The advice on whether or not to take NAD+ if you have or had cancer can vary and depends on various factors, including the type and stage of cancer, current treatments, and overall health status. It is important to consult with your healthcare provider before starting any new treatment, including NAD+ therapy, to ensure that it is safe and appropriate for you. Your healthcare provider can review your medical history and current health status to determine if NAD+ therapy is an appropriate option for you and, if so, what dosage and duration would be most beneficial.