THE PROMISE
High-potency NAC. 600 mg per capsule. Professional grade, broad-spectrum.
N-Acetyl Cysteine is one of the most clinically researched amino acid derivatives available — a direct precursor to glutathione, the body's most potent antioxidant. Our high-potency, free-form NAC delivers 600 mg per capsule in a clean vegetarian HPMC capsule with no unnecessary excipients. Practitioner-formulated since 1999.
Glutathione Precursor
NAC is the rate-limiting precursor to glutathione — the body's master antioxidant. Without adequate cysteine, glutathione synthesis stalls.*
Liver Defense
Recognized for its role in glutathione production, NAC supports the liver's natural detoxification pathways and helps neutralize reactive oxygen species.*
Respiratory Support
NAC supports healthy mucus viscosity in the airways — promoting easier breathing and respiratory resilience during seasonal immune challenges.*
Neuroprotection
Emerging research supports NAC's role in glutamate regulation and neurological health — supporting mental clarity, cognitive wellness, and balanced antioxidant activity.*
WHY IT WORKS
Broad Spectrum Protection
Master Antioxidant Support
NAC raises glutathione — the body's most powerful antioxidant — protecting cells from oxidative damage, slowing cellular aging, and supporting immune resilience at its root.*
Liver & Detoxification
Supports Phase II liver detoxification pathways. NAC replenishes the glutathione reserves the liver uses to neutralize metabolic byproducts and reactive compounds.*
Respiratory & Lung Health
Acts as a mucolytic — supporting healthy mucus viscosity in the airways and promoting normal respiratory function.*
Brain & Mood Resilience
Supports glutamate balance, the brain's primary excitatory neurotransmitter, promoting mental clarity and cognitive wellness.*
Customer Reviews
Tried, tested,
truly loved.
YOUR PROTOCOL
When to take it,
and why it matters
NAC works cumulatively and is best taken with food to minimize GI sensitivity. For maximum benefit, split dosing across morning and evening to maintain consistent glutathione synthesis throughout the day and overnight.*
MORNING
Take 1–2 capsules with breakfast. Morning dosing activates NAC’s antioxidant cascade during your most metabolically active hours, supporting liver detoxification and glutathione production throughout the day.*
WHY IT WORKS
Glutathione synthesis ramps up with morning metabolic activity — this is when your body uses antioxidant reserves most.*
WITH MEALS
For maximum effect, split your dose across two meals. Taking NAC with food reduces any GI sensitivity while maintaining steady plasma cysteine levels throughout the day.*
WHY IT WORKS
Consistent plasma cysteine levels sustain glutathione synthesis continuously — the key to cumulative cellular protection.*
EVENING
An evening dose supports the liver’s overnight detoxification cycle. The body performs peak Phase II detox during sleep — NAC provides the cysteine substrate this process requires.*
WHY IT WORKS
The liver performs its deepest detoxification work at night. NAC before bed ensures the glutathione reserves are fully stocked.*
SUGGESTED USE
Simple capsules. Clinical dosing.
Vegetarian HPMC capsules. Take with food. As directed by your healthcare professional, 1–3 capsules daily.
Full-Spectrum Formula
What's inside,
and why it matters.
Glutathione, from the inside out.*
NAC is the acetylated form of L-cysteine, an amino acid that serves as the rate-limiting precursor for glutathione biosynthesis. Unlike glutathione supplements which cannot survive digestion, NAC crosses cell membranes and is converted directly to cysteine — the substrate the body needs to produce its own glutathione.
Free-form N-Acetyl Cysteine · Pharmaceutical grade · Vegetarian HPMC capsule.
Free-form N-Acetyl Cysteine · 600 mg per capsule · 120 servings. View Supplement Facts →
Dr. Devin Ryerson
Founder & Chief Curator · Est. 1999Why It Matters
Built by someone with
personal stakes in it.
Devin started Pure Prescriptions in 1999 after battling Hodgkin's Lymphoma and losing his father to leukemia. That experience made him the most stubborn kind of formulator — one who refuses to ship anything he wouldn't take himself.
Every ingredient here earned its place through clinical evidence, third-party testing, and that same personal lens — the five collagen types, the organic fruiting-body mushrooms, the co-factors. Nothing is decorative.
"Pure Prescriptions has always been more personal than corporate. Built by family. Still independent."
Our StoryYour Journey
What to expect
NAC works cumulatively. Here's what customers experience over time.
