This revision is from 2026/02/26 07:17. You can Restore it.
N-acetylcysteine (NAC) and Glycine are non-essential amino acids that have demonstrated life-extension, health-maintenance, and redox-restorative properties, particularly in aging populations. The combined supplementation of NAC and glycine is commonly referred to as GlyNAC (or NAC-G).
Human aging is associated with a progressive decline in glutathione (GSH) synthesis, driven primarily by reduced availability of cysteine and glycine, impaired enzymatic flux, and increased oxidative demand. Aging, therapeutic restoration of glutathione levels generally cannot be achieved through diet alone.
Reduced Precursor Availability: Low levels of cellular cysteine and glycine.
Impaired Enzymatic Flux: Slower conversion rates by the enzymes responsible for synthesis.
High Oxidative Demand: Increased "free radical" damage that depletes GSH faster than it can be replaced.
(With aging) therapeutic doses may not be applicable with diet.
Deep Research for Anti-Aging Dosage: 100~mg/kg NAC, 100~mg/kg Glycine, 8 grams NAC per day + 8 grams glycine per day (80kg person) with a 6.5 hour half life, twice or 3 times a day. 4g x 2 times a day to meet 8g. Total GlyNAC intake: ~16 g/day
N-Acetyl Cysteine Ethyl Ester - Higher Bioavailability, 1 g NACET ≈ 6–10 g NAC (theoretical tissue effect)
Achieving gram-level intakes would require impractical and physiologically disruptive food volumes.
Glycine is found in...
Legumes, such as soybeans and kidney beans
Spinach and kale
Cysteine NOT N-AcetylCysteine (NAC) is found in...
Whole grains, such as oats and wheat
Legumes, such as lentils and chickpeas
Garlic and onions
To reach ~8 g glycine/day:
Kidney beans: ~2.5 kg cooked
Lentils: ~3 kg cooked
Spinach: ~9 kg cooked
To equal ~8 g NAC-derived cysteine:
Lentils: ~8 kg cooked
Chickpeas: ~9 kg cooked
Oats (dry): ~6 kg
Pumpkin seeds: ~3 kg
Three precursor substances that are needed for the synthesis of glutathione in the body:
Cysteine: Cysteine is an amino acid that is a key building block of glutathione. It is often the limiting factor in the production of glutathione because it is not always readily available in sufficient quantities. Rate-limiting substrate.
Glutamic acid: Glutamic acid is another amino acid that is involved in the synthesis of glutathione. It helps to create the backbone of the glutathione molecule.
Glycine: Glycine is the third and final amino acid involved in the synthesis of glutathione. It is used to form the peptide bonds that link the three amino acids together to create the glutathione molecule. Final conjugation step.
In addition to these three precursor substances, several enzymes are also required to convert them into glutathione. These enzymes include gamma-glutamylcysteine synthetase, glutathione synthetase, and glutathione reductase.
An ideal formula for a supplement that provides all the necessary precursors and enzymes for the production and restoration of glutathione levels in the body would include the following:
N-acetylcysteine (NAC): NAC is a precursor to cysteine, which is a key building block of glutathione. It is also a potent antioxidant that helps to support glutathione levels in the body.
Alpha-lipoic acid (ALA): ALA is a co-factor for several enzymes involved in glutathione production, including gamma-glutamylcysteine synthetase and glutathione synthetase. It also has antioxidant properties that help to support glutathione levels in the body.
L-glutamine: Glutamine is another precursor to glutathione that helps to support its production in the body.
Selenium: Selenium is a mineral that is required for the activity of glutathione peroxidase, an enzyme that helps to regenerate glutathione in the body.
Vitamin C: Vitamin C is an antioxidant that helps to regenerate glutathione in the body by reducing oxidized glutathione back to its active form.
Vitamin E: Vitamin E is another antioxidant that works synergistically with vitamin C to regenerate glutathione in the body.
