NMN and medication: what is known, drug by drug

I have not found a published human trial that tested NMN alongside levothyroxine, warfarin, a statin, blood pressure medicine, an antidepressant or metformin. Follow the NHS guidance for your medicine, tell your GP, and ask a pharmacist before you start.

Anyone who gives NMN and your medication a "low risk" rating is reasoning from theory, and that included an earlier version of this page. What you can rely on is the NHS guidance that already exists for each medicine and a short conversation with a pharmacist. The table below puts the two side by side, for the seven medicines our customers ask about most.

What has been tested, and what the NHS says, for each medicine

Medicine	Tested with NMN?	What the NHS says about supplements	What I would do
Levothyroxine	No	Take it on an empty stomach, 30 to 60 minutes before your first meal or caffeinated drink. Calcium and iron supplements and antacids may not mix well with it.	Keep levothyroxine first thing, on its own. Take NMN later in the day.
Warfarin	No	Do not take St John's wort or vitamin K supplements. Speak to your doctor before starting anything new, and talk to your warfarin clinic.	Speak to your anticoagulant clinic before you start.
Apixaban	No	Some supplements may not mix well. St John's wort is named. Tell your doctor or pharmacist about any vitamins or supplements.	Tell your GP or pharmacist before you start.
Statins, such as atorvastatin	No. One 90-person NMN trial excluded anyone taking a statin.	Tell your doctor about any vitamins or supplements. St John's wort is named.	Tell your GP, and make sure NMN is not mistaken for niacin.
Blood pressure medicine, such as amlodipine	No	Tell your doctor about any vitamins or supplements. St John's wort is named.	Tell your GP, and keep any home blood pressure checks you already do.
Sertraline and other antidepressants	No	Some supplements may not mix well. Do not use St John's wort. Tell your doctor about any vitamins or supplements.	Ask your pharmacist before you start.
Metformin	No	Some supplements may not mix well. Tell your doctor or pharmacist about any vitamins or supplements.	Tell your GP, and keep your usual blood sugar checks.

I checked each NHS medicines page in October 2026. None of them mentions NMN. That only means NMN is too new to be listed.

Can you take NMN with levothyroxine?

Thyroid medication comes up more than any other medicine in our own search data. In the six months to October 2026, searches pairing NMN with levothyroxine or thyroid medication showed our site in Google results nearly 1,000 times, more than blood thinners, statins, blood pressure medicine, antidepressants and metformin put together.

The NHS advice for levothyroxine is about timing. Take it on an empty stomach, 30 to 60 minutes before your first meal of the day or any drink with caffeine, and at the same time each day. The NHS lists calcium and iron supplements and antacids among the things that may not mix well with it, and asks you to tell your doctor about any vitamins or supplements before you start.

NMN is neither calcium nor iron, but I would still keep it well away from your levothyroxine. The simplest arrangement is to take NMN with lunch instead of breakfast, so the two are never in your stomach together. Ask your pharmacist how far apart to take them, because the NHS page does not give a number of hours.

NMN and blood thinners: warfarin and apixaban

Warfarin is the one medicine on this page where I would not start NMN without a conversation first. The NHS tells people on warfarin not to take St John's wort or vitamin K supplements, to speak to their doctor before starting any new medicine, and to talk to their warfarin clinic for advice. Your INR is checked because small changes matter, and the clinic is the team who will spot one.

Check every supplement label for vitamin K. Our Pure NMN contains none, and neither does NMN Complex, but NMN Complex does contain trans-resveratrol, pterostilbene and quercetin, so give the clinic the full ingredient list.

For apixaban, the NHS names St John's wort as a remedy that may not mix well and asks you to tell your doctor or pharmacist about any vitamins or supplements. The same applies to NMN.

Statins: the niacin warning is about a different compound

Pharmacists sometimes see "vitamin B3" mentioned near NMN and think of niacin, which does have a history with statins. In the HPS2-THRIVE trial, 25,673 adults with vascular disease, all on statin-based treatment, took extended-release niacin with laropiprant or a placebo. It did not reduce major vascular events and it increased serious side effects (HPS2-THRIVE Collaborative Group, New England Journal of Medicine, 2014).

NMN is a different compound and it is not an authorised form of niacin in GB, so niacin's trial results cannot be moved across to it. That cuts both ways. The niacin results do not show that NMN is a problem with statins, and nothing shows that it is fine. One registered NMN trial of 90 adults aged 40 to 65 (ClinicalTrials.gov NCT04823260, sponsored by Abinopharm) excluded anyone taking a statin or nicotinic acid, so its results tell you nothing about people on a statin.

The NHS page for atorvastatin asks you to tell your doctor about any vitamins or supplements, and names St John's wort as one that may not mix well. Tell your GP you want to take NMN, by name.

Blood pressure medicine, such as amlodipine

The NHS page for amlodipine names herbal medicines such as St John's wort and asks you to tell your doctor about any vitamins or supplements before you start. If you already check your blood pressure at home, keep doing it the same way, so you and your GP have readings from before and after.

Sertraline and other antidepressants

The NHS says some medicines, remedies and supplements may not mix well with sertraline, and that you should not use St John's wort while taking it. Ask your pharmacist before adding NMN, and never stop or change an antidepressant because you have started a supplement.

Metformin

The NHS page for metformin says some supplements may not mix well with it and asks you to tell your doctor or pharmacist about any you take. If you test your blood sugar, keep doing exactly what your diabetes team asked, and do not change your metformin dose because you have started NMN.

What to take to your pharmacist

Most community pharmacists will not find NMN in their usual references, because those cover licensed medicines and NMN is sold as a food supplement. You get a far better answer if you bring the facts with you:

• the bottle, or a photo of the label, showing every ingredient and the dose
• a list of everything you take, including other supplements
• the time of day you take each one
• any monitoring you have, such as INR, thyroid function or blood sugar tests

Our Pure NMN label is short: 500mg of NMN in a plant-based HPMC capsule, and nothing else. NMN Complex adds TMG, trans-resveratrol, pterostilbene, quercetin and vitamin B12, so if that is the one you take, read the whole list out. Both labels and their lab results are on our test results page.

Why this page no longer gives each medicine a risk rating

An earlier version of this guide had a table rating each medicine as low or moderate risk with NMN. I took it down. Those ratings were reasoned from how each medicine works, with no trial of NMN alongside it to back them, and a confident label makes it easier to skip the GP conversation. I would rather tell you plainly what has and has not been tested.

If you go ahead, add one new product at a time and take the dose on the label, so that if anything changes, you and your GP know where to look. Our guide to NMN side effects covers what the human trials recorded, and the UK NMN rules guide explains how NMN is classed here.