What is NAC (N-Acetylcysteine) good for?
N-acetylcysteine, more commonly referred to as NAC, is a special formulation of the amino acid cysteine, known for its potential antioxidant and anti-inflammatory properties. Cysteine, together with glutamine and glycine, is in turn required for the production of glutathione, one of our body's most important antioxidants.
Role in mental and cognitive health
NAC also helps regulate glutamate levels, which is the brain's primary neurotransmitter. Too much glutamate or too little glutathione can have negative effects on the brain, and this is thought to contribute to substance use, and such conditions such as bipolar disorder, schizophrenia, obsessive-compulsive disorder.
It has been found that people who suffer from such conditions experience a significant improvement in symptoms and overall improved quality of life by taking NAC. In terms of substance abuse specifically, studies have shown that NAC can decrease the dependency and cravings for substances such as nicotine and cannabis, for example.
Due to the way in which it replenishes our glutathione levels and keeps our glutamate levels in check, NAC is thought to also benefit people who suffer from such conditions as Alzheimer's disease by slowing down the progression.
Role in lung health
Aside from promoting healthy brain function, another of NAC's primary uses in medicine is as an expectorant and mucolytic agent, which in simpler terms means that it breaks down and loosens phlegm in the lungs and helps your air passages decongest themselves more efficiently.
This means that NAC offers direct relief for a large array of obstructive respiratory conditions, in addition to also reducing inflammation in the bronchial tubes and replenishing glutathione levels in the lungs.
Role in reproductive health
NAC has also been known to improve male fertility. Male infertility issues are known to increase when there is not a sufficient presence of antioxidants to handle the formation of free radicals in the reproductive system, with one such condition being varicocele, an inflammation of the veins inside the scrotum.
One study showed that taking 600mg of NAC daily for 3 months after surgery improved semen integrity and partner pregnancy rate by a massive 22%, compared to group that did not take NAC.
Role in diabetes
Lastly, several animal studies have shown that NAC can help regulate blood sugar levels, and it does this by decreasing the amount of inflammation in fat cells, resulting in improved insulin resistance.
When should I take NAC?
NAC can be taken at any time of day, with or without a meal, however it is best absorbed on an empty stomach.
Also, taking NAC could potentially have an energizing or stimulating effect, so the optimal time to take it would be before breakfast, first thing in the morning, or alternatively in the early afternoon, in order to avoid any potential disturbance to your sleep schedule.
What does NAC combine well with?
NAC with glycine
Studies have shown that a combined supplementation of NAC with glycine significantly improves several aging hallmarks in older adults, such as improved glutathione levels, reduced inflammation, reduced oxidative stress, improved mitochondrial function, and also an improvement in physical function and blood pressure levels.
Definitely a combination worth considering if you are an older adult!
What are natural sources of NAC?
If you are interested in achieving your daily NAC intake through your diet, rich sources of NAC include:
- Pork
- Beef
- Chicken
- Turkey
- Tuna
- Milk
- Cheese
- Yoghurt
- Eggs
- Seeds
- Legumes
- Garlic
NAC data sources & further reading
Last updated by Asklepios on 1st February, 2025