NAC and medications.
NAC is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.
NAC, or N-acetyl cysteine, is a precursor to glutathione, the body's main internal antioxidant. By topping up glutathione it may support lung health and reduce oxidative stress, with Grade A evidence in that antioxidant and respiratory role. The evidence is Grade B for mood and for repetitive behaviours in autism, where Dean's RCT is the anchor, and Grade B for the liver, where an RCT in NASH showed improvements in liver tissue and enzymes. The usual dose is 600mg twice daily. The interactions worth knowing: NAC has antiplatelet effects, so it warrants monitoring alongside anticoagulants, and it potentiates the blood-pressure-lowering of nitroglycerin, which is a pairing to avoid. On the positive side, glycine and NAC together as GlyNAC tend to outperform either alone for glutathione restoration. Take it with food to limit stomach upset, and expect a harmless rotten-egg smell in urine at high doses.
Below are the 2 documented pairs we have explicitly assessed for NAC: 2 amber. The pairs cluster around 1 mechanism: Additive vasodilation. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Additive vasodilation
NAC is a sulfur-rich compound, and glyceryl trinitrate (GTN) needs sulfur groups in the body to work. Taking the two together can make GTN act more strongly, which may mean more pronounced headache and a larger drop in blood pressure than GTN alone. If you use a GTN spray or patch and take NAC, watch for dizziness, faintness on standing, or worse headaches, and tell your GP or pharmacist so they can review the timing or doses.
NAC is a sulfur-rich compound, and nitrate medicines like isosorbide mononitrate rely on sulfur groups in the body to work. Taking the two together may make the nitrate act more strongly, which can mean a more pronounced headache and a larger drop in blood pressure than the nitrate alone. If you take isosorbide mononitrate and want to use NAC, watch for dizziness, faintness on standing, or worse headaches, and tell your GP or pharmacist so they can review the timing or doses.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyWant this checked across everything you take?
This page checks the pairs you enter. The personalised Distil report goes further:
- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
See a real sample reportSomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.