WEEK 1–2
Antioxidant Activation
NAC immediately begins replenishing cysteine stores and supporting glutathione synthesis. Many users report improved vitality and a sense of cellular wellbeing within the first two weeks.*
GLUTATHIONE SYNTHESIS BEGINS
WEEK 4
Liver & Detox Support
With consistent dosing, the liver's Phase II detoxification capacity improves measurably. Users with demanding lifestyles often report clearer thinking and sustained afternoon energy.*
PHASE II LIVER DETOX
WEEK 8
Respiratory & Mood
Respiratory function support becomes more pronounced — particularly during seasonal respiratory demand. Glutamate balance supports mental wellbeing and a sense of calm focus.*
RESPIRATORY + COGNITIVE SUPPORT
WEEK 12
Full Protocol Benefit
At 12 weeks, glutathione reserves are robustly replenished and the full breadth of NAC's antioxidant, detoxification, and neurological support benefits are well-established.*
COMPLETE ANTIOXIDANT DEFENSE
RESULTS ARE BEST WITH DAILY USE · MOST CUSTOMERS SEE FULL BENEFITS BY WEEK 12
Results vary from person to person.
The Science of NAC
The body can’t make
glutathione without it.
NAC is the missing link.
Glutathione is your body’s most powerful antioxidant — but it can’t be absorbed orally. NAC bypasses this barrier by delivering the cysteine your cells need to synthesize their own glutathione, directly at the cellular level.
- Free-form N-Acetyl Cysteine — 600mg per capsule, pure and unbound
- Precursor to glutathione — the master cellular antioxidant
- Supports liver Phase II detoxification and toxic load clearance
- Vegetarian hypromellose capsule — label also lists ascorbyl palmitate
Antioxidant Defense
Have Questions?
Everything you need to know.
Honest answers — no marketing spin. If your question isn’t here, our team responds within one business day.
N-Acetyl Cysteine (NAC) is an amino acid derivative that serves as the direct precursor to glutathione — your body’s master antioxidant. Unlike glutathione itself, NAC survives digestion, crosses cell membranes, and is converted to cysteine, which your cells use to produce glutathione on demand. It’s one of the most broadly researched supplements in clinical use.
Glutathione is made from three amino acids: glycine, glutamate, and cysteine. Cysteine is the rate-limiting step — meaning glutathione synthesis is determined by how much cysteine is available. NAC delivers a stable, bioavailable form of cysteine that the body converts rapidly into glutathione in the liver and other tissues.
Yes. NAC has an extensive safety record going back decades of clinical use. At standard doses (600–1800mg daily), NAC is well-tolerated by the vast majority of users. Taking with food reduces the rare GI sensitivity some people notice.
Yes. NAC pairs well with Vitamin C (which regenerates glutathione), Alpha Lipoic Acid, and Milk Thistle for liver support. There are no known dangerous interactions with common supplements. If you are on prescription medications, consult your practitioner — NAC can potentiate the effects of certain drugs.
Many users report improved energy and sense of wellbeing within the first 1–2 weeks. Respiratory and liver support may develop over 4–8 weeks of consistent daily use. Glutathione reserve rebuilding, particularly for those with depleted levels, can take 8–12 weeks of consistent dosing.
NAC can be taken at any time with food. For detoxification support, an evening dose leverages the liver’s peak overnight detox cycle. For respiratory support and general antioxidant defense, a morning dose with breakfast is ideal. Splitting doses between morning and evening provides the most consistent plasma levels.
Doctor’s Protocol
How I’d build your antioxidant foundation.
“NAC builds the glutathione reserves. CoQ10 protects mitochondrial integrity. Magnesium ensures the enzymatic conversion works. Probiotics keep the gut axis clear so the liver can do its job. Each layer reinforces the next.”
In Order of Priority
4 Products · 1 Protocol
Doctor's First Choice
N-Acetyl Cysteine (NAC)
Start here. Free-form NAC at 600mg per capsule — the direct glutathione precursor your cells need for antioxidant defense, liver detoxification, and cellular protection.
Cellular Energy · Antioxidant
Bioactive Coenzyme Q10
CoQ10 and glutathione are synergistic antioxidants — each regenerates the other in the mitochondrial electron transport chain, amplifying your total antioxidant capacity.
Deep Recovery · Sleep
Magnesium Glycinate
Magnesium is required for glutathione synthesis as an enzymatic cofactor. Adequate magnesium status ensures NAC's cysteine donation converts efficiently to active glutathione.
Gut Health · Immune
Digestive Defense™
A healthy gut microbiome enhances the bioavailability of NAC and supports the liver-gut axis — the primary detoxification pathway NAC is designed to reinforce.
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