NAD⁺ / Sirtuins

In one line: A fuel your cells' repair-and-maintenance crews run on — and it drains as you age.

Picture this: NAD⁺ is like the electricity that powers your cellular repair crews (called sirtuins) and DNA-repair teams. Between ages 20 and 50, your NAD⁺ level roughly halves — so the repair crews get underpowered. NAD⁺ boosters aim to refill the tank.

Step by step:

1. Precursors (NMN, NR, or niacin) are converted into NAD⁺ inside the cell.
2. NAD⁺ powers sirtuins — enzymes that switch on longevity and repair programs.
3. It also fuels the teams that fix damaged DNA.
4. More NAD⁺ means these maintenance systems can work harder.

Why it matters for you: This is the most scientifically exciting longevity lever right now. Animal data is spectacular; human results look real but modest, and matter more after age 40. Resveratrol activates the same repair crews (sirtuins) from a different angle.

Turn it up: NMN, NR, niacin (the cheap but flush-causing version), exercise. Don't be fooled: the mouse results are stronger than the human results so far — this is promising, not proven, and most useful for people over 40.

The three ways to pull this pathway (each compound page has the dose, legal status and how to take it):

• Fuel-suppliers — refill NAD⁺ itself: NMN / NR and niacin (B3).
• Direct-activators — poke the sirtuins from another angle: resveratrol / pterostilbene — though whether they switch on SIRT1 directly is disputed.
• The free levers — no supplement needed: fasting, exercise and caloric restriction.