N-Acetyl-L-Cysteine (NAC)

N-Acetyl-L-Cysteine (NAC / Purity ≥98.5%-101.0% USP/EP / Vegan Fermentation Derived) | Gold Standard Thiol Donor for Intracellular Glutathione Synthesis, Mucolytic Clearance & Longevity

1. Product Overview & Value Proposition

N-Acetyl-L-Cysteine (NAC, (2R)-2-acetamido-3-sulfanylpropanoic acid, N-乙酰-L-半胱氨酸 / 乙酰半胱氨酸), produced via pharmaceutical-grade microbial fermentation and clean catalytic acetylation, represents the foundational clinical active in intracellular redox biology, clinical toxicology, pulmonary medicine, and cellular longevity geroscience. While unmodified L-cysteine is notoriously unstable in oral formulation—rapidly oxidizing into insoluble L-cystine or degrading during first-pass gastrointestinal transit—the addition of an acetyl moiety (-COCH₃) to the nitrogen terminal creates a stable, bioavailable molecule. N-Acetyl-L-Cysteine powder efficiently crosses the intestinal epithelium and cellular membranes intact. Once inside the cytoplasm, cellular acylase enzymes hydrolyze the acetyl bond, liberating biologically active L-cysteine directly into the cytosol, where it serves as the essential, rate-limiting building block for the synthesis of reduced glutathione (GSH).

In human biochemistry and respiratory pharmacology, NAC exhibits multifaceted clinical mechanisms:

• Rate-Limiting Substrate for Glutathione Resynthesis: Glutathione (tripeptide γ-L-glutamyl-L-cysteinylglycine) is the body’s primary endogenous antioxidant, protecting mitochondrial DNA, detoxifying xenobiotics, and recycling oxidized Vitamins C and E. Intracellular cysteine concentrations represent the sole rate-limiting checkpoint in glutathione production. NAC directly fuels glutamate-cysteine ligase (GCL), replenishing cellular GSH reserves that decline during aging, metabolic stress, and viral infections.
• Clinical Mucolytic Action via Disulfide Cleavage: The free sulfhydryl (-SH) group of NAC directly targets mucoproteins. It acts as a reducing agent that physically breaks the intra- and intermolecular disulfide bonds of high-molecular-weight mucopolysaccharide networks in bronchial mucus, lowering sputum viscosity, clearing airway blockages, and easing breathing in chronic bronchitis, COPD, and acute respiratory infections.
• Hepatic Phase II Detoxification: As the globally recognized clinical antidote for acetaminophen (paracetamol) hepatotoxicity, NAC provides sulfhydryl groups that directly bind to and neutralize toxic N-acetyl-p-benzoquinone imine (NAPQI) metabolites, preventing hepatic centrilobular necrosis and restoring liver enzyme balance (ALT/AST).
• Glutamate Neurotransmission & Cystine-Glutamate Antiporter (System xc⁻): In central neurobiology, extracellular NAC dimerizes into cystine, activating the astrocyte cystine-glutamate antiporter (system xc⁻). This mechanism pumps cystine into glial cells while releasing glutamate into the extrasynaptic space, stimulating inhibitory metabotropic glutamate receptors (mGluR2/3) to downregulate hyperactive neuronal glutamate release—supporting clinical protocols for compulsive behaviors, cognitive clarity, and mood stability.
• The Emerging “GlyNAC” Longevity Synergy: Landmark human clinical trials from Baylor College of Medicine prove that co-supplementing NAC alongside pure Glycine (the “GlyNAC” protocol) corrects mitochondrial fuel oxidation, reverses age-associated glutathione deficiency, reduces chronic systemic inflammation, improves physical gait speed, and lowers cognitive oxidative markers in aging adults.

As an established bulk N-Acetyl-L-Cysteine manufacturer and direct active ingredient supplier, our processing facilities operate closed-loop non-GMO fermentation suites, high-yield catalytic acetylation lines, and vacuum crystallization units complying with cGMP, USP, EP, and ChP standards. To empower agile dietary supplement brands, sports nutrition formulators, and contract manufacturing organizations (CMOs), we pair uncompromising analytical quality with flexible commercial terms: accessible low MOQ procurement for benchtop pilot trials, multi-ingredient shipment consolidation across our longevity vitamins (L-5-MTHF-Ca, β-NMN), functional mushrooms (Cordyceps, Lion’s Mane), and antioxidant carotenoids, and dedicated on-the-ground China-wide raw material sourcing assistance tailored to your exact manufacturing roadmap.

