NAD is a large molecule that is not easily taken up by cells, therefore NAD itself is not administered, and nicotinamide is insufficient because it is too small and lacks other necessary components.

“It's a big molecule so that if you give a big molecule to cells, it doesn't get taken up. So we don't feed animals NAD. And we don't just feed them nicotinamide, which is the little end part of NAD because it's too small in that you need these other parts.”