Quick answer
NAC (N-acetyl cysteine) is a form of the amino acid cysteine with an acetyl group attached. Cysteine is found in protein-rich foods, and NAC is sold in Australia as capsules and gummies, most commonly in 600mg and 1000mg serves.
Full name
N-acetyl-L-cysteine (NAC)
What it is
an acetylated form of the amino acid cysteine
Found in food?
Cysteine is in meat, eggs, dairy, legumes and whole grains. NAC itself is made for supplements
Common serves
600mg or 1000mg per serve
Formats
capsules and gummies
What does NAC stand for?
NAC stands for N-acetyl cysteine (also written N-acetyl-L-cysteine or N-acetylcysteine). The "N-acetyl" part means an acetyl group is attached to the nitrogen atom of cysteine. This small change makes NAC a more stable compound than cysteine on its own, which is one reason it's the form used in supplements.
What is cysteine?
Cysteine is a sulfur-containing amino acid. It's one of the amino acids your body uses to build proteins, and it's also one of the three building blocks of glutathione (along with glutamate and glycine). Your body can make cysteine, and you also get it from protein foods such as chicken, turkey, eggs, yoghurt, lentils and oats.
Best value in this guide
MAYN NAC 1000mg, 180 capsules
Six months of 1000mg serves at one capsule a day.
Why do NAC capsules smell like sulfur?
Because cysteine contains sulfur, NAC naturally has a faint "eggy" or sulfur smell. This is normal and doesn't mean the product has gone off. Keeping the lid tightly closed and storing the bottle somewhere cool and dry helps. If the smell bothers you, NAC gummies are flavoured and are an alternative.
Tip: Store NAC with the lid tightly closed, away from heat and humidity, such as in a cupboard rather than above the stove.
NAC 600mg vs 1000mg: which amount?
The right amount is whatever the product label directs, or what your healthcare professional recommends. Labels in Australia commonly list 600mg or 1000mg per serve. A higher-strength capsule can mean fewer capsules per day, while a 600mg capsule gives you more flexibility.
| MAYN NAC product | Amount per serve | Format | Pack size |
|---|---|---|---|
| NAC 600mg | 600mg | Capsule | 60 capsules |
| NAC 1000mg | 1000mg | Capsule | 90 capsules |
| NAC 1000mg (value size) | 1000mg | Capsule | 180 capsules |
| NAC 1000mg Gummies | 1000mg | Gummy | 60 gummies |
How is NAC different from glutathione?
NAC provides cysteine, one of the raw ingredients of glutathione. A glutathione supplement provides the finished molecule. We cover this in detail in NAC vs Glutathione: What's the Difference?
How to choose a NAC supplement
- Check the amount per serve, not just the number on the front of the pack.
- Work out the price per serve: larger packs such as 180 capsules usually cost less per day.
- Pick a format you'll stick with: capsules have no taste; gummies are flavoured.
- Read the other ingredients if you avoid gelatin, sugar or sweeteners.
Frequently asked questions
Is NAC the same as cysteine?
Not exactly. NAC is cysteine with an acetyl group attached, which makes it more stable. It is the form of cysteine most commonly sold as a supplement.
Is NAC vegan?
NAC itself is made in a lab and is not animal-derived. Whether a product is vegan depends on the capsule shell and other ingredients, so check the label.
Can I buy NAC in Australia?
Yes. NAC is available in Australia as capsules and gummies. MAYN NAC ships from Australia with free shipping on orders over $75.
When should I take NAC?
Follow the directions on the product label. If you're unsure, ask your pharmacist or doctor.
Keep reading
This article is general information only and is not medical advice. Always read the label and follow the directions for use. Dietary supplements should not replace a balanced diet. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak with your doctor or pharmacist before taking a new supplement.
