NAD+ Explained
NAD+ is one of the most important molecules in your body for energy and repair. It declines with age. Here's what you can actually do about it.
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell. It's essential for energy production, DNA repair, and cellular signaling. By age 50, your NAD+ levels may have dropped by 50% or more — and this decline is linked to many hallmarks of aging.
This guide is for you if: You've heard about NAD+ and want to understand what it actually does, you're considering NMN or NR supplementation, or you want to know the best ways to support NAD+ naturally.
See the evidenceWhat is NAD+ and why does it matter?
NAD+ is a coenzyme involved in over 500 enzymatic reactions. Its two most important roles:
- Energy production — NAD+ shuttles electrons in the mitochondrial electron transport chain, which is how your cells produce ATP (energy). Less NAD+ = less efficient energy production.
- DNA repair and cellular maintenance — Sirtuins (SIRT1–SIRT7) and PARPs are enzymes that repair DNA damage and regulate gene expression. Both require NAD+ to function. When NAD+ drops, DNA damage accumulates faster.
Think of NAD+ as the fuel that powers your cellular repair machinery. When the fuel runs low, maintenance falls behind, and the signs of aging accelerate.
Why does NAD+ decline with age?
- CD38 increases — This enzyme consumes NAD+ and increases with chronic inflammation and aging. It's the biggest consumer of NAD+ in your body.
- PARP activation — As DNA damage accumulates with age, PARPs consume more NAD+ trying to repair it.
- Reduced synthesis — The enzymes that produce NAD+ (NAMPT, NMNAT) become less active.
- Increased inflammation — Chronic low-grade inflammation (inflammaging) drives CD38 upregulation.
How to raise your NAD+ levels
Exercise — Particularly aerobic exercise activates AMPK and increases NAMPT, the rate-limiting enzyme for NAD+ synthesis.
Fasting / caloric restriction — Activates AMPK and sirtuins, upregulating NAD+ biosynthesis.
Reduce inflammation — Less chronic inflammation means less CD38 consuming your NAD+.
Supplement options:
| Precursor | Dose | Cost (India) | Notes |
|---|---|---|---|
| NMN | 250–500 mg/day | ₹1,500–3,000/month | Direct NAD+ precursor, growing evidence, affordable in India |
| NR (Niagen) | 300–500 mg/day | ₹3,500–5,500/month | More human safety data, mostly imported |
| Niacin (NA) | 50–500 mg/day | ₹100–300/month | Oldest NAD+ precursor, causes flushing at higher doses |
| NAD+ IV | 250–500 mg/session | ₹8,000–15,000/session | Direct but expensive, acute benefits, not practical long-term |
For most people, NMN at 250–500 mg/day is the practical choice in India — it's affordable from domestic brands (Decode Age, Sharrets) and has good emerging evidence. Pair it with TMG (trimethylglycine, 500 mg/day) to support methylation, which NMN metabolism can deplete.
See if your NAD+ strategy is working
eterni tracks your energy markers, inflammation (hsCRP), and aging biomarkers before and after NAD+ supplementation.
Get early accessFrequently Asked Questions
Is NMN or NR better for raising NAD+?
Both effectively raise NAD+ in human studies. NMN may have a slight edge due to the Slc12a8 transporter allowing direct cellular uptake, but NR has more published long-term safety data. Practically, NMN is cheaper in India and more widely available. For most people, NMN at 250–500 mg/day is the better value choice.
Can I feel the effects of NMN?
Some people report improved energy, better exercise recovery, and clearer thinking within 1–2 weeks. Others notice nothing subjectively despite measurable NAD+ increases. The most reliable effects are subtle — better sustained energy throughout the day, slightly faster recovery from exercise, and improved sleep quality.
Should I take TMG with NMN?
It's a reasonable precaution. NMN metabolism consumes methyl groups, and chronic methylation depletion could theoretically raise homocysteine. TMG (trimethylglycine, 500 mg/day) is cheap and provides methyl donors. Many longevity practitioners recommend pairing them, though the clinical necessity isn't definitively proven.
At what age should I start NAD+ supplementation?
NAD+ decline becomes significant after 35–40. Most longevity practitioners suggest considering NMN or NR supplementation from your mid-30s onward, especially if you have signs of accelerated aging, high stress, or chronic inflammation. Before 35, focusing on exercise, sleep, and nutrition will do more for your NAD+ levels.
NAD+ metabolism in detail
NAD+ is synthesised through three main pathways: the salvage pathway (recycling nicotinamide via NAMPT → NMN → NAD+), the Preiss-Handler pathway (from niacin/NA), and the de novo pathway (from tryptophan). The salvage pathway handles ~80% of NAD+ turnover in most tissues.
NMN vs NR entry: NR enters cells via equilibrative nucleoside transporters and is converted to NMN by NRK1/2 inside the cell. NMN was originally thought to require conversion to NR for entry, but the discovery of the Slc12a8 transporter (particularly in the gut) showed NMN can enter cells directly. Both converge on the same endpoint: intracellular NAD+ synthesis via NMNAT enzymes.
CD38 — the NAD+ consumer: CD38 is a glycoprotein that increases with aging and inflammation. It's the primary NAD+ consumer in mammalian tissue, and its activity can increase 2–3x with age. This is why reducing chronic inflammation (via diet, exercise, omega-3, and anti-inflammatory supplements) indirectly supports NAD+ levels by reducing CD38 expression.
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