NAD+ and NAD precursors (NMN, NR)

Plain-language summary

NAD+ is a coenzyme central to metabolism; NMN and NR are precursors sold as supplements to raise NAD+ for longevity and energy claims. They are not FDA-approved drugs.

Regulatory status

Compounded and unapproved products are not FDA-reviewed for safety, effectiveness, or quality.

Evidence snapshot

Limited. Supported mainly by small studies, early-phase trials, or indirect evidence. Conclusions are tentative.

How it works

NAD+ is required for energy metabolism and for enzymes such as sirtuins and PARPs; NMN and NR are precursors the body can convert to NAD+, and supplementation aims to counter age-related NAD+ decline.

Approved uses and researched uses

Researched uses are studied but not FDA-approved and may be off-label. This is not a recommendation to use them.

Known risks and uncertainties

Human studies of NR report good short-term tolerability, with occasional mild GI symptoms, flushing, or fatigue. Long-term safety, ideal dosing, and any real clinical benefit are not established, and supplement quality varies because these are not FDA-reviewed drugs.

Cautions and contraindications

No established clinical contraindications; caution is reasonable in pregnancy, breastfeeding, and active cancer given limited data, and supplement-drug interactions are not well characterized.

Consumer considerations

• Sold as supplements, not FDA-approved medicines, so disease or anti-aging claims are not FDA-verified.
• They can raise measured NAD+ levels, but that has not been shown to translate into longevity.
• Supplement potency and purity vary between brands.
• NMN's regulatory status shifted in 2025; NR (Niagen) has an established supplement pathway.
• Discuss with a clinician if you take other medications or have cancer history.

Questions to ask a licensed clinician

• Is there meaningful clinical evidence of benefit for my goals?
• Are there interactions with my current medications?
• Which form (NMN vs NR) has better safety and quality data?
• Are there quality-verified brands worth considering?
• What outcomes, if any, could realistically be expected?

Sources