N-Acetyl Cysteine (NAC) is a powerful amino acid derivative that plays a crucial role in glutathione production, detoxification, and immune support. It is widely used for liver health, respiratory function, and reducing oxidative stress.
With many NAC supplements available, it’s essential to choose one that meets quality, potency, and purity standards. We have researched and reviewed the six best NAC supplements to help you find the right one for your needs.
The 6 Best NAC Supplements (N-Acetyl Cysteine) in 2025
1. Fresh Nutrition NAC 600mg (Best for Purity & Third-Party Testing)
Price: $19.97
Fresh Nutrition NAC 600mg is a high-potency N-acetylcysteine supplement designed to support liver function, lung health, and immune defense. With 600mg per capsule, it provides an optimal daily dose of NAC sourced from a pure and tested ingredient. Manufactured in an FDA-registered and GMP-certified facility, this supplement ensures third-party testing for quality, potency, and purity.
Benefits:
- Liver Support: Enhances detoxification and promotes liver function.
- Lung Health: Helps clear mucus buildup and supports respiratory function.
- Immune System Boost: Precursor to glutathione, a critical antioxidant for immune defense.
- Antioxidant Protection: Fights oxidative stress and reduces free radicals.
What it Contains:
- 600mg of N-Acetylcysteine (NAC) per capsule
- No fillers or additives
- Vegetarian capsules
Pros:
✔ High potency with 600mg NAC per serving
✔ Third-party tested for purity and potency
✔ Vegan, non-GMO, gluten-free, and soy-free
✔ Manufactured in an FDA-registered, GMP-certified facility
✔ 90 capsules per bottle (3-month supply)
Cons:
✖ Some users report a strong sulfuric smell, which is typical of NAC
✖ Capsules may be large for some users to swallow
Customer Feedback:
- Quality & Value: Customers praise the high-quality formulation and reasonable price for the quality.
- Ease of Swallowing: Most users find the capsules easy to swallow, but a few mention they are on the larger side.
- Effectiveness: Many reviews highlight improved detoxification, lung health, and energy levels after use.
- Taste & Smell: Some users report no aftertaste, while others mention a mild sulfur-like smell.
Summary: Fresh Nutrition NAC 600mg is a high-quality supplement designed for liver, lung, and immune support. With a potent dose, third-party testing, and a clean formula, it’s an excellent choice for those seeking a pure and effective NAC supplement.
2. Double Wood NAC 1000mg (Best High-Potency NAC Supplement)
Price: $19.95
Double Wood NAC 1000mg is a high-strength N-acetylcysteine supplement designed to boost glutathione levels, support liver function, and provide antioxidant protection. With 1000mg per serving (500mg per capsule, taken twice daily), this supplement offers a potent dose for optimal detoxification and immune defense. Manufactured in the USA in a GMP-certified facility, it is third-party tested for purity and safety.
Benefits:
- Liver Support: Aids in detoxification and protects against oxidative stress.
- Glutathione Boost: Enhances the body’s production of this essential antioxidant.
- Antioxidant Protection: Helps fight free radicals and reduces inflammation.
- Immune System Strengthening: Supports immune function by reducing oxidative stress.
What it Contains:
- 1000mg of N-Acetylcysteine (NAC) per serving (2 capsules per dose)
- Vegetarian formula
- No artificial fillers or preservatives
Pros:
✔ High-potency formula (1000mg per serving)
✔ Manufactured in a GMP-certified facility
✔ Third-party tested for purity and potency
✔ Vegetarian, non-GMO, and gluten-free
✔ 105 servings per bottle (over 3 months’ supply)
Cons:
✖ Requires taking 2 capsules per serving for a full dose
✖ Some users report a mild sulfur smell, which is typical for NAC
Customer Feedback:
- Quality & Effectiveness: Users report noticeable improvements in liver health, energy levels, and detoxification.
- Ease of Use: While capsules are easy to swallow, some users don’t like taking two per serving.
- Potency & Value: Customers appreciate the high-strength formula and long-lasting supply.
