GlyNAC (Glycine + N-Acetyl Cysteine)

Combination of glycine and N-acetyl cysteine that serves as the rate-limiting precursor pair for glutathione (GSH) synthesis. Restores intracellular glutathione levels that decline with aging, reducing oxidative stress, mitochondrial dysfunction, and genomic damage. Clinical trials in older adults demonstrate improvements in mitochondrial fatty acid oxidation, insulin resistance, inflammation, endothelial function, body composition, muscle strength, and multiple hallmarks of aging simultaneously.

Half-life

~6 hours (combined effective half-life, NAC ~5.6hr, glycine ~4hr)

Bioavailability

NAC: 6-10% (oral), Glycine: ~30% (oral, amino acid transporter-mediated)

Route

oral

Evidence tier

T2 — Single-RCT or mechanistic

Optimization pillars

anti-aging · cellular-health · recovery

References

4 peer-reviewed

Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative

1.2 mmol/kg/day each (glycine ~100mg/kg, NAC ~133mg/kg)

Standard RCT dose

moderate

1.33 mmol/kg glycine + 0.81 mmol/kg NAC per day

Sekhar lab optimized protocol

aggressive

3 g glycine + 1.8g NAC twice daily

Approximate 80kg adult dosing from RCT

Monitoring

hs-crp
fasting-glucose
hba1c
fasting-insulin
homa-ir
lipid-panel
alt
ast
homocysteine
creatinine

Contraindications

active-asthma-nac-sensitivity
gastric-ulcer-active
concurrent-nitroglycerin
pregnancy

References

PMID:33818530Glycine and N-acetylcysteine supplementation in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, physical function, and aging hallmarks — J Gerontol A Biol Sci Med Sci, 2021
PMID:34542076Supplementing glycine and N-acetylcysteine (GlyNAC) in older adults improves oxidative stress, mitochondrial dysfunction, body composition, strength, and cognition — Clin Transl Med, 2021
PMID:36383641GlyNAC supplementation in older adults: a randomized clinical trial — J Gerontol A Biol Sci Med Sci, 2023
PMID:35468716Glutathione deficiency in aging and its correction with GlyNAC — Nutrients, 2022

Notes

GlyNAC is the most underrated longevity intervention in the current landscape. Dr. Rajagopal Sekhar at Baylor published the randomized controlled trial data showing that supplementing glycine and NAC in older adults corrected glutathione deficiency and improved oxidative stress, mitochondrial function, inflammation, insulin resistance, endothelial function, body composition, bone density, gait speed, and cognitive function simultaneously. That is not one biomarker moving. That is multiple hallmarks of aging reversing in a 16-week window. Two amino acids. Combined cost under $30/month. The reason nobody talks about it is the same reason nobody markets creatine as hard as they should — the profit margin on commodity amino acids does not fund influencer campaigns.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

See GlyNAC (Glycine + N-Acetyl Cysteine) in a protocol matched to you