; these do not establish an anti-aging prescription.
2022 randomized 114-person GlyNAC trial
Healthy older volunteers, mean age approximately 65 years
- Amount
- Total glycine plus NAC amounts of 2.4, 4.8 or 7.2 g/day in separate groups, in a 1:1 ratio
- Frequency
- Daily for two weeks
- Route studied or labeled
- Oral supplementation
The amount is the total combination, not that amount of each ingredient. The overall primary glutathione endpoint was negative. Longer studies used different designs and cannot be merged into this schedule.
How to read these amounts
An approved regimen belongs to a specific product, indication, and population. A study regimen describes what researchers tested; it does not establish a prescription or a safe self-use protocol. Products, routes, and formulations are not interchangeable. A prescriber uses the full label and individual clinical circumstances.
Personal accounts may describe amounts, schedules and outcomes beyond clinical research. They do not establish a regimen. Read the reported experiences
Formulations, interactions & practical context
- Identity and pharmacology
- Glutathione synthesis requires glycine and cysteine; NAC supplies a cysteine precursor.
Formulation differences
- GlyNAC is a combination, not a separate peptide, and products need not reproduce the study formulations or proportions.
Interactions & precautions
- The reviewed sources do not establish a comprehensive human interaction profile for this exact substance or combination.
What is still unresolved
- Reproducibility in larger longer trials
- Disease prevention and mortality outcomes
- Which baseline deficiencies predict response
Side effects & risks
- Short trials reported tolerability, but cannot establish long-term safety for all doses or populations.
- Combination tolerability and interactions should not be assumed from one ingredient or a biomarker result.
This is a summary of the cited evidence, not a complete product label. A lack of human safety data does not establish safety.
Clinical research
Early human evidenceA 24-person older-adult randomized study reported multiple improvements over 16 weeks. A separate 114-person, two-week trial found no significant primary glutathione increase; its subgroup findings were post hoc.
Studies
24 older adults randomized for 16 weeks; multiple functional and biomarker outcomes.
Two-week study; negative overall primary endpoint and exploratory subgroup.
Eight older adults in an uncontrolled pilot; important design limitations.
Personal experiences
Reports describe what someone noticed. They cannot establish cause, typical results, or how often a side effect happens. Amounts and schedules describe the individual account, not an effective or safe dose. Product identity and strength may be unverified, and missing details are left explicit.
No attributable personal accounts were found in the sources reviewed.
Approval status
GlyNAC is not an FDA-approved anti-aging drug. Dietary-supplement marketing does not establish premarket approval of safety or efficacy.
No FDA-approved product for this entry
Approval covers the labeled product, use and population. A trial phase does not establish success; a stopped program is not ongoing research.
Open questions
- Reproducibility in larger longer trials
- Disease prevention and mortality outcomes
- Which baseline deficiencies predict response
Summary
Neither trial establishes longer human life or prevention of age-related disease.
Sources
Medical evidence and regulatory sources are listed here. Personal reports are linked separately in the experiences section.
- pubmedGlyNAC randomized older-adult study
24 older adults randomized for 16 weeks; multiple functional and biomarker outcomes.
- pubmedGlyNAC 114-person trial
Two-week study; negative overall primary endpoint and exploratory subgroup.
- fdaFDA: what approval means
Dietary supplements are not FDA-approved for safety and effectiveness before marketing.