NAD+ and your other medications

Why there's so little interaction data

When a drug goes through FDA approval, the manufacturer studies how it's absorbed, broken down and cleared, and how it behaves alongside commonly used medicines. After approval, side-effect reports keep accumulating. That's how a drug label ends up with a detailed interactions section.

NAD+ injections haven't gone through that process. NAD+ injections are compounded. They are not FDA-approved, FDA doesn't verify their safety, effectiveness or quality before they're dispensed, and they aren't equivalent to any approved drug. FDA's list of bulk substances nominated for 503A compounding, updated in May 2026, places NAD in Category 1, meaning it's still under evaluation. The practical result is that interaction guidance is based on biology and on experience with related compounds, not on dedicated studies.

How NAD+ relates to niacin

NAD+ is the main active form of vitamin B3 (niacin) in the body. The NIH Office of Dietary Supplements notes that more than 400 enzymes depend on it, mostly for turning food into usable energy, but also for DNA maintenance and cell signaling.

Because of that link, some 'NAD+ support' products contain niacin in one of its forms. The two main forms behave differently. Nicotinic acid commonly causes skin flushing at around 30 to 50 mg or more, while nicotinamide doesn't cause flushing. When people talk about niacin interactions, they're usually talking about high-dose nicotinic acid.

The niacin cautions worth knowing

These cautions apply to niacin supplements, not directly to injected NAD+. But if you take an NAD+ injection and a niacin-containing booster, your clinician needs to know about both.

• Diabetes medicines: high-dose nicotinic acid can raise blood sugar by worsening insulin resistance. The NIH advises that people on diabetes medicines who take high-dose niacin have their glucose monitored.
• Statins: large trials found that adding nicotinic acid to statin therapy didn't reduce major cardiovascular events and increased the risk of diabetes and digestive side effects. Major heart societies don't recommend it as an add-on.
• Tuberculosis drugs: isoniazid can interfere with the body's conversion of niacin to NAD, which is why niacin status matters in people taking it.

Theoretical concerns your clinician will weigh

Because NAD+ is involved in cell energy and DNA repair, a few situations call for extra caution even without proven interactions:

• Cancer treatment, including PARP inhibitors, which act on enzymes that use NAD+. Talk to your oncology team before starting.
• Blood thinners and antiplatelet drugs, mainly because any injection can bruise or bleed more.
• Immune-suppressing medicines, where injection-site infection risk deserves attention.
• Blood pressure medicines, since flushing and lightheadedness can occur after a dose.
• Kidney or liver disease, which affects how the body handles many substances.

Supplements are the usual blind spot

People exploring longevity care often take several supplements at once, and these are the products most often left off medication lists. A few to mention specifically:

• Other NAD+ precursors, such as nicotinamide riboside (NR) or NMN.
• Niacin in any form, including 'flush-free' products.
• Biotin, which in high doses can produce falsely high or low results on some lab tests, including thyroid tests. The NIH describes an FDA report of a falsely low troponin result in a patient on high-dose biotin.
• Hormone precursors such as DHEA or pregnenolone.
• Herbal products like St. John's wort, and supplements that affect bleeding, such as high-dose fish oil or vitamin E.

Signs to report once you start

Because interaction data are limited, what you notice after starting matters. Tell your clinician if a medicine you've taken for years suddenly seems to work differently, if your blood sugar or blood pressure readings change, or if you develop new bruising, lasting flushing, palpitations, or nausea that doesn't settle.

Also mention any new prescription, even a short course of antibiotics, and any planned surgery or procedure. A quick message through your follow-up keeps your clinician's picture current, and it's far easier to adjust a plan early than to untangle several changes later.

What to bring to your HealifyMD assessment

• A list of every prescription with doses, or photos of the labels.
• Every over-the-counter medicine and supplement, by product name.
• Any cancer history or current cancer treatment.
• Bleeding problems, kidney or liver conditions, and diabetes.
• Names of other clinicians managing your care.

Price and next steps

NAD+ Injection at HealifyMD is listed from $199/month. Pricing is confirmed at your eligibility review, there's no membership fee and the eligibility check is free. Your clinician will review your full list before prescribing and will tell you which changes, if any, to report during treatment.