Published December 21 2015
There of course are many different supplements people can take, and one of the more common ones I recommend to my patients is N-acetylcysteine (NAC). NAC is an acetylated form of the amino acid cysteine, and it is a precursor to glutathione, which plays an important role in the detoxification pathways. In fact, NAC is commonly used for acetaminophen poisoning (1) (2). And while most people with thyroid and autoimmune thyroid conditions don’t need to take NAC for this purpose, it can help with the elimination of other toxins, and has numerous other benefits.
How Does N-acetylcysteine help with liver detoxification?
As I mentioned in the opening paragraph, glutathione is an antioxidant that plays an important role in the detoxification pathways. It is synthesized by the amino acids cysteine, L-glutamine, and glycine. Cysteine has something called a sulfhydryl group, and this serves as a proton donor, which in turn is responsible for the biological activity of glutathione. And so NAC donates the cysteine, and serves as a precursor to glutathione formation.
Let’s go ahead and discuss some of the other benefits of NAC:
Chelates heavy metals. In addition to increasing glutathione levels, NAC can also act as a heavy metal chelator. It seems to be most effective in the chelation of mercury (3), and also can be effective with arsenic poisoning (4) (5) (6). However, it doesn’t seem to be effective as a chelating agent for lead (7).
Reduces inflammation and oxidative stress. There are numerous studies which show that N-acetylcysteine is effective in helping to reduce inflammation and oxidative stress. One of the main ways it accomplishes this is by increasing glutathione levels (8) (9) (10). However, NAC also helps to prevent LPS-induced pro-inflammatory cytokines (11) (12). LPS stands for “lipopolysaccharides”, and these are molecules found in gram-negative bacteria. LPS are one of the most potent immune-activating stimuli known. Earlier I spoke about how NAC can act as a chelator for certain heavy metals, and it can also prevent oxidative damage caused by heavy metals such as cadmium and aluminum (13) (14) (15).
Disrupts biofilm. I’ve spoken about biofilm in greater detail in a post entitled “What Does Biofilm Have To Do With Thyroid Health?” A biofilm is protective layer formed by bacteria and yeast. Most of the research shows that NAC is effective against bacterial biofilms (16) (17) (18) (19), but there is also evidence that it can help disrupt the biofilm of Candida (20) (21). As a result, if you are taking drugs or natural remedies to eradicate bacteria or yeast, you might want to consider adding NAC to your arsenal.
Lowers homocysteine levels. Numerous studies have shown that taking NAC can help to lower homocysteine levels (22) (23) (24). Elevated homocysteine can also be caused by a vitamin B12 or folate deficiency, or problems breaking down these nutrients. But if taking vitamin B12 and/or folate doesn’t help to lower the homocysteine levels, it probably is worth giving NAC a try.
Obesity. There is also evidence that NAC has anti-obesity effects (25) (26). Of course many other factors play a role in obesity, and so I’m not suggesting that taking NAC alone is the solution. But in addition to making the necessary lifestyle changes, taking NAC might also provide some benefits.
Dosage, Contraindications, etc.
When I recommend NAC to my patients I usually have them take 600 to 1,800 mg per day. Very rarely does someone have a negative reaction to NAC. However, there are some situations when someone probably should avoid NAC. For example, if someone has something called a CBS genetic polymorphism then they will want to avoid the consumption of foods and supplements high in sulfur, and NAC fits under this category.
In summary, N-acetylcysteine is a precursor to glutathione, and thus can help support the detoxification pathways. In addition, NAC can chelate certain heavy metals such as mercury and arsenic, it reduces inflammation and oxidative stress, disrupts biofilm, can lower homocysteine levels, and also has anti-obesity effects. As for the dosage you should take, I usually recommend 600 to 1,800 mg/day to my patients. Although most people do fine when taking NAC, those who have a CBS polymorphism might not do well when taking NAC since it’s high in sulfur.