Nasal breathing during sleep has a plausible physiological basis: nasal passages filter, humidify, and produce nitric oxide, which has vasodilatory properties. Mouth taping — using tape to encourage nasal breathing during sleep — is a low-cost emerging practice. Human evidence is limited: small studies suggest improvements in snoring and sleep quality in specific populations, but the practice has not been tested in large randomised controlled trials and carries meaningful risks for individuals with nasal obstruction.
Key Takeaways
- Nasal passages filter, warm, and humidify inhaled air; the paranasal sinuses continuously produce nitric oxide, a gas with vasodilatory and antimicrobial properties that reaches the lungs during nasal breathing.1,2
- One preliminary human study (n=20) found that mouth taping reduced snoring index and apnoea-hypopnoea index (AHI) by approximately half in selected mouth-breathing adults with mild obstructive sleep apnoea.4
- A 2025 systematic review covering 25 years of literature (10 studies, 213 patients total) concluded that evidence is sparse, effects are mixed, and two studies showed statistically significant improvement in sleep apnoea markers while others did not.5
- Mouth taping can worsen breathing obstruction in people with nasal polyps, deviated septum, severe congestion, or any condition that limits nasal airflow — making pre-screening essential before attempting this practice.5
- The mouth taping movement was popularised by James Nestor's book Breath (2020) and Patrick McKeown's work; its spread accelerated rapidly via social media, outpacing the available clinical evidence by a considerable margin.
- Partial tape placement over the centre of the lips (rather than full occlusion) is considered a lower-risk approach for those who tolerate nasal breathing at rest but wish to reduce mouth breathing during sleep.
- Magnesium glycinate contributes to normal psychological function and helps reduce tiredness and fatigue — qualities that support overall sleep quality as part of a broader sleep hygiene approach.6
Chapter 1: Nasal Breathing — The Physiological Case
The nose does considerably more than simply transport air to the lungs. The nasal cavities perform four distinct conditioning functions on every breath: filtration, warming, humidification, and olfaction. The turbinate bones create turbulent airflow that slows air passage and maximises contact with the mucous membranes, allowing the nasal mucosa to capture particulates, warm cold air toward body temperature, and add moisture before the air reaches the lower airways. When mouth breathing bypasses these structures, air arrives in the lungs less filtered, cooler, and drier — a difference with measurable consequences for respiratory function.6
Nitric Oxide: The Nasal Sinuses as a Production Site
One of the most studied aspects of nasal breathing physiology involves nitric oxide (NO). Research published in Nature Medicine in 1995 identified the paranasal sinus epithelium as a major continuous source of NO in humans, with sinus concentrations reaching very high levels.1 This NO is not simply a metabolic byproduct: it diffuses into the nasal airways and is transported to the lungs with each nasal breath, where it acts as a potent vasodilator and bronchodilator.
A subsequent human study examined the physiological effects of this nasal NO on pulmonary function. Researchers measured transcutaneous oxygen tension in healthy subjects breathing nasally versus orally and found that oxygen levels were measurably higher during nasal breathing in the majority of subjects.2 A review published in Thorax summarised the accumulating evidence that nasal NO plays a role in local host defence, regulates mucociliary activity, and functions in a manner analogous to an "aerocrine" hormone — produced in the nose and transported to a distal site of action with every inhalation.3
Mouth breathing bypasses this system entirely. The oral cavity produces negligible NO relative to the sinuses, meaning that habitual mouth breathing results in substantially less NO reaching the lungs with each breath — a difference that researchers consider physiologically meaningful, though human studies directly quantifying the clinical consequences of this difference remain limited.
Air Conditioning and Sleep Architecture
Beyond NO, the nasal route's conditioning of air temperature and humidity has direct relevance for sleep. The nasal mucosa adds both heat and water vapour to inspired air during inhalation, reducing the dry, cool airstream that can irritate the pharyngeal mucosa, increase snoring, and contribute to dry-mouth symptoms on waking. A randomised crossover trial in 37 healthy male volunteers demonstrated that restoring heated humidification to the nasopharynx measurably reduced nasal resistance and respiratory frequency while improving subjective comfort measures including dry throat and nasal obstruction.6 The authors noted that mouth breathing during sleep increases the risk of snoring and obstructive sleep apnoea by reducing genioglossus muscle activity — the tongue muscle that helps keep the airway open.
