NAC for Anxiety: Research, Side Effects and Product Reviews |

NAC for Anxiety: Research, Side Effects and Product Reviews

There’s a never-ending war against the condition of anxiety and the slew of symptoms that it brings including sleeplessness, fatigue, digestive problems and mood fluctuations.

Recently, natural and low-risk forms of treatments such as supplements, natural beta blockers, essential oils and the use of biofeedback machines have become increasingly popular to help manage anxiety.

NAC, or N-acetylcysteine, is another low-risk form of treatment that can be taken in supplement form to help relieve anxiety. If you’re still looking for an alternative to expensive antidepressants or pills that could potentially be addictive.

NAC might be the solution that you’ve been searching for, so let's take a look at what all the fuss. If you don't have time to read our full article right now, check out the table below summarizing our favorite NAC supplements for anxiety.

Our Favorite NAC Supplements for Anxiety:




Our Rating



Jarrow Formulas N-A-C Sustain

Our personal favorite


NOW NAC Capsules

Budget friendly option


BulkSupplements Pure NAC

Alternative to capsule form

What is NAC and How Might it Help with Anxiety?

NAC is not a new substance – in fact, it has been used for more than 30 years as an antioxidant precursor in the treatment of paracetamol overdose.

More recently, it has become widely used in the treatment of HIV and as a mucolytic, a medicine that is used to thin mucus. Research even supports the effectiveness of NAC in treating conditions including bipolar disorder, drug addiction, autism and schizophrenia.

NAC is a modified form of the amino acid L-cysteine. It is a combination of cysteine and acetic acid, the primary component of vinegar. Stress and environmental influences often lead to requirements for cysteine beyond the body’s capacity for conversion of methionine to cysteine.

NAC helps the body produce something called glutathione, which is a powerful antioxidant that supports detoxification of the liver. Glutathione is synthesized from three amino acids and is vital to healthy cell functioning. In fact, research suggests¹ that people with depression often have a shortage of glutathione.

NAC is also anti-inflammatory and modulates the release of dopamine and glutamate levels in the brain. Glutamate is a neurotransmitter released by nerve cells in the brain.

Its primary function is to send signals between nerve cells for learning and memory. Excess levels of glutamate² are linked to toxicity of brain cells that affect cognition, mood and memory. It can cause cell damage and in severe instances, can even lead to death. NAC helps to slow down glutamate activity that causes heightened experiences of anxiety.

As an anti-oxidant, NAC balances the activity of neurotransmitters in the brain to reduce anxiety and irritability. Oxidative damage is commonly associated with stress and anxiety, and can be repaired through the intake of NAC supplements.

NAC also helps transmit and receive dopamine by keeping receptors healthy, which plays a major role in motor control and cognitive functioning.

As a supplement, NAC can help cells restore the ability to fight against damage. It works actively to restore glutathione levels and suppress inflammation when it occurs in the brain. 

Improvements in short-term and working memory are also associated with the intake of NAC supplements, as well as long-term memory formation. It interacts with iron and zinc in the body to repair tissue function and coordinate immune surveillance.

What does the Research say about NAC?

One animal study on zebrafish³ showed conclusive results that NAC prevented behavioral effects cause by stressors applied throughout the trial. Net chasing was used as an acute stressor to measure anxiety-like behavior in the zebrafish with NAC producing positive anti-stress effects.

NAC supplements also increased the amount of time zebrafish spent in the lit side of the dank in a light/dark aquarium tank test. This indicates that NAC has strong potential as a stress-reduction treatment for psychiatric disorders including anxiety.

Another study on mice⁴ observed the difference in behaviour when treated with NAC. The study focused on dark and light cycles and how the effect of anxiety in schedule changes can be reduced by NAC.

The outcomes of this research point to mild yet important contributions of NAC in lowering levels of anxiety and mood disorders. It is especially effective in prevent disruption-induced anxiety.  

A double-blind randomized trial lasting 24 weeks indicated that treatment with NAC for depressive components of bipolar disorder⁵ caused significant improvement on the Montgomery Asberg Depression Rating Scale (MADRS).

This shows good potential for NAC as a treatment for related symptoms of mood fluctuations and stress related to anxiety.

What about Safety and Side Effects of NAC?

This study indicates that oral acetylcysteine used as an antidote for paracetamol poisoning holds low risks. Adverse reactions to NAC generally result from incorrect dosing and include symptoms such as nausea, rash and very rarely, hypo-tension.

