RME - radiant rise - Would this break a fast?

No, radiant rise wouldn’t break a fast because this is composed vitamins, extracts and powders. The ingredients do not really contain any macronutrients - fats, proteins, and carbohydrates (only 2g from dietary fiber), so they wouldn’t amount to enough calorie consumption to break a fast.

The fiber amounts to 10 calories, but breaking a fast means triggering an insulin spike which occurs around the 40-50 calorie intake mark.