Chapter 2: The Mouth Taping Trend — How It Started and What It Claims
The modern mouth taping movement traces its popularisation primarily to two sources. James Nestor's 2020 book Breath: The New Science of a Lost Art brought mainstream attention to historical and emerging research on breathing mechanics, including a self-experimentation chapter in which Nestor and a Stanford researcher taped their mouths shut for ten days during sleep, documenting deterioration in sleep metrics before transitioning to nasal breathing. Patrick McKeown, author of The Oxygen Advantage and a practitioner of the Buteyko breathing method, has promoted nasal breathing during sleep for many years, recommending tape as a simple mechanical aid to retrain mouth breathers.
Social media amplified these ideas significantly. The hashtag #mouthtaping reportedly accumulated over 160 million views on TikTok as of early 2024. Proponents of mouth taping typically claim improvements in: snoring reduction, sleep quality, energy on waking, morning dry mouth, and even facial structure over long time periods. Commercial tape products — including SomniFix strips, Hostage Tape, and various silicone alternatives — entered the market as consumer demand grew.
It is important to distinguish what the practice claims from what available human studies have tested. Several of the most widely circulated claims, particularly those related to structural facial changes in adults and long-term improvements in sleep architecture, have not been examined in controlled human trials of adequate size or duration.
Chapter 3: What Human Research Shows — and What Is Missing
The available human evidence on mouth taping is limited in both quantity and quality. Most published studies involve small sample sizes, short durations, and populations with pre-existing sleep-disordered breathing — making generalisation to healthy adults cautious at best.
The Key Clinical Studies
The most-cited human study to date is a preliminary retrospective analysis by Lee and colleagues, published in Healthcare in 2022. Researchers enrolled 20 adults with mild obstructive sleep apnoea (OSA) who were documented mouth-breathers during sleep, with a BMI under 30 and AHI under 15 events per hour. Participants had their mouths sealed with silicone hypoallergenic tape during overnight polysomnography. The study found that both the apnoea-hypopnoea index and the snoring index were reduced by approximately half relative to baseline. The researchers noted that higher baseline AHI correlated with greater improvement — suggesting the intervention may be more meaningful in those with more significant baseline disease.4 However, this was a preliminary retrospective study, not a randomised controlled trial, and the sample was pre-selected for tolerance of mouth sealing — a factor that limits broader applicability.
A 2024 study from the Harvard group published in JAMA Otolaryngology Head and Neck Surgery examined mouth closure and airflow in 66 people with OSA. The researchers found that airflow improved with mouth closure in general, but that in people who had become dependent on mouth breathing due to nasal obstruction, mouth closure actually decreased airflow.7 This finding is clinically significant: it suggests that mouth taping is not a uniform intervention and that outcomes may depend critically on whether the individual has adequate nasal patency.
A comprehensive 2025 systematic review, using PRISMA guidelines and covering 25 years of published literature from 1999 to 2024, screened 120 articles and ultimately identified 10 that met inclusion criteria, covering a combined total of 213 patients. The review concluded that two studies demonstrated statistically significant improvement in established markers of sleep apnoea, while the remaining studies produced mixed or non-significant results. The authors highlighted the absence of large, long-term, randomised controlled trials and cautioned against interpreting the current evidence as sufficient grounds for widespread implementation.5
Understanding the Evidence Gap
Why are large RCTs absent? Several factors contribute. Mouth taping is difficult to blind — participants immediately know whether they are in the active group. Tape products are not pharmaceutical agents, making commercial funding for trials less common. The populations most likely to benefit are those who both mouth-breathe habitually during sleep and have adequate nasal patency, but identifying this group prospectively requires screening that adds to trial complexity. Researchers writing a 2024 commentary in The Journal of Physiology put it directly: the available studies do not constitute a basis for widespread self-implementation of mouth taping, particularly without medical supervision.4
This does not mean the physiological rationale is implausible. The nasal breathing physiology literature is robust, and the mechanistic logic — that redirecting airflow through the nose restores filtration, humidity, and NO delivery — is scientifically coherent. What is missing is large-scale human evidence confirming that the clinical benefits of mouth taping in unselected populations are meaningful, safe, and durable.
Chapter 4: Is Mouth Taping Safe? Who Should Be Cautious
Safety is the most critical consideration before attempting mouth taping. The practice carries no meaningful risk for individuals who breathe comfortably through the nose at rest and during light activity. For others, the risks range from discomfort to potential harm.
Contraindications and Cautions
The following groups should not attempt mouth taping without medical evaluation and explicit professional guidance:
- Nasal polyps or deviated septum: Any structural obstruction to nasal airflow makes mouth taping potentially hazardous. If the nasal route is compromised and the oral route is sealed, breathing is impaired during sleep.
