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Seeking Health we will be closed on May 27th in observance of the holiday. We will resume normal business hours on May 28th.
Seeking Health we will be closed on May 27th in observance of the holiday. We will resume normal business hours on May 28th.

NAC (N-Acetyl-L-Cysteine)

  • Active ‘L’ form of N-Acetyl-Cysteine (NAC) in a Free Form
  • Key component of glutathione formation
  • Supports healthy liver, lungs, immune system & detoxification
For a limited time, Buy 1 Get 1, Buy 3 Get 3 or Buy 6 Get 6. Select and add to cart.

Who Needs NAC Vitamins

Your cells are constantly under attack. Free radicals and oxidative stress from environmental toxins can significantly burden your liver. Even normal processes like hormone metabolism contribute to toxicity. In our modern world, maintaining healthy antioxidant status and detoxification pathways is essential for your health.

NAC by Seeking Health provides 500 mg of N-acetyl-L-cysteine per vegan capsule.

NAC (N-acetylcysteine) is an important sulfur-containing amino acid. By facilitating glutathione production, NAC supports healthy detoxification and antioxidant function in virtually every cell of the human body. NAC also has the unique ability to support the normal break up of mucus in the lungs, making it popular for lung and immune health protocols.

NAC acts directly and indirectly as an antioxidant. Its unique chemical structure contains an outer sulfur group. This allows NAC to act as an antioxidant, particularly for NO2 and hydroxyl radicals.

NAC is also a bioavailable source of cysteine. This rate-limiting amino acid is needed to build glutathione, which acts as your body’s master antioxidant.

Your liver requires glutathione for multiple functions. Glutathione can readily donate electrons to act as a potent antioxidant. It also binds toxins, drugs, and hormones so your body can excrete them. The World Health Organization (WHO) recognizes NAC as a substance that supports liver cell health, especially with exposure to compounds known to cause liver damage.

It is well known that cells (particularly immune, lung, reproductive, and brain cells) function optimally when glutathione levels are in peak range. However, glutathione levels decline naturally with age. They are depleted even faster when the body does not have enough cysteine.

NAC by Seeking Health supports healthy glutathione levels by providing a bioavailable source of cysteine.

Use of NAC can also support lung and respiratory health. It has been well established that NAC supports the normal thinning of lung mucus. It does this by interfering with the disulfide protein bonds found in mucus. This allows mucus to be more easily expelled from the lungs.

NAC supports healthy:

  • Lung tissue
  • Respiratory function
  • Glutathione production
  • Antioxidant status
  • Immune health
  • Hormone balance
  • Liver health
  • Detoxification
  • Oxidative damage defenses
  • Brain & Nerve health
  • Reproduction & Fertility
  • Healthy aging processes

In most supplement forms found on the market, glutathione may not be as well-absorbed or utilized as NAC. Supplementing with high-quality liposomal glutathione may not be an option for everyone due to the increased cost and strong sulfur taste. NAC is a cost-efficient way to support natural glutathione and antioxidant activity in your body.

NAC by Seeking Health supports healthy glutathione production, detoxification, respiratory health, and much more. Always keep a bottle in your immune toolbox–this popular product tends to fly off the shelves!

Customer Review

Life Changing

My functional nutritionist recommended this supplement for me, as he takes it himself. I noticed almost an immediate difference in my mood and energy levels. I consistently hear the benefits of NAC across health professionals with new substantial evidence arising. ~Emmy R.

Key Ingredients In NAC Vitamins

  • NAC (N-Acetyl-L-Cysteine): A sulfur-containing amino acid compound that is a precursor to glutathione, giving it powerful antioxidant and detoxification properties. NAC also has the unique ability to support the normal breakup of mucus in the lungs.

Why NAC Vitamins Works

N-acetyl-cysteine (NAC) is derived from the amino acid L-cysteine. NAC by Seeking Health is a well-absorbed supplemental form of cysteine. This important amino acid is a building block of glutathione, known as your body’s “master antioxidant.” The health benefits of NAC are largely related to its role in glutathione production.

NAC is known to assist in three main areas of health: antioxidant activity, detoxification, and lung health.

Antioxidant Activity

NAC acts as a powerful antioxidant in your body. It does this directly and indirectly. First, NAC itself provides antioxidant support for free radical protection.

The word antioxidant is defined by a compound having the capacity to donate an electron readily. The sulfur protruding from cysteine allows electrons to attach and detach easily. In particular, NAC is known to interact with hypochlorous acid and hydroxyl radicals by donating an electron to neutralize them.

The second way NAC has powerful antioxidant properties is via its role in glutathione production. NAC provides the amino acid cysteine. Your cells make glutathione from three amino acids: cysteine, glutamic acid, and glycine. Of these, cysteine is the rate-limiting ingredient needed to synthesize glutathione. Without enough cysteine, glutathione production will decline.

