Sleep isn't something you do. It's something you allow. But when your nervous system is in fight/flight mode (sympathetic dominance), your brain treats sleep as unsafe. It's scanning for threats, keeping you alert. Melatonin can make you drowsy, but it can't override an activated nervous system.
Yoga Nidra (yogic sleep) is a state of consciousness between waking and sleeping. It's a guided deep relaxation where your body rests profoundly while a thread of awareness remains. Neuroscientists sometimes call it NSDR (Non-Sleep Deep Rest).
Research shows that during Yoga Nidra, brainwaves shift from Beta (active thought) to Theta and Delta (deep rest and sleep states), cortisol drops significantly, and the default mode network quiets — that's the part of your brain responsible for rumination and worry. In one study, 89% of participants fell asleep during practice.
A systematic review of randomised controlled trials found Yoga Nidra significantly improved sleep onset latency (time to fall asleep), total sleep time, sleep efficiency, and deep sleep stages. One RCT compared Yoga Nidra to CBT-i (cognitive behavioural therapy for insomnia — the gold-standard treatment) and found Yoga Nidra markedly improved deep sleep and reduced morning cortisol.