Nicotinamide mononucleotide bulk powder should be consumed daily to ensure consistency within your bodily function, with a recommended starting dose of 250mg per day. It's essential to remember that we are all individuals and tolerance will vary from person to person. The best time to take NMN is in the morning on an empty stomach, and with a dose of between 250mg and 500mg, any adverse effects are rarely felt. Some of the NMN supplement side effects that can be experienced with higher doses include abdominal discomfort, diarrhoea, flatulence, and upper respiratory health issues.