@Hayley Foster I don't think it makes me tired. It's just the initial 1-2 hours is a little uncomfortable, but overall I do feel more productive on days I inject. I wear an Oura ring but not as much as I should. Haven't noticed anything particular in terms of Oura ring changes after NAD+. That said, I don't wear or pay attention to the Oura ring as much as I should. The main thing I use the Oura ring for is for tracking my walking steps.