Move over creatine! Swanson L-Citrulline Malate kicks in Krebs cycle and beyond. It's bursting onto the fitness scene in a big way, helping people young and old break through the boundaries of personal health and fitness. L- Citrulline Malate is active in both the Krebs cycle and the Urea cycle of metabolism, which means it promotes energy production while simultaneously helping to rid the body of metabolic waste products.