In people

When NAD+ goes in under the skin or into a vein, blood NAD+ rises within hours and the body clears it fast, using it and turning it into its building blocks. With daily NAD+ precursors, middle-aged and older adults raise their blood NAD+ by around 60 percent and hold it there. People most often describe steadier energy through the afternoon, clearer focus and better recovery after effort. During the injection itself many feel a warm flush, a tight chest or a wave of nausea for a few minutes. That is the cell's fast response to a large NAD+ load, and it passes when the dose goes in slower or smaller.