Starting dose for NAD+ and IM

Hey, I just received my NAD 500mg and am planning to start it tomorrow. That being said I am seeing starting doses all over the place . The most common is 50mg-100mg. However I have also heard someone tell me they did 10mg and more than that made them feel like they were gonna die. I was just trying to hear more personal experience with starting doses . As of now I was planning to start at 25mg. Also, I have heard plenty people do IM instead of subq. This is doable with water based buffered NAD correct ? Any experience with that instead of subQ? Thanks in advance