2. Product Specifications (Analytical Quality)

3. Functional Applications (Mechanism of Action)

Deploying pharmaceutical-grade N-Acetyl-L-Cysteine across cellular longevity supplements, respiratory formulations, and hepatic detoxification products provides scientifically verified biological mechanisms:

• Direct De Novo Synthesis of Reduced Glutathione (GSH): In human cellular metabolism, glutathione (GSH) is synthesized in two adenosine triphosphate (ATP)-dependent enzymatic steps: first, glutamate-cysteine ligase (GCL) couples glutamate with cysteine; second, glutathione synthetase adds glycine. Cysteine is present in dietary pools in the lowest concentrations, serving as the sole rate-limiting bottleneck. NAC readily passes through the intestinal brush border and enters cells intact. Intracellular deacetylation liberates free L-cysteine, driving high-affinity enzymatic resynthesis of GSH to elevate mitochondrial redox defenses and protect cellular proteins against oxidative carbonylation.
• Enzymatic Disulfide Mucolysis & Airway Clearance: Bronchial and pulmonary mucus in respiratory inflammation is thickened by extensive cross-linking of disulfide (-S-S-) bonds between mucin glycoprotein chains. The reactive free sulfhydryl (-SH) group of NAC engages in direct thiol-disulfide exchange reactions, reducing and breaking disulfide cross-links into smaller, unlinked sulfhydryl fragments. This liquefies dense, viscous mucus, lowers sputum tenacity, accelerates mucociliary clearance, and eases dyspnea in COPD, cystic fibrosis, and viral respiratory syndromes.
• Hepatic Xenobiotic Neutralization & Phase II Conjugation: In hepatic tissue, toxic electrophilic metabolites (such as paracetamol-derived NAPQI, alcohol-induced acetaldehyde, and environmental heavy metals) deplete endogenous liver glutathione, leading to hepatocellular membrane rupture. NAC acts as an emergency sulfhydryl donor: it directly conjugates with NAPQI to form non-toxic mercapturic acid conjugates excreted in urine, while fueling the hepatic Phase II glutathione S-transferase (GST) system to accelerate whole-body detoxification.
• Central Synaptic Glutamate Regulation via System xc⁻: Hyperactive glutamate signaling and excitotoxicity are implicated in neurodegenerative cognitive decline and addiction. NAC crosses the blood-brain barrier and dimerizes into cystine, activating the glial cystine-glutamate antiporter (system xc⁻). This imports cystine into astrocytes while releasing glutamate into the extrasynaptic space, which binds to inhibitory presynaptic metabotropic glutamate receptors (mGluR2/3). This feedback loop downregulates excessive synaptic glutamate release, mitigating neuro-inflammation and supporting emotional stability.
• Mitochondrial Bioenergetics & The “GlyNAC” Longevity Cascade: With advancing age, declining glutathione levels lead to chronic mitochondrial fuel combustion dysfunction and elevated lipid peroxides. Clinical trials confirm that combining NAC with Glycine (GlyNAC) provides both essential precursors required to restore intracellular glutathione synthesis, significantly lowering systemic inflammation markers (IL-6, TNF-α, CRP), reducing insulin resistance, improving mitochondrial ATP output, and restoring muscle strength and cognitive processing speed.
• Sulfhydryl Balance & Non-Clumping DC Tableting: Pure NAC is naturally hydroscopic and can display a characteristic sulfur odor if exposed to ambient moisture. Our low-odor DC-95 granular grade utilizes specialized fluid-bed granulation with clean pharmaceutical binders, eliminating the need for wet granulation in CMO plants and enabling direct tableting into high-hardness effervescent or film-coated tablets without mechanical sticking or sulfur volatilization.

4. Formulation Combinations & Trending Market Applications

Capitalize on the expanding cellular longevity, respiratory defense, liver recovery, and functional wellness markets by formulating with our versatile N-Acetyl-L-Cysteine portfolio:

