Is spark powder drinks safe to have while on warfarin?

NRG drink v warfarin: Not a good idea. If you have a medical condition serious enough to require being on warfarin, you need to be very careful about your health in general and consuming anything that could interact with warfarin. There may be multiple chemicals added to that energy drink or any food supplement, which affect the warfarin. These things are not monitored by the FDA, so be careful. Best not to risk it!