Skip to main content

Can I take 90 and Nac together?

Drug interaction guide

There are no known significant interactions between N-acetylcysteine (NAC) and paracetamol (often referred to as '90' in certain contexts or misreadings of '500'mg tablets). In fact, NAC is the specific medical treatment used in hospitals to treat paracetamol overdose. When taken at normal, recommended doses, they do not interfere with each other.

Continue reading below

Why this happens

NAC works by increasing the levels of glutathione in the liver. Glutathione is a substance that helps neutralise a toxic byproduct produced when the liver breaks down paracetamol. Because they work on the same pathway in a helpful way, there is no negative interaction.

It is safe to take these together at recommended doses. However, you must strictly limit or avoid alcohol when taking paracetamol, as the combination increases the risk of liver damage. Always follow the dosage instructions on the packaging.

Continue reading below

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
flu eligibility checker

Ask, share, connect.

Browse discussions, ask questions, and share experiences across hundreds of health topics.

symptom checker

Feeling unwell?

Assess your symptoms online for free

Sign up to the Patient newsletter

Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.