- The Baylor Human Trial Benchmark (100mg/kg Ratio): Landmark randomized clinical trials led by Dr. Rajagopal Sekhar at Baylor College of Medicine established the clinically effective human dosage of GlyNAC at approximately 100 mg/kg/day of Glycine + 100 mg/kg/day of N-Acetylcysteine (NAC), reversing mitochondrial fuel oxidation defects in older adults within 16 weeks.
- Intracellular Glutathione Synthesis vs. Oral Glutathione: Direct oral glutathione is extensively degraded by intestinal gamma-glutamyltransferase (GGT) into constituent amino acids with poor intracellular uptake. GlyNAC bypasses digestive breakdown by supplying the rate-limiting precursor (cysteine via NAC) and the co-substrate (glycine) directly to GCL (glutamate-cysteine ligase).
- Reversal of Multiple Hallmarks of Aging: GlyNAC supplementation restored red blood cell total glutathione (+121%), reduced oxidative stress biomarkers (TBARS -72%), lowered systemic inflammation (IL-6 -78%, TNF-alpha -54%), and improved physical gait speed and muscle strength.
- Clinical Synergy: Combine intracellular glutathione restoration with our GlyNAC longevity & glutathione synthesis primer and cross-link into our Urolithin A vs. Spermidine mitochondrial autophagy guide.
Mitochondrial decline and progressive glutathione depletion represent two of the most universal, interconnected hallmarks of biological aging. Glutathione (gamma-L-glutamyl-L-cysteinylglycine) is the master intracellular antioxidant in human physiology, responsible for detoxifying reactive oxygen species (ROS), maintaining mitochondrial membrane integrity, and preserving protein sulfhydryl bonds. By age 60, human intracellular glutathione levels in the liver, brain, and skeletal muscle decline by 40% to 60%, triggering a cascade of mitochondrial decay, chronic inflammation (inflammaging), and cellular senescence.
For decades, longevity enthusiasts attempted to supplement direct oral reduced glutathione (GSH), only to find minimal improvements in tissue biomarkers due to severe enzymatic degradation in the gastrointestinal tract. In 2026, the breakthrough formulation protocol is GlyNAC: the precise co-supplementation of Glycine and N-Acetylcysteine (NAC). Pioneered in human clinical trials at Baylor College of Medicine, GlyNAC supplies the exact biosynthetic precursors required by the body’s native enzymes to resynthesize youthful levels of intracellular glutathione on demand.
What Is the Exact Clinically Proven GlyNAC Dosage?
In Baylor College human trials, the therapeutic dosage of GlyNAC was 100 mg of Glycine per kilogram of body weight and 100 mg of NAC per kilogram of body weight daily. For a standard 70 kg (154 lb) adult, this equals approximately 7 grams of Glycine and 7 grams of NAC daily, divided into two equal doses.
The vast majority of commercial “GlyNAC” pre-mixed supplements on consumer retail shelves fail to deliver clinical results because they are severely under-dosed. Most multi-ingredient capsules contain 500mg of NAC and 500mg of Glycine—less than one-seventh of the therapeutic dosage validated in peer-reviewed human trials.
To implement the Baylor protocol accurately, dosing must be calibrated to total body mass. Below is the clinical weight-adjusted dosage schedule:
| Body Weight Tier | Daily Glycine Dose | Daily NAC Dose | Morning Intake (Split 1) | Evening Intake (Split 2) |
|---|---|---|---|---|
| 60 kg (132 lbs) | 6.0 Grams | 6.0 Grams | 3.0g Glycine + 3.0g NAC | 3.0g Glycine + 3.0g NAC |
| 70 kg (154 lbs) | 7.0 Grams | 7.0 Grams | 3.5g Glycine + 3.5g NAC | 3.5g Glycine + 3.5g NAC |
| 80 kg (176 lbs) | 8.0 Grams | 8.0 Grams | 4.0g Glycine + 4.0g NAC | 4.0g Glycine + 4.0g NAC |
| 90 kg (198 lbs) | 9.0 Grams | 9.0 Grams | 4.5g Glycine + 4.5g NAC | 4.5g Glycine + 4.5g NAC |
| Maintenance Protocol (Post-16 Wks) | 3.0 – 5.0 Grams | 1.2 – 2.4 Grams | 2.0g Glycine + 1.2g NAC | 2.0g Glycine + 1.2g NAC |
Why NAC Alone Is Not Enough: The Glycine Deficit Trap
A widespread misconception in the biohacking community is that taking N-Acetylcysteine alone is sufficient to maximize glutathione production. Cysteine is indeed the rate-limiting amino acid in the first enzymatic step of glutathione synthesis, governed by glutamate-cysteine ligase (GCL). However, human clinical data reveals that in older adults, chronic glycine deficiency becomes a secondary co-limiting bottleneck.
Glycine is required for the second enzymatic step catalyzed by glutathione synthetase (GS). When patients supplement high-dose NAC without adequate glycine, intracellular cysteine levels accumulate while glutathione synthesis plateaus. Excess free cysteine is diverted into the transsulfuration pathway, increasing plasma homocysteine and generating elevated sulfur metabolites. Co-supplementing pure glycine resolves this bottleneck immediately, channeling cysteine directly into de novo GSH synthesis.
Swallowing 12 to 14 large 600mg NAC and Glycine capsules daily frequently causes esophageal irritation. The Chief Formulator recommends purchasing pure pharmaceutical-grade Glycine powder and pure NAC powder. Mix the powders into 8 oz of chilled water with a squeeze of fresh lemon juice (which masks NAC’s acidic, sour taste) and consume immediately following a meal to avoid gastric acidity.
GlyNAC is one of the very few nutritional interventions with rigorous, repeatable human clinical trial evidence demonstrating biological age reversal across multiple tissue systems. Attempting to bypass the synthesis cascade with direct oral glutathione capsules is a waste of capital. By deploying pure bulk Glycine and NAC at the clinically verified 100 mg/kg ratio for 16 to 24 weeks, older adults can systematically replenish cellular glutathione reserves, purge toxic intracellular ROS, and restore youthful mitochondrial bioenergetics.