Even though “pop health” features antioxidants as the key to long-life, most supplements aren’t that great. In contrast, N-acetylcysteine (NAC) is a potent antioxidant tool, which has numerous cognitive and physical benefits. The main benefit of NAC is as a prodrug for an amino acid called L-cysteine, which can increase the production of glutathione .
The downstream effects of added glutathione can be useful for a multitude of reasons. While it may sound trivial, NAC shows benefits in anxiety and stress through cases like nail biting and skin picking . Otherwise, there is evidence it can help with OCD, irritability, and even addiction .
For healthy adults, N-acetylcysteine can boost antioxidant effects and reduce free radicals that can cause long-term diseases.
Also Known As
N-Acetyl Cysteine, N-Acetylcysteine, N-Acetyl-L-Cysteine, N-Ac,
Editors’ Thoughts on NAC
In such an overly polluted world, anything that can reduce free radicals and increase antioxidant support is a winner in my book. Although it might be more effective to take glutathione directly, sometimes that is not always an option. My suggestion is for people to use NAC when glutathione isn’t possible (due to cost or availability).
This is a pretty useful tool from a longevity perspective. For anyone who is interested in longevity aids like nicotinamide riboside and the like, it is a good addition. Not 100% necessary, but for those with the money and desire, it can be a good boost though the subjective “feeling” will probably not be there.
Mansal Denton, Nootropedia Editor
Benefits of NAC
The number of benefit of NAC is as a tool to combat oxidative stress. Free radicals can harm DNA  and cause long-term damage that may result in diseases like Alzheimer’s, cancer etc. Free radicals are the main reason why antioxidants receive so much attention in the health space even though few antioxidant supplements are truly valuable.
Due to the antioxidant effects and boosting glutathione (what Dr. Mark Hyman calls the “mother of all antioxidants”), NAC has anti-inflammatory effects as well . In a Japanese study published in the Journal of Laboratory and Clinical Medicine, scientists concluded that NAC alone could reduce inflammation in specific tissues.
The studies on N-acetylcysteine benefits for anxiety and stress have been specific to a range of ailments that are often referred to in psychological terms. For example, people with nail biting, skin picking, or obsessive compulsive disorder (OCD) are often considered to have some psychological defect. Yet, the NAC studies show that a supplement can reduce these symptoms.
Of course, the long-term mechanisms associated with NAC are effective for chronic brain diseases. Studies on animal models show that N-acetylcysteine can reduce the rate of Alzheimer’s disease .
Finally, as far as the cognitive benefits of NAC, there seems to be neuroprotective effects especially against trauma. In one 2014 study, scientists discovered that NAC could “facilitate recovery after traumatic brain injury” . While many people may not have diagnosed TBI, any kind of concussive blows to the head can cause memory and cognitive decline.
As one would expect from a nootropic compound that aids in general antioxidant support, NAC also has benefits combatting cancer and heart disease. In a series of cancer studies, NAC was implicated in slowing the spread  and in some cases even reversing the cancer growth . In fact, it is so effective as a cancer treatment in some instances, it can protect healthy cells while leading to the death of cancerous ones.
Side Effects of NAC
Simply because NAC has some evidence to support anti-cancer benefits, one of the main side effects is that it can negate chemotherapy treatment. If you have a doctor’s ordered chemotherapy, don’t take N-acetylcysteine without some type of supervision or at least communication with your doctor.
Another side effect of NAC that is theoretical in nature is a reduction in the benefits of exercise. There are some studies showing that aerobic exercise is not influenced by NAC  and others show it can reduce fatigue , but there may still be some risks associated with NAC and exercise.
The proper NAC dosage will depend on your individual needs, but most times it is best to start around 500 – 600 mg. Make sure to take NAC without the presence of activated charcoal. Even though there are benefits of taking activated charcoal, it can reduce the effects of N-acetylcysteine.
Higher doses of NAC can cause some nausea issues, but it is a prodrug for a basic amino acid so there should not be too many health or stomach related problems.
How and Where to Buy NAC
NAC is widely available for sale in many local pharmacies and grocery stores and online. It is best to buy NAC online because you have control over the safety precautions and you can research all of the best pricing and ingredients.
Many people who are experiencing glutathione deficiencies of some sort find that NAC proves a very impactful nootropic. For many people, the NAC reviews are incredible with some people claiming that their symptoms of ADHD have been “solved” virtually overnight by larger doses of N-acetylcysteine.
In other cases, people use NAC as a source of damage control when they are drinking alcohol in heavy quantities. Most people who are using N-acetylcysteine as a tool in this way find that it is useful for both short and long-term.
Either way, make sure you take all NAC reviews with a grain of salt. As great as the NAC supplement might be, in many cases their individual experiences will be different from your own. Just make sure to do both scientific and anecdotal research before making your decisions.
Selected Community Experiences
“Hi, I've recently started taking NAC regularly at 1300mg, and I've now come to realize some of my worst ADHD symptoms seem to vastly improve.”  – throwaway12332155
“I take 4.8g NAC/day in divided doses. It changes chaotic mind to not-giving-a-fuck mind if that makes sense. Things that were previously significant are less significant and the amount of craziness (neuroticism) I experience seems to be less. I can focus and enjoy my job instead of thinking about how I and my parents are going to die or the lack of meaning in life or the cruelty of life; etc.”  – keatography
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