The amino acid creatine is essential for muscle and brain health, and people commonly use creatine supplements to improve exercise performance and increase muscle mass. Results from a clinical trial indicate that dietary creatine may also benefit individuals experiencing post-COVID-19 fatigue syndrome (also known as long COVID). In the trial, 12 people with post-COVID-19 fatigue syndrome were randomized to take a placebo or 4 grams of creatine monohydrate per day for six months. Creatine intake caused a significant increase in creatine levels in leg muscles and across the brain at both three-month and six-month follow-ups. Creatine supplementation also led to...