Oral intake of NAC is recommended over intravenous methods, with prolonged treatment in patients with cystic fibrosis proving safe and well-tolerated.

Clinical studies on the effects of NAC for treating irritability in children with autism also showed limited side effects.

Recommended Dosage of NAC?

Always consult your doctor about the appropriate dosage for your individual requirements, especially if you are suffering from other medical conditions or are pregnant.

Although trials indicate that NAC supplements are safe for children, it is advised to find out more from your health care practitioner before commencing with self-administered treatment.

The daily dosage amount will also vary depending on the existence of medical conditions such as bronchitis, angina, gastritis and HIV/AIDS. For general antioxidant support, 500mg daily is a good starting point.

Dosage can be increased depending on your reaction to the initial intake of NAC. It is not recommended to exceed a dosage of 1500mg per day and dosages higher than 7000mg could cause toxicity.

Prolonged supplementation of NAC could lead to a minimal decrease in levels of trace minerals found throughout the body. It is recommended to take a general multivitamin and mineral supplement.

Can you get NAC in Food?

NAC is not found naturally in food sources and must be taken in supplement form. Cysteine is however found primarily in animal protein and dairy sources such as cottage cheese, yogurt and eggs.

Secondary sources of cysteine include broccoli and red pepper, as well as plant sources such as soy beans, garlic and wheat germ. Dietary changes to increase the intake of cysteine through the consumption of natural foods show positive results.

NAC supplements are recommended to help relieve symptoms that require larger doses of cysteine.

NAC for Anxiety Product Reviews:

NOW NAC 600 mg, 250 Veg Capsules

NAC capsules from NOW are free from soy, gluten, wheat, yeast, salt, egg, sugar and shellfish, making these supplements a good choice for those with allergies and special dietary requirements. The recommended intake is one capsule taken twice daily – always check with your doctor if you have other medical conditions.

NAC capsules from NOW are great for:

- reducing anxiety and related symptoms of stress, headaches and fatigue

- breaking up mucus congestion especially in cases of bronchitis and asthma

- lifting depressive moods and easing ruminating thoughts

- increased focus and productivity throughout the day

Several customers confirm the effectiveness of NAC capsules in reducing anxious thoughts and high-level panic attacks, with some even reporting an increase in libido and creativity. NAC is thought to help increase fertility and sperm count in males.

BulkSupplements Pure NAC (N-Acetyl L-Cysteine) Powder (250 grams)

NAC is also available in powder form. This supplement from BulkSupplements contains no fillers and is lab-tested for verification and quality purposes. The product is water soluble with a slightly sour taste. It can be taken with juice to dilute the flavour.

Pure NAC powder is a good choice to take as it:

- contains no additives or unnecessary ingredients

- helps relieve general anxiety and OCD

- is cheaper to buy in powder form than capsule form

One customer testified that NAC powder helped cure depression and anxiety after years of struggling with the disorders.

Jarrow Formulas N-A-C Sustain, Supports Liver and Lung Function, 600 mg, 100 Sustain tabs

These tablets from Jarrow are produced using SUSTAIN™ Bilayer Release Technology and are vegan-friendly. This product has the distinguished feature of release technology which releases 2/3 of each dosage over a sustained period of time in the small intestine, ensuring that more NAC is absorbed into cell membranes.

The pros of NAC sustain tablets from Jarrow include:

- unique slow-release technology for better absorption

- enhanced cognition and mood stabilization

- better thought processing and improvements in sleeping disorders

Customers are very pleased with the effectiveness of Jarrow sustain tablets and showed improvements in energy levels, as well as a remarkable reduction in stress and anxiety levels.

So should you try NAC for your Anxiety?

N-acetylcysteine is a powerful antioxidant with positive results as a supplement to relieve symptoms associated with drug toxicity in paracetamol overdoses, respiratory disorders such as bronchitis, cystic fibrosis, depression, mucus relief, addiction and anxiety – to name just a few.

NAC performs an important function in repairing cells and regulating excess levels of glutamate to reduce anxiety and stress. It is relatively safe with few side effects and provides a natural and affordable alternative to expensive treatments such as antidepressants.

When taken in the right dose and preferably with a doctor’s supervision, NAC shows positive results in providing relief from anxiety and subsequent symptoms of fatigue, sleeplessness, fluctuating mood levels and panic attacks. It might just be the supplement you are looking for.