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Understand what you're taking

Dr. Stewart's notes on how this formula works and who it's for.

How It Works

Glutathione is made from three amino acids: cysteine, glutamate and glycine. Cysteine is usually the one in shortest supply.*

Genes like CTH affect how much cysteine your body makes on its own.*

NAC is a stable form of cysteine. Your body converts it and uses it to build glutathione.*

Is This Right for You?

A good fit if you

  • Your NineTwo Detox report flags cysteine production or recommends NAC Pro
  • You want simple, single-ingredient glutathione support
  • One capsule a day with food fits your routine

Talk to your provider first if you

  • Are pregnant or nursing
  • Want to give it to a child

Good to know

A sulfur smell is normal for NAC.

Take it with food to avoid an upset stomach.

How to Take It

Take 1 capsule, 1 to 2 times daily with food, or as directed by your healthcare professional. Children: as directed by a healthcare professional.

NAC PRO

NAC PRO

Doctor's Formulation Rationale

Glutathione is your body's main antioxidant and one of its most important detox tools, and your cells make it themselves. What usually limits how much they can make is cysteine. Some genetic mutations slow down how the body produces cysteine, which caps glutathione no matter how well you eat. NAC is a stable form of cysteine your body can use right away, so it removes that bottleneck directly. I keep this one simple on purpose: one ingredient, at a dose that's easy to adjust.

— Kendal Stewart, MD
$40.94 USD
$40.94 USD
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Why people take it

  • Supports healthy glutathione production*
  • Supports the body's natural detoxification*
  • Provides antioxidant support*
  • Helps protect cells from everyday oxidative stress*
  • Supports healthy respiratory function*

Supplement Facts & Ingredients

Serving Size: Serving Size 1 Capsule, Servings Per Container 90
Active Ingredient Amount Per Serving % Daily Value
N-Acetyl-L-Cysteine (NAC) 500 mg *
*Daily Value not established.
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GENETIC PANEL MATCH · DETOXIFICATION ANALYSIS

Your genes may already be pointing you here

NAC Pro is one of the formulas our Detoxification Analysis can recommend. The report looks at the genes that shape how much cysteine your body makes, then shows where your glutathione production may need support.

View DNA Test Panel ($169)

CTH

Making cysteine

NAC supplies cysteine directly.

AHCY / CBS

Earlier steps on the path to cysteine

NAC skips those steps by supplying cysteine.

Your genes don't diagnose anything. They show tendencies, and your report turns them into a plan.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Board–Certified MD Founded
Board–Certified MD Founded
30+ years treating complex chronic patients
CLIA–Certified US Lab
CLIA–Certified US Lab
High-depth genetic sequencing precision
Active Methylated Co–Factors
Active Methylated Co–Factors
Bioavailable nutrients that bypass SNP blocks
100% Third–Party Batch Tested
100% Third–Party Batch Tested
Verified purity, zero fillers, cGMP certified

Frequently Asked Questions

Personalized wellness through genetic testing, education, and targeted supplementation.
Our advanced panel tests key enzymes including MTHFR and COMT to uncover pathway bottlenecks and optimize energy production.
Evaluates hepatic phase I and phase II clearance genes to optimize endogenous glutathione pathways and cellular detox.
A non-invasive cheek swab collected at home is analyzed at our CLIA-certified laboratory with results available in 2–3 weeks.
Comprehensive clinical panels engineered specifically to guide targeted nutrition, co-factor dosing, and bio-individual lifestyle protocols.
Yes, our bioavailable co-factor formulas are crafted specifically to bypass the exact SNP blocks identified in your panel.