Millions of people take creatine daily for muscle performance, unaware that the supplement also crosses the blood-brain barrier and boosts neuronal phosphocreatine levels. A 2025 review in Journal of Psychiatry and Brain Science and recent clinical trials reveal significant cognitive benefits that extend far beyond athletic performance.

The brain consumes roughly 20% of the body's energy despite comprising only 2% of its mass, relying heavily on ATP for neuronal function. When neurons fire rapidly or face metabolic stress, the phosphocreatine system provides emergency energy by regenerating ATP within milliseconds. This mechanism becomes critical as aging impairs mitochondrial function, creating a bioenergetic crisis in Alzheimer's patients where brain creatine levels drop significantly.

The University of Kansas Medical Center's CABA trial tested 20 grams daily in 20 Alzheimer's patients for eight weeks, measuring brain phosphocreatine via magnetic resonance spectroscopy. A larger 2026 placebo-controlled study with 240 participants used 5 grams daily and found a 30% slowing of cognitive decline alongside increased phosphocreatine levels and improved memory test scores.

Beyond neurodegeneration, creatine supplementation improves processing speed in healthy adults under metabolic stress like sleep deprivation. The same phosphocreatine mechanism that benefits Alzheimer's patients also enhances cognitive performance during demanding mental tasks, making this widely available supplement a promising therapeutic candidate for multiple brain conditions.