# Alertness is correlated with orexin levels Orexin is a hormone which seems to be linked with alertness, as a 2007 study found that it almost negated the side-effects of sleep deprivation in monkeys. There are many ways to increase orexin levels; natural methods include exercise, fasting, eating low carb, eating protein, being lean and losing weight. --- ## 📚 References - [[@whativelearnedSimpleReasonYou2021|The simple reason you're always tired]]