Clinical Studies
The Science Behind Serene Tape
We don't ask you to take our word for it.
Every claim we make about nasal breathing is grounded in published, peer-reviewed research. Below, we've compiled the key clinical studies that explain why keeping your mouth closed during sleep changes how you feel, how you think, and how you recover — starting on night one.
These are not our studies. They belong to independent researchers, universities, and medical institutions around the world. We just believe you deserve to see the evidence for yourself.
Mouth Taping & Sleep Quality
The Impact of Mouth-Taping in Mouth-Breathers with Mild Obstructive Sleep Apnea: A Preliminary Study Lee et al. — Chang Gung Memorial Hospital, 2022 In 20 patients with mild OSA, mouth taping reduced the apnea-hypopnea index by 47% and the snoring index by 47%. Oxygen desaturation also improved significantly. Read the full study →
Study to Examine the Effect of Silicone Mouth Tape on Snoring and Mild Sleep Apnea National Clinical Trial — NCT06587256 An ongoing interventional study measuring the safety, tolerability, and impact of mouth tape on sleep quality, sleep architecture, and snoring — including the bed partner's experience. View the clinical trial →
Nasal Breathing & Nitric Oxide Production
Nasal and Oral Contribution to Inhaled and Exhaled Nitric Oxide: A Study in Tracheotomized Patients Published in PubMed, 2002 Demonstrated that nasal nitric oxide output is dramatically higher during inhalation than oral breathing, reaching levels with clinical effects in the airways. Confirms that breathing through the nose delivers significantly more nitric oxide than mouth breathing. Read the full study →
Nasal Contribution to Exhaled Nitric Oxide at Rest and During Breathholding in Humans American Journal of Respiratory and Critical Care Medicine, 1996 Found that exhaled nitric oxide was more than double during nasal breathing (141 nl/min) compared to mouth breathing (68 nl/min), confirming a substantial physiological advantage to keeping the mouth closed. Read the full study →
Nitric Oxide and the Paranasal Sinuses Lundberg, J.O. — The Anatomical Record, 2008 A landmark review showing that healthy paranasal sinuses continuously generate large amounts of nitric oxide through an inducible NO synthase. This nitric oxide acts as a vasodilator and antimicrobial agent, enhancing local defense and oxygen delivery. Read the full study →
Humming Greatly Increases Nasal Nitric Oxide Weitzberg & Lundberg — American Journal of Respiratory and Critical Care Medicine, 2002 Showed a 15-fold increase in nasal nitric oxide during humming, demonstrating the paranasal sinuses' massive capacity for NO production — a gas exchange that only occurs during nasal airflow. Read the full study →
Nasal Breathing & the Nervous System
Neural Correlates of Non-ordinary States of Consciousness in Pranayama Practitioners: The Role of Slow Nasal Breathing Frontiers in Systems Neuroscience, 2022 Confirmed that nasal breathing activates both the olfactory system and the parasympathetic nervous system via vagus nerve stimulation — while mouth breathing only activates the latter. Nasal breathing produces a measurably deeper calming response. Read the full study →
The Effect of the Nasal Airflow Reducer on Parasympathetic Activity in Adults: A Pilot Study Published in PMC, 2025 Demonstrated that controlled nasal airflow increases vagally mediated heart rate variability (HRV), supporting the mechanism that nasal breathing enhances parasympathetic tone — the "rest and digest" state critical for deep, restorative sleep. Read the full study →
Mouth Breathing & Dental Health
Alterations in Oral–Nasal–Pharyngeal Microbiota and Salivary Proteins in Mouth-Breathing Children Frontiers in Microbiology, 2020 First study to map how mouth breathing disrupts the oral microbiome. Found that mouth breathers had significantly different bacterial profiles, higher plaque levels, and increased risk of dental erosion and cavities due to reduced saliva and lower oral pH. Read the full study →
Mouth Breathing & Facial Development
Effects of Mouth Breathing on Facial Skeletal Development in Children: A Systematic Review and Meta-Analysis BMC Oral Health, 2021 A meta-analysis confirming that chronic mouth breathing causes backward and downward rotation of the jaw, steepening of the occlusal plane, and narrowing of the airway — structural changes consistent with the evolutionary regression described in James Nestor's Breath. Read the full study →
Mouth Breathing: Adverse Effects on Facial Growth, Health, Academics, and Behavior Jefferson — General Dentistry, 2010 Found that untreated mouth breathing in children leads to long, narrow faces, narrow mouths, high palatal vaults, dental malocclusion, and poor sleep — which in turn impairs academic performance and is frequently misdiagnosed as ADD. Read the full study →
Snoring, Sleep & Relationship Health
Marital Quality and the Marital Bed: Examining the Covariation Between Relationship Quality and Sleep Troxel et al. — Published in PMC, 2007 A comprehensive review finding that women living with snorers were three times more likely to report insomnia. Multiple studies confirmed that untreated sleep-disordered breathing significantly reduces marital satisfaction. Read the full study →
Impact of Obstructive Sleep Apnea Treatment on Marital Relationships Published in PMC, 2023 Found that 41% of couples with untreated sleep apnea slept in separate rooms, with snoring cited as the primary reason (86%). After treatment, 72.4% of couples returned to sleeping together — a statistically significant improvement. Read the full study →
This page is for educational purposes only. Serene Tape is not a medical device and is not intended to diagnose, treat, cure, or prevent any disease. Always consult your physician before beginning any new health practice, especially if you have a diagnosed sleep disorder.