Shots N’ Shakes sweetener is aspartame. Aspartame was chosen not just because of taste but safety. Aspartame is the most-studied product in human history. It has been reviewed by the FDA three times—scrutiny imposed on no other product—ever. It has passed the safety test of every FDA-like agency in every major country in the world. In addition, recent studies confirm that “natural” sugar sweeteners like erythritol and xylitol increase clotting factors significantly. This could raise risk of heart attack or stroke and is being further studied.