Zinc: Zinc is a co-factor for glutathione synthetase, an enzyme involved in glutathione production.
Magnesium: Magnesium is required for the activity of glutathione reductase, an enzyme that helps to regenerate glutathione in the body.
By combining these ingredients in the right doses, it may be possible to create a supplement that provides the body with all the necessary precursors and enzymes to support glutathione production and restoration.
Food Sources...
N-acetylcysteine (NAC): NAC is not found in significant amounts in food, but its precursor, cysteine, can be found in plant-based sources such as legumes (lentils, chickpeas, black beans), nuts and seeds (pistachios, sunflower seeds, pumpkin seeds), and whole grains (oats, quinoa).
Alpha-lipoic acid (ALA): ALA can be found in small amounts in certain plant-based sources such as spinach, broccoli, and tomatoes.
L-glutamine: Glutamine is found in plant-based sources such as beans, lentils, nuts and seeds (almonds, sunflower seeds, pumpkin seeds), and whole grains (brown rice, oats, quinoa).
Selenium: Selenium can be found in plant-based sources such as Brazil nuts, chia seeds, sunflower seeds, and whole grains (brown rice, oats, quinoa).
Vitamin C: Vitamin C is found in a wide range of plant-based sources including citrus fruits (oranges, lemons), berries (strawberries, raspberries), kiwifruit, papaya, mango, pineapple, guava, broccoli, spinach, and bell peppers.
Vitamin E: Vitamin E is found in plant-based sources such as nuts and seeds (almonds, sunflower seeds, pumpkin seeds), leafy greens (spinach, kale, Swiss chard), and avocados.
Zinc: Zinc can be found in plant-based sources such as legumes (lentils, chickpeas, black beans), nuts and seeds (cashews, pumpkin seeds, sesame seeds), and whole grains (brown rice, quinoa).
Magnesium: Magnesium is found in plant-based sources such as leafy greens (spinach, kale, Swiss chard), nuts and seeds (almonds, cashews, pumpkin seeds), whole grains (brown rice, oats, quinoa), and legumes (lentils, black beans, chickpeas).
The high doses of GlyNAC (approximately 8 g daily) used in therapeutic trials for older adults are essentially a "high-pressure" strategy to overcome a significantly degraded enzymatic "engine." In younger individuals, the molecular machinery is efficient enough to maintain optimal glutathione (GSH) levels with much lower precursor availability.
What is "Broken" in the Aging Machine?
Molecular machinery of aging identifies three primary failures that necessitate high-dose GlyNAC
Nrf2 Pathway Blunting: The "master switch" for antioxidant defense, Nrf2, becomes less responsive with age. Under youthful conditions, Nrf2 translocates to the nucleus to trigger the expression of GCL and GS (the enzymes that synthesize GSH). In aging, this signaling is repressed, meaning the "orders" for enzyme production are drastically reduced.
Bach1 Repression: Bach1 is a protein that acts as a competitive repressor of Nrf2. In aging and neurodegenerative states, Bach1 accumulates and occupies the antioxidant response element (ARE) sites on DNA, actively blocking Nrf2 from turning on GSH synthesis genes.
The Bach1-CHAC1 Axis: Bach1 not only blocks synthesis but also activates CHAC1, an enzyme that specifically catalyzes the hydrolysis (degradation) of GSH. This creates a "leaky bucket" scenario where the older machine is making less GSH while simultaneously breaking it down faster.
Enzymatic Uncoupling: The rate-limiting enzyme, glutamate-cysteine ligase (GCL), consists of two subunits (GCLC and GCLM). In aging tissues, the expression of these subunits becomes "uncoupled," leading to an inefficient enzyme with a lower affinity for its substrates, requiring much higher concentrations of cysteine to function effectively.
