AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, 5-aminoimidazole-4-carboxamide ribonucleoside, acadesine) is each of several interesting things. First, it’s an important pharmacological research agent, used principally as an AMPK activator. It’s a compound which has shown extremely impressive fat-loss and endurance-enhancing effects in laboratory animals. Further, it has considerable mystique resulting from at least some use by elite European cyclists. And lastly, it’s readily available from research chemical sites and is being personally tried by many, though generally as part of stacks and combined with changes in training and/or diet.