Methylene blue, caffeine, and L-theanine are three powerful compounds that can provide a range of benefits for cognitive function, focus, and energy. When taken together, caffeine and L-theanine can work synergistically to provide even greater benefits for cognitive function, energy, and focus. Methylene blue can also be combined with caffeine and L-theanine for a powerful nootropic stack that can help you stay sharp and alert throughout the day.