NAC

Abbi Neale | Published 18 March 2026

What is NAC?

N-acetyl cysteine, commonly known as NAC, is a stable form of the amino acid cysteine. Once ingested, it acts as a building block for glutathione, one of the body’s most important antioxidants. Glutathione plays a central role in protecting cells, supporting detoxification pathways, and maintaining overall biochemical balance. NAC is valued because it helps maintain adequate glutathione levels, particularly when the body is under increased physiological stress.

Health Benefits:

Supports Antioxidant Action

The link between NAC and antioxidant action is well established as NAC is a stable precursor of glutathione, a potent intracellular antioxidant. Therefore, through contributing to the production of glutathione, NAC may enhance antioxidant action helping to protect the body from symptoms of oxidative stress such as an increased risk for the development of various chronic diseases and accelerated aging. Furthering this, NAC can directly conduct antioxidant activity as its its free thiol group can react with reactive oxygen and nitrogen species.

Could Aid Respiratory Health

NAC has a long history of use within clinical settings for its ability to help break down mucus, the overproduction of which can be linked to respiratory difficulties. Studies show that NAC can act as a suggests that NAC acts as a mucolytic and inhibit mucus secretion and goblet cell hyperplasia, an increase in mucus producing goblet cells in the airway. This suggests that NAC may be valuable for treating respiratory difficulties linked to the overproduction of mucus such as those linked to colds and flus.

May Contribute to Liver Function

It has been suggested that NAC may contribute to healthy liver function as the liver relies heavily on glutathione to neutralise reactive by-products and support normal metabolic processes. One study found that 3 months of consuming NAC could improve liver function in adults with non-alcoholic fatty liver disease, reducing spleen size and alanine transaminase levels.

Typical Use:

NAC is often used within supplements due to its variety of impressive heath benefits and interest in the use of this ingredient is growing as research continues to reveal the positive effects that NAC may have. Supplement products containing NAC are often formulated with the aim of supporting antioxidant respiratory health, or detoxification.