What are sirtuins?
Sirtuins are a family of proteins that help cells manage stress, repair and energy use, and they need NAD⁺ as fuel to work.
Think of sirtuins as a cell's maintenance managers. When times are tough, they shift the cell from "grow and spend" to "repair and conserve". But they can only work when there's enough NAD⁺ in the tank, so when NAD⁺ runs low, maintenance slips.
Why it matters for aging
Humans have seven sirtuins, named SIRT1 to SIRT7. Some work in the nucleus, the cell's control center, where they help control which genes are switched on and protect DNA. Others work inside mitochondria, the cell's power plants, fine-tuning energy production.
Sirtuins became famous because in yeast, worms and mice, boosting them could extend lifespan in some experiments, and because they depend on NAD⁺, a molecule that falls with age. That made a neat story: restore NAD⁺, reactivate sirtuins, slow aging. The individual pieces are real; whether the whole chain works in humans is still unproven.
A common myth
Activating sirtuins with supplements like resveratrol slows aging.
Sirtuins are real and important, and they're linked to longevity in some animal studies. But supplements marketed as "sirtuin activators" have not been shown to slow aging in humans, and early excitement about resveratrol faded when human results disappointed.
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Updated Nov 9, 2026 · All terms