- Taste & Smell: Some mention a slight sulfuric odor, but it is expected with NAC supplements.
Summary: Double Wood NAC 1000mg offers a high-potency dose for those seeking strong liver support and antioxidant benefits. With third-party testing, a vegetarian formula, and a generous 3-month supply, it’s a great choice for individuals looking for an effective NAC supplement.
3. Deal Supplement NAC + Glutathione (Best for Enhanced Antioxidant Support)
Price: $29.99
Deal Supplement NAC + Glutathione offers a dual-action antioxidant formula, combining 1,000mg of NAC with 50mg of reduced glutathione per serving. This high-potency blend supports liver detox, lung function, and immune health while promoting the body’s natural glutathione production. It’s third-party lab tested, non-GMO, and free from common allergens like gluten, soy, and dairy.
Benefits:
- Liver Detoxification: Supports healthy liver function by increasing glutathione levels.
- Lung & Respiratory Health: Helps reduce mucus buildup and supports breathing.
- Powerful Antioxidant Boost: Combines NAC with reduced glutathione for enhanced cellular protection.
- Cognitive & Mental Support: May aid brain health and cognitive function.
What it Contains:
- 1,000mg N-Acetyl L-Cysteine (NAC) per serving
- 50mg of Reduced Glutathione per serving
- No artificial fillers or preservatives
Pros:
✔ Dual-action formula with NAC + glutathione
✔ High antioxidant potency for liver and immune support
✔ Third-party lab tested for purity and potency
✔ Non-GMO and free from gluten, dairy, soy, wheat, and nuts
✔ Long-lasting 240-capsule supply (80 servings per bottle)
Cons:
✖ Requires 3 capsules per serving, which may be inconvenient for some users
✖ Some customers report a strong sulfuric smell, typical of NAC supplements
Customer Feedback:
- Anti-Inflammatory Benefits: Many users report improved immune function, reduced inflammation, and better liver support.
- Quality & Potency: Customers praise the high-quality formulation and the combination of NAC with glutathione.
- Effectiveness: Users notice improvements in mood, respiratory health, and detox support.
- Taste & Smell: Some reviews mention a strong sulfuric odor, which is common with NAC.
Summary: Deal Supplement NAC + Glutathione offers a unique dual-action antioxidant blend, combining the benefits of NAC and glutathione in one formula. With high potency, third-party testing, and a long-lasting supply, it’s an excellent choice for those looking to boost detoxification and immune health.
4. NatureBell NAC + Quercetin (Best for Immune and Cellular Health Support)
Price: $19.99
NatureBell NAC + Quercetin is a double-strength antioxidant formula, featuring 1,200mg of NAC and 100mg of quercetin dihydrate per serving. This synergistic combination supports liver detox, lung function, immune defense, and cellular protection. Manufactured with non-GMO ingredients, third-party lab-tested, and free from soy, gluten, and artificial preservatives, this supplement ensures high purity and potency.
Benefits:
- Liver & Lung Support: NAC helps detoxify the liver and supports respiratory function.
- Immune System Strengthening: Quercetin provides additional anti-inflammatory and immune-boosting benefits.
- Cellular Protection: Acts as an intracellular antioxidant, protecting cells from oxidative stress.
- Cognitive & Heart Health: Quercetin may support brain function and cardiovascular health.
What it Contains:
- 1,200mg N-Acetyl L-Cysteine (NAC) per serving
- 100mg Quercetin Dihydrate per serving
- No artificial fillers or preservatives
Pros:
✔ High-potency NAC (1,200mg) with added quercetin for enhanced benefits
✔ Double antioxidant protection for immune and cellular health
✔ Non-GMO, soy-free, gluten-free, and preservative-free
✔ Third-party lab-tested for safety and purity
✔ 240 capsules per bottle (80 servings per supply)
Cons:
✖ Requires 3 capsules per serving, which may be inconvenient for some users
✖ Some customers report mild stomach discomfort, possibly due to quercetin
Customer Feedback:
- Effectiveness & Quality: Users report improved immune function, cellular protection, and detox support.
