GlyNAC: The Two-Ingredient Supplement That Reverses Multiple Signs of Aging
A clinical trial showed that combining glycine and NAC restored glutathione, improved mitochondria, reduced inflammation, and reversed aging hallmarks in older adults.
What if the most effective anti-aging supplement wasn't exotic or expensive — but a combination of two amino acids you've never thought about?
The Glutathione Problem
Your body has a master antioxidant called glutathione (GSH). It's in every cell, and it does the heavy lifting against oxidative stress — the cellular damage that drives aging, inflammation, and disease.
Here's the problem: as you age, your glutathione levels drop. And when they drop, bad things cascade:
- Oxidative stress increases, damaging DNA and proteins
- Mitochondria start misfiring — your cells produce energy less efficiently
- Chronic inflammation creeps up (the "inflammaging" that underlies most age-related disease)
- Insulin resistance develops
- Physical strength and cognitive function decline
You might think: "I'll just take a glutathione supplement." But here's the catch — oral glutathione is poorly absorbed. Your gut breaks it down before it reaches your cells. It's like trying to mail a completed puzzle; it arrives in pieces.
The GlyNAC Solution
Researchers at Baylor College of Medicine, led by Dr. Rajagopal Sekhar, took a different approach. Instead of supplementing glutathione directly, they asked: what if we give the body the raw materials to make its own?
Glutathione is built from three amino acids: glutamate, cysteine, and glycine. Glutamate is abundant in most diets. But glycine and cysteine become deficient with aging.
So they created GlyNAC: a combination of:
- Glycine — the simplest amino acid, crucial for collagen, sleep, and detoxification
- N-Acetylcysteine (NAC) — a stable form of cysteine, readily available as a supplement
Both are cheap, widely available, and well-tolerated. The idea was elegant: feed the body the missing building blocks and let it restore its own glutathione production.
The Clinical Trial
In a randomized, double-blind, placebo-controlled trial (the gold standard of medical research), 24 older adults (aged 61–80) were split into two groups: one received GlyNAC, the other received a placebo. Twelve young adults also participated as a baseline comparison.
The GlyNAC group supplemented for 16 weeks. The results, published in the Journal of Gerontology, were remarkable:
What Improved
| Measure | Result |
|---|---|
| 🛡️ Glutathione levels | Restored to young-adult levels |
| ⚡ Mitochondrial function | Significantly improved |
| 🔥 Oxidative stress | Dramatically reduced |
| 🩸 Inflammation markers | Lowered |
| 💪 Muscle strength | Improved |
| 🚶 Gait speed | Faster |
| 🧠 Cognition | Improved |
| 📏 Waist circumference | Reduced |
| 🫀 Insulin resistance | Improved |
| 🧬 Aging hallmarks | Multiple markers corrected |
The placebo group? No changes.
What makes this study particularly compelling is the breadth of improvements. This wasn't a supplement that helped one thing — it improved oxidative stress, mitochondrial function, inflammation, metabolism, physical function, and cognitive performance simultaneously.
Why Glycine Deserves More Attention
While NAC gets most of the supplement industry's spotlight, glycine is arguably the unsung hero:
- Collagen production: Glycine is the most abundant amino acid in collagen (every third amino acid in the collagen chain is glycine). Your skin, joints, and connective tissues depend on it.
- Sleep quality: Glycine taken before bed has been shown to improve sleep quality and reduce daytime sleepiness.
- Neuroprotection: Glycine acts as an inhibitory neurotransmitter in the brain and spinal cord.
- Methylation: Glycine is consumed in large quantities by methylation reactions — a fundamental process for gene expression and detoxification.
- Anti-inflammatory: Glycine suppresses inflammatory cytokines.
Modern diets are likely glycine-deficient. Our ancestors ate the whole animal — skin, bones, tendons, cartilage — all rich in glycine. Today, most people eat only muscle meat, which is high in methionine but low in glycine. This imbalance may itself accelerate aging.
What About GABA?
GABA (gamma-aminobutyric acid) is the brain's main inhibitory neurotransmitter — it calms neural activity. While it doesn't have the same aging-reversal evidence as GlyNAC, it shares some interesting properties:
- Sleep and relaxation: GABA supplements may improve sleep quality and reduce anxiety
- Growth hormone: Some studies suggest GABA supplementation increases growth hormone secretion
- Synergy with glycine: Both are inhibitory neurotransmitters; glycine actually activates GABA receptors in some brain regions
GABA's direct longevity evidence is weaker than GlyNAC's, but as a sleep and stress-management tool, it supports the broader picture: quality sleep and reduced stress are themselves longevity interventions.
What This Means For You
GlyNAC supplementation is one of the most evidence-backed, accessible longevity interventions available today. Here's the practical breakdown:
- Glycine: 1–3g per day (or more — it's very safe). Can also be obtained from bone broth, collagen supplements, and gelatin.
- NAC (N-Acetylcysteine): 600–1200mg per day. Widely available as a supplement.
- Take them together — the combination is what drives glutathione restoration.
- Consistency matters — the clinical trial showed results building over 16 weeks.
- Bone broth is a natural source of glycine — a cup a day provides meaningful amounts.
These are not exotic compounds. They're cheap, available at any supplement store, and have decades of safety data. The GlyNAC trial is one of the few human clinical trials showing simultaneous improvement across multiple hallmarks of aging.
Always consult your doctor before starting any new supplement regimen, especially if you take medications.
🛒 Recommended Products
Affiliate Disclosure: Links below may earn us a commission at no extra cost to you. We only recommend products backed by the evidence discussed above.
GlyNAC Supplement (Glycine + NAC Combo) — Look for a combined formula providing both glycine and NAC in clinical doses for convenience.
Glycine Powder — Pure glycine powder is affordable and easy to mix into water or tea. Aim for 1–3g per day.
NAC Capsules (N-Acetylcysteine) — 600–1200mg per day in capsule form. Look for reputable brands with third-party testing.
Sources
- Kumar P, et al. (2023). "Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial." J Gerontol A Biol Sci Med Sci. 78(1):75-89. PMID: 35975308
- Kumar P, et al. (2021). "Glycine and N-acetylcysteine (GlyNAC) supplementation in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, insulin resistance, endothelial dysfunction, genotoxicity, muscle strength, and cognition: Results of a pilot clinical trial." Clin Transl Med. 11(3):e372. PMID: 33783984
- ClinicalTrials.gov: NCT01870193