[FooBarWidget]

Furthermore, we don't even know whether NAD precursor supplementation works. They raise intracellular NAD+ levels, but unclear whether they raise intercellular NAD+, which is what really matters. There are also those that say NAD+ recycling matters more than we think, and precursors don't address that.

[JumpCrisscross]

> raise intracellular NAD+ levels, but unclear whether they raise intercellular NAD+, which is what really matters

Why?

[FooBarWidget]

Urgh I made a mistake. I meant the other way around: intracellular matters more, but intercellular is easier to measure.