NAD+ 101: What It Is, Potential Benefits, Risks & the 2025 NMN Update

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme every cell uses for energy production, DNA repair, and cell signaling. Interest has surged around supporting NAD+ levels with lifestyle strategies and precursors like NR or NMN. Here’s what the science actually shows, what’s still emerging, and what changed with NMN’s status in 2025.

What is NAD+ and why does it matter?

NAD+ shuttles electrons (redox reactions) and serves as fuel for enzymes involved in DNA repair and cellular stress responses (e.g., sirtuins and PARPs). Adequate NAD+ is linked to mitochondrial function, metabolic homeostasis, and healthy aging biology. ^{1, 5, 10, 15}

Do NAD+ levels change with age?

Multiple reviews report age-related declines in NAD+ and related pathways (e.g., SIRT1/NAMPT). While cause-and-effect in humans is complex, this decline is a major rationale behind NAD+ “boosting” strategies. ^{5, 12, 13}

Ways to support NAD+: lifestyle first

• Exercise: Human studies and reviews show training can upregulate NAMPT and pathways tied to NAD+ and mitochondrial biogenesis. ^{4, 17, 6}
• Sleep & circadian rhythm: The circadian clock and NAD+/sirtuin system are intertwined; consistent sleep/wake timing supports these networks. ^{3, 12, 5}

Supplements & therapies: what the evidence shows

Niacinamide/Niacin (vitamin B3) & precursors

NR (nicotinamide riboside): In a 6-week trial of middle-aged/older adults, NR was well-tolerated and significantly increased blood NAD+ levels; downstream clinical outcomes were exploratory. ^{2, 6}

NMN (nicotinamide mononucleotide): A placebo-controlled study in overweight/obese women with prediabetes found improved muscle insulin sensitivity with NMN vs. placebo, while other trials/meta-analyses show consistent NAD+ increases but mixed clinical outcomes overall. ^{7, 14, 12}

IV NAD+ & IV NR

Claims for IV NAD+ are ahead of the data. A 2024 pilot of intravenous NR reported acceptable short-term safety, but controlled evidence for clinical benefits of IV NAD-related infusions remains limited. ⁹

Safety & who should avoid NAD+ boosters

• General tolerance: NR and NMN have shown favorable short-term safety in trials and reviews, though long-term outcomes are still being studied. ^{4, 14}
• Niacinamide/niacin: High-dose niacin can cause flushing; very high doses of niacinamide have been linked to liver enzyme elevations — stay within clinician-guided ranges.
• Pregnancy/breastfeeding & active cancer care: Always consult your oncology/OB team before starting any NAD+-modulating regimen.

2025 regulatory update: is NMN legal as a supplement?

Yes — as of Sept 29, 2025, FDA letters responding to citizen petitions state that NMN is not excluded from the definition of a dietary supplement because it was marketed as a supplement in the U.S. prior to drug investigations. (This reverses the agency’s 2022 position.) ^{8, 16}

Note that this decision addressed status, not efficacy claims. Standard supplement rules still apply (no disease-treatment claims, good-manufacturing practices, etc.).

How Mint Med can help

• Personalized guidance: We review your goals, meds, and labs to decide if NAD+ support fits — and if so, how (lifestyle, nutrition, or precursors).
• Evidence-aligned approach: We set realistic expectations, track outcomes, and prioritize safety.

Medical disclaimer: This article is educational and not medical advice. Supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult a licensed clinician about your specific situation.