NAC | N-Acetyl-Cysteine

Which NAC supplement should I buy?

NAC (N-acetyl-cysteine or N-acetyl-L-cysteine) supplements are available in various dosages: mainly 400 mg, 500 mg and 600 mg.

But more important than the dosage is to consider the quality of the supplement. For example, it is important that as few excipients as possible are used by the manufacturer.

Additives are sometimes unavoidable for production. However some excipients may speed up the production process, but then hinder the absorption of the ingredients in the body or cause unwanted allergies. The presence or absence of excipients often determines whether a product is beneficial or not.

In addition to regular N-acetyl-L-cysteine, there is also so-called sustain NAC. In this case, the N-acetylcysteine is released into the body little by little, so it remains active in the blood longer than regular NAC.

How does NAC work?

N-acetyl-L-cysteine (NAC) is the acetylated form of the amino acid L-cysteine. Acetylation involves binding an acetyl group to a molecule.

The body can make L-cysteine itself from the amino acid L-methionine. But this conversion (synthesis) does not proceed sufficiently under certain circumstances to meet the body's needs, for example, because there are not enough building materials present. Therefore, cysteine is considered a semi-essential amino acid. Due to which additional supplementation is important.

Cysteine in turn is a precursor of the antioxidant glutathione. Through biosynthesis, glutathione is formed from the building blocks cysteine, glycine and glutamic acid.

Supplementation with NAC has the advantage over L-cysteine that it is better tolerated and less susceptible to oxidation. In addition, NAC has better absorption.

Experiences with N-Acetyl-Cysteine

There is a lot of literature to be found about N-acetylcysteine and scientific research so far has provided interesting results. Consequently, many positive comments from users of NAC can be found. The purer the product the better the efficacy.

Is NAC dangerous?

NAC is considered a safe supplement. We always recommend following the instructions for use on the label unless otherwise prescribed. Because insufficient research has been done on NAC in pregnant and breastfeeding women, it is recommended for those groups to consult with a physician before using NAC.

Do NAC supplements have side effects?

In the dosages indicated, there are no known side effects. Sometimes mild gastrointestinal problems such as nausea may occur when taken on an empty stomach. Gastrointestinal problems may also occur when taking high doses. It is recommended to reduce the dose in such a case.

Furthermore, it is reported that this acetylated form does not have the side effects that L-cysteine can.

Written by: Marcella van der Wel
Reviewed and edited by: Wouter Olthof

Updated: December 13, 2022