Therapeutic Targets to Reduce GlyNAC Requirements
By targeting the regulatory machinery rather than just providing the "fuel," it is theoretically possible to reduce the required GlyNAC dosage:
Bach1 Inhibitors: Inhibiting Bach1 de-represses the Nrf2 pathway. This allows the cell to resume its youthful genetic program for GSH synthesis and suppresses the CHAC1-mediated degradation of GSH.
Nrf2 Activators (e.g., Sulforaphane): These compounds (found in broccoli sprouts and grape skins) stimulate Nrf2 translocation. Studies show that combining Nrf2 activators with precursors can have an additive effect, potentially allowing for lower doses of GlyNAC to achieve the same restorative effect. Compounds that release Nrf2 from its inhibitor Keap1 or enhance its stability upregulate GSH synthesis enzymes. Examples include sulforaphane (found in broccoli sprouts; typical human dose ~50–100 µmol/day) and lipoic acid (LA) (600–1200 mg/day). In old rats, LA injections restored nuclear Nrf2 and raised GCL protein/activity within 24-48 h. Dietary phytochemicals like curcumin or dimethyl fumarate (DMF) similarly activate Nrf2. Clinical doses range from ~500-1000 mg/day of curcumin or 20-60 mg/day of standardized sulforaphane. These agents also induce other antioxidant enzymes, creating a broad boost to redox resilience.
Alpha-Lipoic Acid (ALA): ALA acts as a transcription inducer that enhances the activity of GCL and promotes the cellular uptake of cysteine, effectively making the "GSH factory" more efficient. Alpha-lipoic acid (600 mg/day) scavenges free radicals and, as a disulfide, regenerates other antioxidants (vitamins C/E and GSH). ALA also appears to upregulate GSH synthesis genes (likely via Nrf2) and has an excellent safety record. Emerging drugs like bardoxolone methyl (CDDO-Me) or sulforaphane mimetics strongly induce antioxidant genes but currently lack clear long-term safety data in healthy aging.
ALA works best pulsed, not chronic high dose.
150–200 mg R-ALA
3–5 days per week
morning, fasted
Why pulsing matters:
avoids reductive stress
preserves Nrf2 sensitivity
prevents insulin over-sensitization
Doctor’s Best Stabilized R‑Lipoic Acid w/ BioEnhanced Na‑RALA
NAD+ Restoration: The recycling of oxidized glutathione (GSSG) back into its active GSH form requires NADPH, which is dependent on healthy NAD+ levels. Repleting NAD+ can improve the "recycling" efficiency of the machine, reducing the burden on the de novo synthesis pathway supported by GlyNAC. NAD⁺ Precursors: Supplementation with nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN) (typical doses ~250–500 mg/day) restores cellular NAD+ pools and indirectly elevates GSH. Recent work in neural cells showed that NAD⁺ treatment increases the GSH/GSSG ratio and upregulates GCL mRNA/protein via an NAD⁺→SIRT2→ERK→Nrf2 pathway. In practice, niacin (500 mg/day) or NR/NMN can hence reactivate GSH production through sirtuins and Nrf2. NAD+ also supports NADPH generation (via NADK and PPP crosstalk), further aiding GSH reductase.
If these regulatory defects are addressed—specifically by inhibiting Bach1 and activating Nrf2—the body's requirement for GlyNAC may shift from "therapeutic loading" (8 g) back to "maintenance" levels (600-1,200 mg daily).
How to Improve Bioavailability (Even With Regular NAC)
If using standard NAC, here is how to optimize:
✔ Take on empty stomach
Food (especially protein) competes for transport.
✔ Split dosing
Instead of 3 g once:
1 g × 3 times daily
Reduces saturation + GI distress.
✔ Combine with Glycine
Improves downstream GSH synthesis efficiency.
✔ Add Nrf2 activators
Sulforaphane, ALA, exercise
→ increases enzyme demand → better utilization of delivered cysteine.
✔ Support transsulfuration
Ensure adequate:
B6
B12
Folate
Prevents cysteine diversion to homocysteine cycling.
IMMORTALITY