Does mouth taping actually improve deep sleep?

Early data from our sleep study suggests yes — participants wearing mouth tape showed a measurable increase in deep sleep percentage compared to their no-tape nights. The mechanism makes physiological sense: nasal breathing activates the parasympathetic nervous system, promotes nitric oxide production (a vasodilator), and maintains steadier oxygen saturation — all factors that support deeper, more restorative sleep. We're collecting data from 500+ participants with Oura, Apple Watch, and WHOOP to build statistically significant results. Early access to findings is available to study participants.