NAC (N-Acetyl L-Cysteine) Review, Benefits, Dosage, Side Effects | November 2021

The WHO recognizes NAC as an essential medicine and it’s actually FDA approved for the treatment of Paracetamol (Tylenol) overdose.

With NAC playing such a pivotal role in medicine, it will be exciting to see how well it fares as a nootropic.

NAC (N-Acetyl L-Cysteine) Review

In this NAC (N-Acetyl L-Cysteine) review, we’ll be looking at:

  • What is NAC
  • NAC benefits
  • Recommended NAC dosage
  • Side effects of NAC
  • Where to buy the best NAC

What is NAC

NAC (N-Acetyl L-Cysteine) is a precursor to L-Cysteine, which is a precursor to Glutathione and Cysteine.

For better understanding, imagine NAC metabolizing and turning into L-Cysteine in the body and once this transformation occurs, L-Cysteine turns into Glutathione.

However, when L-Cysteine turns into Cysteine, the latter helps with Glutamate production.

Glutamate, under the right conditions, will once again turn into Glutathione.

The takeaway is that NAC turns to Glutathione (one way or another) in a flurry of complicated biochemical processes in the body.

How Does NAC Work

NAC boosts brain function in two ways.

First of all, it acts as the best antioxidant when turned into Glutathione. It’s your body’s first line of defense against free radicals and reactive oxygen species.

Its second function is modulating dopamine levels. Not just that but dopamine receptors that are depleted get renewed when NAC is introduced into the brain.

Besides these two functions, NAC also increases BDNF levels in the brain which leads to less cell death and more cell proliferation.

Lastly, it balances the levels of Glutamate in your brain, which prevents numerous psychiatric and neurodegenerative disorders.

Is NAC Legal

It’s questionable whether NAC is a dietary supplement or drug. That’s how strong of a compound it is.

As of 2021, the FDA maintains that NAC is a drug and that it should be regulated.

For that reason, you will not see it sold on places like Amazon.

However, you can still buy NAC over-the-counter in the US and many other countries.

This means that it’s absolutely legal to buy and possess NAC.

NAC Benefits

1. Increases Motivation And Drive

NAC increases dopamine levels in the brain which automatically means more motivation and drive for the person imbuing it.

Dopamine is also important for memory and reward sensitivity.

Lastly, dopamine regulates mood and pleasure, two very important markers for self-reported happiness.

2. Helps Fight Depression

In one study, over seventy people suffering from bipolar depression took 1000mgs of NAC per day for six months.

Benefits were already seen by the eight week mark using the Bipolar Depression Rating Scale.

What’s interesting about fighting bipolar depression is that one has to be very careful not to induce mania into the subjects being treated for it.

NAC not only alleviates depression but it helps balance mood, which is an essential component for treating bipolar disorder.

3. Neuroprotectant

As already mentioned, NAC turns into Glutathione in the brain, which is our most potent antioxidant present in nearly every cell.

This helps offset oxidative damage to neurons which leads to less brain damage as we get older.

It also acts as an early prevention of Alzheimer’s and Parkinson’s disease.

4. Improves Exercise Performance

While this isn’t a direct nootropic effect, exercise plays a crucial role in keeping our brain healthy and functional.

NAC has shown itself to be helpful in preventing muscle fatigue, inflammation and it even improved strength in athletes taking it.

It even helps when the person is sedentary, improving blood flow to the muscles.

5. Helps With Brain Injuries

Brain injury is a bane on both the person affected by it and his environment.

A study on more than 80 active military members who met the criteria for brain injury due to blast exposure revealed NAC reducing the severity of symptoms.

The scientists concluded that NAC is a great short-term measure for brain injuries.

However, more studies need to be done in regards to long-term effectiveness.

NAC Dosage

NAC has a half-life of around 5,6 hours, which means that you’ll have to imbue this supplement twice a day to feel the full effects.

Studies used between 600 to 3000mgs of NAC per day.

Although safety has been established, even for dosages up to 2800mgs per day, we recommend a lower dosage for a longer period of time.

NAC is a nootropic that takes time to work and that’s our main reasoning behind taking it long-term.

Our recommendation is taking 750mgs, twice a day, for a total of 1500mgs of NAC.

There is just one problem with long-term supplementation of NAC, that being the reduction of Zinc levels in your body.

This can easily be remedied by using a Zinc supplement.

NAC Side Effects

NAC has been extensively studied, just in the last ten years, 300 human studies have been completed using this supplement.

What all these studies share in common is their claim that NAC is well-tolerated and in normal dosages (up to 3000mgs per day), there are close to zero side effects.

The only real problem with NAC is the fact that it smells really bad and the taste also isn’t something to brag about.

In rare cases, NAC can cause flatulence, stomach problems, headaches and nausea.

These are all transitory effects and should go away within the first two weeks of usage.

Very rarely, you might feel inflammation, due to NAC triggering your immune system.

If the above ever happens to you, lower your dosage or consider taking Glutathione.

Glutathione is similar to NAC but is much milder on the body.

NAC VS Glutathione

As mentioned, NAC is the main precursor to Glutathione.

Some studies have shown that NAC is better absorbed by the body when compared to Glutathione.

This doesn’t necessarily mean NAC is a better supplement, since people, on average, report more side effects and bigger reactions when on NAC compared to Glutathione.

Also, since Glutathione doesn’t convert into anything in the body, it works faster.

It’s up to you which supplement you choose, consider checking out our Glutathione review for more information on this compound.

Where To Buy NAC

It’s quite hard to find pure, unadulterated NAC (N-Acetyl L-Cysteine).

We have tested hundreds of Nootropic vendors and most of them don’t satisfy our strict criteria.

Either they don’t have proper documentation (lab results) or they haven’t tested their products recently.

If you want the best NAC on the market, check out our recommended list of vendors.

Not only are these companies vetted but they also offer the most budget-friendly prices.


NAC is a must-have nootropic since its antioxidant properties, as well as its modulation of dopamine, help with numerous problems we face on a daily basis.

To conclude this NAC (N-Acetyl L-Cysteine) review, we have now learned how to use it, what dosage to take and the best place to buy it.

With that in mind, now is the perfect time to start supplementing with NAC!

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