What Is NAC?

N-acetyl-L-cysteine (NAC) is the acetylated form of the amino acid L-cysteine and the most effective oral way to raise glutathione, the body’s central intracellular antioxidant. As a glutathione precursor it Supports the glutathione antioxidant system, and as a mucolytic it breaks the disulfide bonds in mucus, which is why it has decades of pharmaceutical use in respiratory care. The acetyl group stabilizes the molecule and improves absorption versus plain cysteine. Core Nutrix supplies USP-grade material assayed at 98.5-101%.

Key Facts at a Glance

• Active content: NAC 98.5-101% (USP assay)
• CAS number: 616-91-1
• Appearance: White crystalline powder
• Typical serving: 600 mg per day
• Odor: Characteristic mild sulfur note
• Grade: USP monograph
• Packaging: 25 kg drum (custom formats available)
• Shelf life: 24 months in sealed, cool, dry storage

Origin & Sourcing

Produced from fermentation-derived L-cysteine followed by acetylation and purification to USP monograph, with cystine and related impurities tightly controlled. The powder and granular grades both assay at 98.5-101%, and each batch is released with COA covering assay, impurities, heavy metals and microbiology. Vegan documentation is available since the cysteine backbone is fermentation-derived rather than animal-sourced.

Key Benefits

• Raises glutathione, the body’s central intracellular antioxidant
• Supports glutathione pathways
• Mucolytic (thiol) chemistry used in technical applications
• Antioxidant defense against oxidative stress
• Studied for metabolic and mental-health support
• USP monograph grade with tight assay range

Applications

Antioxidant capsules, respiratory-support formulas, liver-support stacks, hangover products, immune gummies and beauty-from-within lines. NAC is also a standard companion to milk thistle in liver formulas and to glycine in glutathione-boosting stacks. Beyond capsules, NAC’s granular grade suits effervescent tablets and coated tabs, and it appears in immune and antioxidant gummies. Glutathione-boosting stacks typically pair it with glycine, while liver formulas add milk thistle and B-vitamins.

Why 2026 Matters

Glutathione has become one of the most searched supplement terms, and NAC is its most reliable oral precursor – a stable, well-dosed ingredient with a pharmaceutical heritage. Respiratory wellness demand and the liver-support and longevity trend both feed the category, and NAC’s expansion from pharmacy ingredient to mainstream supplement keeps volumes growing. USP-grade supply with controlled odor is the practical differentiator brands need. NAC sits at the intersection of three durable trends: antioxidant and longevity interest, respiratory wellness, and liver-support products. It is also one of the few supplement ingredients with genuine pharmaceutical heritage, which gives it credibility with health professionals. The practical barrier for brands has always been odor and stability, so a USP-grade supplier with odor-controlled production is the key commercial differentiator – and the reason most NAC brands stay with pharma-grade sources.

Science Snapshot

NAC is deacetylated to cysteine, the rate-limiting substrate for glutathione synthesis, and clinical studies confirm it raises blood glutathione. Its mucolytic action – cleaving disulfide bonds in mucoproteins – is a classic pharmaceutical indication, and research has extended to metabolic markers, mental health as an adjunct, and antioxidant protection against environmental pollutants. Typical supplement doses run 600 mg once or twice daily. Glutathione cannot be taken up intact by most cells, which is why the precursor strategy dominates: NAC crosses into cells, is deacetylated to cysteine, and cysteine combines with glutamate and glycine through two enzyme steps to form glutathione. Co-supplementing glycine maximizes synthesis, and vitamin C keeps glutathione in its reduced, active form. Beyond glutathione, NAC’s direct antioxidant and mucolytic actions are independent mechanisms, which explains its breadth of use from respiratory care to liver-support formulas. Clinical work also shows NAC raising glutathione in tissues where oxidative stress is highest, such as the liver and lungs.

Quality & Specifications

• Actives: NAC 98.5-101% (USP assay)
• Appearance: White crystalline powder
• Grades: Powder, granular
• Packaging: 25 kg drums (custom formats available)
• Shelf life: 24 months in sealed, cool, dry storage
• Testing: USP assay, cystine, heavy metals, microbiology, ethylene oxide (EtO), aflatoxins, PAH, pyrrolizidine alkaloids (PAs)
• Compliance: Pesticide residue screened to EU MRLs (EC) 396/2005; Proposition 65 (Prop 65) statement and full contaminant documentation on request
• Note: Business-to-business ingredient information only. Not intended to diagnose, treat, cure or prevent any disease.

Safety & Regulatory

Well tolerated at 600-1200 mg per day; occasional GI upset is reported at higher doses. Use under medical supervision in asthma and during pregnancy, and stop before elective surgery.

Formulation Notes

The main practical challenge is NAC’s sulfur odor, managed through encapsulation, flavor systems and moisture control; the granular grade improves flow in tableting. Effervescents and coated capsules are common formats. Pairs with glycine for glutathione synthesis, with milk thistle in liver stacks, and with vitamin C to keep glutathione in its reduced form.

How It Compares

• NAC vs glutathione: oral glutathione is poorly absorbed and debated; NAC is the precursor route with clinical evidence for raising glutathione levels.
• NAC vs L-cysteine: the acetyl group stabilizes cysteine against oxidation and improves uptake – NAC is the standard supplement form.
• USP vs food grade: USP monograph means pharmacopoeia assay, impurity and identification standards suitable for both supplements and pharma.
• Powder vs granular: powder suits capsules and blends; granules flow better in high-speed tableting and effervescent lines.

Frequently Asked Questions (FAQ)

What assay does this NAC meet?

98.5-101.0% by USP assay, supplied as powder or granules.

Can you provide a COA and third-party test report?

Yes. Every batch ships with a Certificate of Analysis, and third-party testing is available on request.

What is the MOQ and packaging?

Standard packaging is a 25kg drum. Please contact us for current MOQ and sample availability.

How do you manage the sulfur odor?

Through moisture control in production and packaging; we also advise on encapsulation and flavor systems for finished products.

What serving is typical?

600 mg once or twice daily is the common supplement range.

Is it suitable for effervescents?

Yes. The granular grade works in effervescent and coated tablet formats.

Is a vegan grade available?

Yes. The cysteine backbone is fermentation-derived, and vegan documentation is available.

How to Get Started

1. Tell us your format and target dose – capsules, powders, tablets, gummies or beverages.
2. We confirm the matching grade, send the specification sheet and a free sample.
3. Approve the sample and run a trial batch; we lock the COA and lead time.
4. Scale to full production with batch-to-batch consistency guaranteed.