• The Master Clinical “GlyNAC Longevity & Mitochondrial Fuel” Matrix: Our N-Acetyl-L-Cysteine (USP/EP Grade, 600 mg – 1,200 mg) + Pure Glycine (USP Grade, 600 mg – 1,200 mg, establishing the clinical 1:1 GlyNAC molar ratio) + Alpha-Lipoic Acid (ALA 300 mg) + L-Selenomethionine (100 μg elemental Se) + Calcium L-5-Methyltetrahydrofolate (400 μg DFE). Modeled after Baylor College of Medicine human clinical trials: GlyNAC restores intracellular glutathione synthesis, ALA recycles oxidized glutathione back to its reduced state, and Selenium acts as the essential cofactor for glutathione peroxidase (GPx), reversing mitochondrial oxidative decline.
• The “Broncho-Pulmonary & Respiratory Airway” Effervescent Tablet: Our NAC (DC-95 Granular, 600 mg delivering 570 mg active NAC) + Quercetin Phytosome (250 mg) + Bromelain (2,400 GDU/g, 100 mg) + Zinc Bisglycinate (15 mg elemental Zn) + Vitamin C (as Ascorbic Acid, 500 mg). A delicious, fast-dissolving effervescent tablet designed to cleave bronchial mucoprotein disulfide bonds, downregulate pulmonary inflammatory cytokines, and fortify respiratory barrier immunity against seasonal airborne pathogens.
• The “Hepatic Defense & Hangover Recovery” Packet: Our N-Acetyl-L-Cysteine (≥99.0%, 500 mg) + Dihydromyricetin (DHM ≥98%, 300 mg) + Milk Thistle Extract (Silymarin 80%, 200 mg) + Vitamin B-Complex (B1, B6, B12) + Electrolyte Matrix (Sodium, Potassium, Magnesium Citrate). An advanced metabolic recovery formula engineered to accelerate toxic acetaldehyde clearance, replenish hepatic glutathione pools, protect liver parenchymal cells, and alleviate morning-after physiological fatigue.
• The Trending “Detox & Focus” Morning Mushroom Coffee Stack: Our Low-Odor N-Acetyl-L-Cysteine (300 mg) + Cordyceps Militaris Extract (Cordycepin 1%, 300 mg) + Lion’s Mane Mushroom Extract (Beta-Glucan 30%, 300 mg) + Micro-Ground Arabica Coffee (yielding ~60 mg native caffeine) + L-Theanine (100 mg). An elite functional morning brew engineered to support systemic glutathione production, optimize cellular oxygen utilization via Cordyceps, enhance neuro-cognitive focus, and provide smooth, jitter-free adaptogenic vitality throughout the workday.

5. Why Choose Us As Your Long-Term Active Ingredient Partner?

• Flexible Low MOQ Policy: Mitigate product launch risk. As an agile low MOQ N-Acetyl-L-Cysteine bulk supplier, our orders start as low as 1 kg for ultra-pure USP/EP crystalline powders and DC-95 direct compression granules, scaling smoothly up to recurring multi-ton commercial container contracts.
• 100% Vegan Microbial Fermentation (Zero Human Hair Origin): Historically, commercial L-cysteine was extracted from poultry feathers or human hair using harsh hydrochloric acid hydrolysis. Our NAC is derived exclusively from the clean bio-fermentation of non-GMO corn/glucose substrates, guaranteeing 100% vegan provenance, zero animal contamination (BSE/TSE-free), and full Kosher and Halal compliance.
• Multi-Product Portfolio Consolidation: Streamline your supply chain by sourcing your complete longevity and detox suite (N-Acetyl-L-Cysteine, Glycine, Alpha-Lipoic Acid, CoQ10, β-NMN, L-5-MTHF-Ca), functional mushrooms (Cordyceps, Lion’s Mane, Reishi), and botanical extracts under a single, cost-effective freight shipment to reduce customs overhead and landed freight costs.
• Value-Added China Sourcing Service: In addition to our dedicated bio-fermentation facilities, catalytic acetylation plants, and industrial crystallization suites, our on-the-ground technical team audits upstream glucose feedstocks, validates multi-compendial pharmacopeial paperwork, and procures specialized functional ingredients across China tailored to your exact manufacturing roadmap.

6. Quality & Supply Chain Assurance

• Precision Enzymatic Fermentation & Clean Acetylation: L-cysteine is biosynthesized via closed-loop microbial fermentation of non-GMO plant sugars. Purified cysteine then undergoes controlled catalytic acetylation with high-purity acetic anhydride in aqueous phase, followed by multi-stage membrane filtration, activated carbon decolorization, and low-temperature vacuum crystallization.
• Multi-Compendial Pharmacopeial Compliance: Every commercial batch is produced in cGMP-certified facilities and tested to meet or exceed the rigorous analytical monographs of the United States Pharmacopeia (USP), European Pharmacopoeia (Ph. Eur.), British Pharmacopoeia (BP), and Chinese Pharmacopoeia (ChP).
• Strict Free Thiol & Dimer Monitoring: Tested via potentiometric titration and reversed-phase HPLC (EP method). We strictly quantify free N-Acetyl-L-Cysteine (98.5%–101.5%), verify specific optical rotation ([α]D = +21.0° to +27.0°), and limit free unacetylated L-cysteine (≤ 0.50%) and L-cystine dimer (≤ 0.50%), preventing active degradation or premature disulfurization.
• Moisture-Resistant & Nitrogen-Flushed Packaging: In the presence of ambient moisture and oxygen, pure NAC powder can undergo slow oxidation, liberating trace volatile sulfur compounds. We package our material in heavy-duty food/pharma-grade double-polyethylene liners within vacuum-sealed, nitrogen-flushed aluminum barrier bags (1 kg, 5 kg) and robust 25 kg fiber export drums, guaranteeing low-odor stability across its 24-month shelf life.
• Comprehensive ICP-MS & Heavy Metal Screening: Batch-tested via high-resolution ICP-MS to ensure heavy metals (Lead, Arsenic, Cadmium, Mercury) strictly comply with California Prop 65 and USP limits. Sealed in food/pharma-grade export packaging to maintain stability during international sea and air freight.

