NMN / NR (NAD⁺ precursors)
Evidence: ★★★☆☆ · Status: OTC Supplement
In plain English
Age drains NAD⁺; these refill it. Which form? NR — cleanest legal status, most human data. NMN — the most-hyped, newer, a US legal grey area. Niacin (B3) — cheapest, but flushes. NAD⁺ drip — fastest and priciest, least evidence per dollar, clinic-only. Animal data is spectacular; human benefits look real but modest, and matter more after 40.
How it works
Refill cellular NAD⁺ — the fuel your sirtuins (SIRT1) and PARP DNA-repair enzymes run on. Why NAD⁺ matters and how it halves with age → the NAD⁺ & sirtuins pathway. The forms differ only in how they reach NAD⁺: NR converts to NMN inside the cell; NMN is thought to enter via the Slc12a8 transporter; niacin is the cheap classic precursor; a NAD⁺ IV infuses it directly.
Molecular target & official sources
NAMPT NAD biosynthesis (NCBI Gene) · SIRT1 sirtuin 1 (NCBI Gene) · NMN (PubChem CID 14180)
Protocol
NMN or NR 250–500 mg in the **morning** — NAD⁺ tracks your body clock and peaks in the active phase. Often stacked with pterostilbene, and with **TMG** to replace the methyl groups NAD⁺ metabolism uses up.
Watch out
NMN is a US legal grey area (FDA drug-exclusion ruling); **NR is the clean supplement.** No prescription drug is involved — but skip NAD⁺ IVs from unlicensed providers.
Bottom line
The most exciting longevity lever right now; NR the cleaner legal status, NMN the newer trials, niacin the best value. Full mechanism lives on [the NAD⁺ pathway](/pathway/12).
Helps with: Endurance · Recover Faster · Live Longer
The human evidence
A 2021 randomised trial (Yoshino et al, Science; ~25 prediabetic postmenopausal women) found 250 mg/day NMN improved muscle insulin sensitivity — a genuine but small, single-population human signal. The dramatic lifespan and healthspan results remain in animals; large human outcome trials don't yet exist.
Stacks with
Pterostilbene (sirtuin activation from another angle) and TMG / betaine (replaces the methyl groups NAD⁺ metabolism uses up).
Shares a pathway — often paired with: Niacin / NADH (Vitamin B3), Resveratrol / Pterostilbene.
Availability & where to buy
Available over the counter. Widely available OTC — e.g. iHerb (ships worldwide); in Singapore also Guardian, Watsons, GNC, Shopee / Lazada. Look for a third-party-tested / GMP mark and check the dose per serving. ~S$40–90/month for NMN; NR (Niagen) is pricier. On iHerb / Shopee — verify third-party testing, purity varies widely.
How it works: the NAD⁺ / Sirtuins pathway →
Used in these protocols
Common questions
Does NMN / NR (NAD⁺ precursors) actually work?
Human-evidence rating: 3 of 5. The most exciting longevity lever right now; NR the cleaner legal status, NMN the newer trials, niacin the best value. Full mechanism lives on the NAD⁺ pathway.
How do you take NMN / NR (NAD⁺ precursors)?
NMN or NR 250–500 mg in the morning — NAD⁺ tracks your body clock and peaks in the active phase. Often stacked with pterostilbene, and with TMG to replace the methyl groups NAD⁺ metabolism uses up.
What are the risks or side effects of NMN / NR (NAD⁺ precursors)?
NMN is a US legal grey area (FDA drug-exclusion ruling); NR is the clean supplement. No prescription drug is involved — but skip NAD⁺ IVs from unlicensed providers.
Is NMN / NR (NAD⁺ precursors) legal or approved?
Regulatory status: OTC Supplement.