Guanidinoacetic acid (GAA) is a direct endogenic precursor of creatine. GAA is also a re-discovered nutraceutical that has been put forward as an energy-facilitating compound by many animal and a few human studies. Recent trials indicated that dietary GAA might have yet another role in muscle growth promotion, acting as an anticatabolic and/or anabolic compound. Our opinion paper published few days ago in Journal of Functional Foods summarizes the latest findings for advancing (or impeding) dietary GAA in skeletal muscle medicine, discussing open questions that need to be answered before the translation of supplemental GAA use from bench to bedside. Check it out!