Does NAC Help Irritability?

Warning – This is Not for Beginners

N-acetylcysteine is used as the culture media for candida. Meaning that if your child has yeast overgrowth or dysbiosis, NAC is food for exactly what you don’t want to grow. In the lab, NAC is used as food – that’s what scientists call culture media – for candida.

NAC is powerful in mobilizing toxins that are stored in cells, but the body needs to be healed enough for actual detoxification to take place. Otherwise what happens is NAC starts pulling out toxins that are stored in cells, and if the body’s not functioning enough for detoxification to take place, you’re basically increasing toxicity in the body.

So again, this supplement is not for beginners. A special diet needs to have been implemented for several months before even considering NAC,

And after several months on a special diet, you might not even want to use NAC because it wouldn’t be appropriate for your child. So once again, please do not even consider NAC if you haven’t put your child on a special diet specific for their needs.

Indication Of Need For NAC

It’s used when someone has chronic problems with:

What you actually see as those four things in your child would be:

  • irritability
  • self-injurious behavior
  • hyperactivity
  • lack of focus

And then there are some contraindications. So again, please, this is not for beginners and you really need to have an efficient discussion with your healthcare practitioner before implementing any supplements, especially NAC.

What Is N-acetylcysteine?

N-acetylcysteine (NAC) is the acetyl derivative of the amino acid cysteine. NAC is considered to be generally well-tolerated and used for a variety of medical conditions for the past several decades. NAC is widely recognized for its role as an antidote of acetaminophen overdose.

So What Is NAC?

Preclinical research studies suggest that NAC may modulate pathophysiological processes such as:

  • oxidative stress
  • neurogenesis and apoptosis
  • mitochondrial dysfunction
  • neuroinflammation
  • dysregulation of glutamate and dopamine neurotransmitter systems

So you can see NAC is very important in a optimal functioning body.

NAC & Autism

So let’s get specific, NAC and autism. Maybe you’ve heard from another parent, or maybe you’ve done a Google search and you’re thinking, Oh, NAC sounds good. This is the scientific reasonings for why you might’ve heard that.

The Studies


In 2012, a DBPC study with 29 children with autism found a significant decrease in the irritability scores via the Aberrant Behavior Checklist Irritability Subscale (ABC-I) when also treated with NAC


In 2013, another DBPC study with 40 children with autism examined adding NAC to those on Risperidone and found a decrease in irritability (ABC-I) but did not affect any of the core autism symptoms.

  • Those on risperidone started out with a significantly higher irritability score.  

So it’s just really important to understand the actual patient population. This was studied in those who were already being treated with Risperidone, who were significantly more irritable.


Another double-blind placebo-controlled study with 40 children with autism found a significant decrease in the irritability and hyperactivity with NAC added to risperidone treatment.

There are a few case studies in the literature that show improvement in the core symptoms of autism with NAC treatment.

Those three previous ones, they’re relatively small. So you have less than a hundred kids in each of those studies. So it’s great to see that NAC actually has an effect on irritability, but obviously more research could be done to really investigate how NAC can improve the core symptoms of autism.

Adverse Effects

We certainly do not want to harm our children in any way. And once again, please don’t consider NAC unless your child is healing significantly already. So there’s previously reported adverse effects. They’re basically mild, but can include:

  • abdominal pain and discomfort
  • heartburn
  • flatulence
  • cramps
  • vomiting
  • diarrhea

You can see those are all related to the GI, so that’s why it’s really important to heal the GI first or as much as possible before adding NAC – if NAC is even needed after healing the GI tract. I just wanted to point out this piece of information that the largest rate of adverse effects was seen in open studies using cannabis as well.

This wasn’t particularly founded autism because there weren’t any NAC- cannabis-autism clinical trials. But the clinical trials that used NAC and cannabis saw are more adverse effects. I know many parents are either using or considering the use of cannabis.

This is the reason why it’s really important to work with a knowledgeable practitioner. You don’t want to just start giving your child supplements thinking “Oh, I heard this is good. Let me try it”. No, please do not do that. Work with someone who’s extremely knowledgeable and if you want any of these scientific references here they are.