N-acetyl cysteine (NAC) is the supplement form of the semi-essential amino acid cysteine. In this article we will explain what NAC is, what its benefits are, and whether there can be any side effects from taking NAC.
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What are NAC supplements?
NAC is the supplement form cysteine. Cysteine is a conditionally essential amino acid, which means that the body can produce it from other amino acids. As long as our intake of methionine and serine (both essential amino acids) is high enough, cysteine shouldn’t be an issue.
Cysteine can be is found in many high- protein foods. Chicken, yoghurt, cheese, eggs, sunflower seeds, and legumes are all good dietary sources of cysteine.
NAC, the supplement form of cysteine, acts as a precursor to glutathione, an antioxidant that can help protect the body from damage caused by free radicals.
Free radicals are unstable atoms that can break down and damage cells. Antioxidants (like glutathione) neutralise free radicals.
What are the benefits of NAC supplements
NAC increases the body’s cysteine levels and helps with production of the glutathione, an antioxidant that is produced by cysteine alongside glutamine and glycine.
Glutathione is one of the body’s most important antioxidants and helps fight cellular damage by breaking down free radicals. Alongside two other amino acids — glutamine and glycine — cysteine helps to make and replenish glutathione.
Side effects of NAC supplements
NAC is generally considered safe when used appropriately. But some people have experienced side effects including:
- Nausea
- Vomiting
- Stomach ache
- Diarrhoea
Less common side effects may include a runny nose, drowsiness, and fever.3
Take home message
Cysteine is a semi-essential amino acid can be found in many high- protein foods such as chicken, turkey, yoghurt, cheese, eggs, sunflower seeds, and legumes. NAC supplements are a good way to ensure you have a high-enough intake of cysteine, however, caution should be taken when taking it in high dosages. Consuming adequate cysteine and NAC is important for many health reasons, high among them is production of the antioxidant glutathione.