7. FAQ

Q1: What is the biological difference between taking N-Acetyl-L-Cysteine (NAC) and taking direct L-Glutathione?
A1: While both aim to elevate cellular glutathione levels, their pharmacokinetics and cellular absorption pathways differ fundamentally:

• Direct Oral L-Glutathione: Glutathione is a tripeptide. When ingested, it is largely cleaved in the small intestine by the brush-border enzyme gamma-glutamyltransferase (γ-GT) into its individual amino acids before absorption, resulting in variable cellular bioavailability unless formulated in specialized liposomal or sublingual matrices.
• N-Acetyl-L-Cysteine (NAC): Acts as an optimized intracellular glutathione precursor. Its acetylated nitrogen protects the molecule from rapid degradation in the digestive tract, allowing it to easily enter enterocytes and pass through cellular membranes via amino acid transporters. Once inside cells, it is deacetylated to provide L-cysteine—the sole rate-limiting building block—allowing the cell to synthesize fresh, endogenous reduced glutathione according to its exact physiological demands.

Q2: Why is the combination of NAC and Glycine (“GlyNAC”) gaining massive attention in longevity geroscience?
A2: Glutathione synthesis requires three amino acids: cysteine, glycine, and glutamate. While glutamate is abundant in normal metabolic cycles, research from Baylor College of Medicine demonstrated that aging cells are severely deficient in both cysteine and glycine. Supplementing NAC alone provides cysteine, but often leaves glycine as the secondary rate-limiting constraint. Combining equimolar ratios of NAC and Glycine (GlyNAC) simultaneously satisfies both nutritional requirements, leading to clinically documented restorations of youthful glutathione levels, enhanced mitochondrial fat oxidation, reduced oxidative stress markers, and improved physical and cognitive vitality in older adults.

Q3: How does N-Acetyl-L-Cysteine function as a mucolytic agent in respiratory conditions?
A3: In chronic bronchitis, COPD, and viral lung infections, mucus becomes thick and stagnant due to extensive disulfide (-S-S-) cross-linking between mucin glycoprotein polymers. The free sulfhydryl (-SH) group of NAC directly targets these cross-links. Through a chemical thiol-disulfide exchange reaction, NAC donates its hydrogen atom, breaking the large disulfide bonds into smaller, disconnected sulfhydryl units. This reduces sputum viscosity and elasticity, allowing the mucociliary escalator to clear congested airways and improving alveolar gas exchange.

Q4: What is the clinically supported daily dosage of N-Acetyl-L-Cysteine in finished formulations?
A4: Clinical dosages vary by formulation format and target functional claim:

• General Antioxidant & Daily Immune Maintenance: 600 mg per day (the standard single-capsule dose).
• Intensive Broncho-Pulmonary & Mucolytic Support: 600 mg taken two to three times daily (1,200 mg – 1,800 mg total daily).
• Clinical GlyNAC Longevity Protocol: 1,200 mg to 2,400 mg of NAC paired with an equimolar amount of Glycine (divided into two daily servings).
• Liver Detoxification & Hangover Defense Formulations: 500 mg to 1,000 mg taken before or immediately after alcohol exposure.
• Functional Mushroom Coffee & Beverage Sticks: 200 mg to 400 mg per serving (using our low-odor grade).

Q5: What is the MOQ for bulk N-Acetyl-L-Cysteine orders?
A5: We support agile product commercialization with flexible minimum order quantities starting from just 1 kg for ultra-pure USP/EP crystalline powders and DC-95 direct compression granules, scaling smoothly up to recurring multi-ton commercial container contracts.

8. References

1. PubChem: Acetylcysteine Compound Summary (CID 12035) – National Center for Biotechnology Information.
2. PubMed Central: Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Aging Adults Improves Glutathione Deficiency, Mitochondrial Impairment, Oxidative Stress, and Physical Function: Results of Clinical Trials – National Institutes of Health research database.

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