- Immune & Respiratory Benefits: Many customers note better lung health and reduced inflammation.
- Cognitive Function: Some users find it beneficial for mental clarity and focus.
- Taste & Smell: Mixed reviews—some say it has no smell, while others report a mild sulfuric odor.
Summary: NatureBell NAC + Quercetin offers a potent combination of NAC and quercetin for immune, lung, and cellular support. With high purity, third-party testing, and a long-lasting supply, it’s an excellent choice for those looking to enhance antioxidant protection and overall health.
5. NOW Foods NAC 600 mg with Selenium
Price: $11.28
NOW Foods NAC 600 mg is a trusted NAC supplement that includes selenium and molybdenum for enhanced antioxidant and detoxification support. It is designed to protect against oxidative stress, support cellular health, and boost immune function. The product is Non-GMO, vegan, gluten-free, and UL Certified, ensuring a high-quality formulation.
Benefits
- Antioxidant Protection – Helps combat free radicals and oxidative stress.
- Supports Cellular Health – Aids detoxification and liver function.
- Immune System Support – Works alongside selenium to strengthen immunity.
- Respiratory Health – Promotes lung function and reduces mucus buildup.
What it Contains
- N-Acetyl Cysteine (NAC) – 600 mg
- Selenium (from L-Selenomethionine) – 25 mcg (45% DV)
- Molybdenum – Included for additional enzyme support
Pros
✔ Includes Selenium for enhanced glutathione production
✔ Non-GMO, vegan, and gluten-free
✔ GMP Certified for quality assurance
✔ Well-known and reputable brand
Cons
✖ Some customers report black spots appearing in the capsules due to oxidation
✖ Slightly lower NAC dose compared to other products
Customer Feedback
- Quality & Effectiveness: Many users trust NOW Foods for high-quality and effective supplements. Customers report benefits for liver support, immune health, and detoxification.
- Health Benefits: Positive reviews mention improved respiratory function, reduced inflammation, and better general well-being.
- Side Effects: A few customers noted oxidation issues where black spots appeared on the capsules, but NOW Foods clarified this as a natural reaction, not contamination.
Summary: “NOW Foods NAC 600 mg is a well-rounded supplement with added selenium for extra antioxidant support. While some users noted oxidation issues, the brand remains highly trusted for quality and effectiveness.”
6. Nutricost NAC 600 mg
Price: $15.95
Nutricost delivers a clean and simple NAC supplement, providing 600 mg per capsule. It comes in a 180-capsule bottle, offering a long-lasting supply. The product is vegan, non-GMO, and free of gluten.
Benefits
- Supports antioxidant protection and immune health
- Aids in liver detoxification
- Helps reduce inflammation and stress
- May support brain and respiratory function
What it Contains
- N-Acetyl L-Cysteine (NAC): 600 mg
- Other Ingredients: Hypromellose (capsule), rice flour, magnesium stearate, stearic acid
Pros:
✔ Simple, high-purity formula with no additives
✔ Vegan-friendly and non-GMO
✔ Manufactured in an NSF-certified, GMP-compliant facility
✔ Third-party tested for quality
Cons:
✖ Lower dosage per capsule compared to some brands
✖ Some customers report an unpleasant smell
Customer Feedback
Customers appreciate the effectiveness of this NAC supplement, particularly for reducing inflammation and stress. It is considered a good value for money, with many users reporting positive results in immune health, detox, and overall well-being. However, a few customers mentioned that the capsules have an unpleasant smell.
Summary: Nutricost NAC 600 mg offers a clean, vegan-friendly supplement with a simple formula. While it has a lower dose per capsule, it provides excellent quality and is well-rated for immune and detox support.
Final Note
NAC is a powerful antioxidant that supports liver health, lung function, and immunity. Whether you’re looking for a high-potency dose, added antioxidants, or a budget-friendly option, these top NAC supplements provide the best choices.