Detoxification properties

NAC also supports normal detoxification pathways via various mechanisms. NAC is a precursor to sulfate, the most commonly used detoxification compound in the body. Whether you are metabolizing hormones or chemicals, sulfate groups play an essential role in every human body tissue.

When harmful compounds like toxins enter cells, enzymes will commonly act upon them and change their shape. One of the enzymes, called glutathione s-transferase (GST), attaches glutathione to toxic substances (like air pollutants and heavy metals). Once bound, your body can discard them. However, when the toxins are discarded, so is glutathione. Supplementing with NAC supports both normal detoxification and healthy glutathione levels within cells.

Helps keep mucus less viscous

Mucus is made of glycoproteins containing sulfur groups. In the presence of free radicals, electrons are stolen from these sulfur groups. As a result, these sulfurs will bind to other sulfurs found on nearby mucus glycoproteins to form disulfide bonds. The binding of many mucus molecules to one another creates a viscous “soup” of mucus that is hard to expel from the body.

It has been known for many decades that NAC supports the normal breakdown of mucus in the lungs. It does this by interfering with sulfur bonding. The antioxidant activity of both NAC and its end product glutathione help to keep the sulfur groups on mucus glycoproteins from sticking to one another. Additionally, NAC can bind directly to sulfur groups on mucus glycoproteins. This helps to keep them from attaching to more mucus. The end result is normal mucus viscosity (instead of a sticky mucus mess!).

NAC by Seeking Health provides 500 mg of free form N-Acetyl-L-Cysteine. The vegan-friendly capsules offer a well-absorbed supplemental form of cysteine. If you’re looking to support optimal antioxidant activity in your body, look no further than NAC capsules by Seeking Health.

NAC Vitamins
Supplement Facts

Serving Size: 1 Capsule
Servings Per Container: 90

N-Acetyl-L-Cysteine 500 mg **
**Daily Value (DV) not established.

Other Ingredients: Vegetarian capsule (hypromellose and water), microcrystalline cellulose, ascorbyl palmitate, L-leucine, and silica.

  • Suitable For: Vegetarians and Vegans
  • Delivery Method: Capsules
  • How To Store: Keep closed in a cool, dry place out of reach by children.

Free Of: Dairy, Eggs, Fish, Gluten, GMO, Peanuts, Shellfish, Soy, Tree Nuts, Wheat, Artificial Colors, Artificial Flavors, and Artificial Preservatives

How to Use NAC Vitamins

Suggested Use

Take 1 capsule daily with food and 8 oz of water or as directed by your healthcare professional. Capsule may be opened and contents mixed into juice or applesauce.


Children and pregnant, lactating, or breastfeeding women should consult their healthcare practitioner prior to use. Do not use if tamper seal is damaged. If you are experiencing acetaminophen poisoning or acetaminophen overdose, seek medical care immediately.

FAQs for NAC Vitamins

What is the purpose of each ingredient in NAC?

Ingredients Purpose
N-Acetyl-L-Cysteine Supports respiratory wellness, liver health, natural free-radical defenses, normal defenses against oxidative damage, glutathione production, detoxification, reproductive health, and a healthy immune system

Who is NAC intended for?

NAC is intended for those seeking healthy support for their liver, respiratory tract, and lungs. The benefits of NAC supplements are largely related to providing cysteine. This is the rate-limiting amino acid building block for glutathione production, one of the body’s most important antioxidant compounds.

How to use NAC?

Take 1 capsule daily with food and 8 oz of water or as directed by your healthcare professional. Capsule may be opened and contents mixed into juice or applesauce.

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What our customers say

Real reviews from real customers.

Rated 4.9 out of 5 stars
Based on 340 reviews
Total 5 star reviews: 323 Total 4 star reviews: 14 Total 3 star reviews: 2 Total 2 star reviews: 1 Total 1 star reviews: 0
98%would recommend these products
340 reviews
  • RK
    Robert K.
    Verified Buyer
    NAC (N-Acetyl-L-Cysteine)
    NAC (N-Acetyl-L-Cysteine)
    Rated 3 out of 5 stars
    38 minutes ago

    Seems to be doing as it should!!

  • JW
    Jeff W.
    Verified Buyer
    NAC (N-Acetyl-L-Cysteine)
    NAC (N-Acetyl-L-Cysteine)
    I recommend this product
    Rated 5 out of 5 stars
    1 week ago

    Very Satisfactory Product, Works Great

  • T
    Verified Buyer
    NAC (N-Acetyl-L-Cysteine)
    NAC (N-Acetyl-L-Cysteine)
    I recommend this product
    Rated 5 out of 5 stars
    1 week ago

    Can see the difference in respiratory system, good for histamine levels as well.

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