- Severe or seasonal allergic rhinitis: Nasal congestion that varies by night or season creates unpredictable airflow conditions. What is patent one evening may be obstructed at 3 am.
- Moderate to severe obstructive sleep apnoea: The 2024 Harvard data indicate that individuals who have become dependent on mouth breathing to compensate for upper airway obstruction may experience worsened airflow when the mouth is sealed.7
- Anxiety about mouth restriction: Some individuals experience significant psychological distress when their mouths are covered during sleep. This is a legitimate reason not to attempt the practice.
- Active respiratory infection or congestion: Temporary nasal blockage from a cold or sinusitis is an obvious contraindication.
- Children: Available evidence on mouth taping in children is insufficient to support recommendations. Children with suspected mouth breathing should be assessed by a paediatric ENT specialist rather than self-managed.
Tape Selection and Placement
Not all tape is appropriate. Skin-safe options include: paper surgical tape (widely available at pharmacies), specifically designed mouth breathing strips (such as SomniFix, which use a porous fabric material with a central vent allowing partial oral airflow), and purpose-formulated silicone strips. Duct tape, packing tape, or any non-skin-tested adhesive should never be used. The tape should be easy to remove and should not cause skin irritation or leave residue.
Placement matters. Full horizontal sealing of the lips carries more risk than a small vertical strip placed over the centre of the lips — the partial technique. The vertical strip technique gently discourages wide-open mouth breathing without fully occluding the airway, providing a partial resistance rather than a seal. This lower-risk approach is increasingly preferred for initial experimentation.
Chapter 5: If You Want to Try It — A Safe Starting Protocol
For those who have confirmed adequate nasal patency, have no contraindications listed above, and wish to explore the practice, a cautious, gradual approach is appropriate. This section is informational only and does not substitute for medical evaluation.
Step 1: The Nasal Patency Check
Before attempting any tape during sleep, perform a simple test: sit quietly, close your mouth, and breathe exclusively through your nose for 3 to 5 minutes. If you can do this comfortably and without distress, your nasal passages are likely adequate for initial experimentation. If you find yourself reaching for air or feeling panicked, further nasal assessment is needed first — potentially addressing rhinitis, congestion, or structural factors with appropriate professional guidance.
Step 2: Daytime Familiarisation
Apply a small piece of paper tape vertically over the centre of your lips during a 20 to 30-minute period of quiet activity — reading, watching television, or sitting at a desk. This familiarises the body with the sensation and allows you to assess comfort before sleep. Remove the tape immediately if you feel distressed.
Step 3: Gradual Night-Time Introduction
Begin with the partial tape technique (a small vertical strip, not a horizontal seal). Sleep with the tape for the first few nights and note how you feel on waking: is your mouth less dry, do you feel more rested, is morning throat discomfort reduced? These subjective signals provide useful initial feedback. Keep a simple log.
Step 4: When to Stop
Discontinue immediately and consult a healthcare professional if you: experience increased snoring or worsened sleep, develop skin irritation, feel anxious or distressed about the practice, notice new symptoms of nasal obstruction, or feel that your breathing is restricted during the night. Mouth taping is an adjunct habit — not a therapy — and should be abandoned without hesitation if it is not working for you.
Chapter 6: Context in a Broader Longevity Sleep Strategy
Whether or not mouth taping becomes part of a personal sleep routine, the physiology of nasal breathing is a useful lens for understanding sleep quality more broadly. Habitually poor nasal breathing during sleep is associated with increased snoring, dry mouth, disrupted sleep architecture, and in some cases undiagnosed sleep-disordered breathing. Addressing contributing factors — nasal congestion, sleep position, bedroom humidity, allergen exposure — may improve sleep quality regardless of whether tape is used.
For those interested in sleep optimisation through supplementation, magnesium contributes to normal psychological function and helps reduce tiredness and fatigue — both of which intersect meaningfully with sleep quality. See our article on sleep optimisation (LS-13) for a broader framework. Magnesium glycinate, as included in Longevity Complete, is formulated for tolerability alongside its role in supporting normal psychological function and energy-yielding metabolism.
Breathwork practices that train nasal breathing during waking hours — including the Buteyko method and various slow nasal breathing protocols — represent a complementary approach to reducing habitual mouth breathing over time. See LS-32 for an evidence-based guide to breathwork.
Q&A: Nasal Breathing and Mouth Taping
Q1: What is the basic physiological reason nasal breathing might be better than mouth breathing during sleep?
The nasal passages filter, warm, and humidify inhaled air — functions the oral cavity does not perform. Additionally, the paranasal sinuses continuously produce nitric oxide, a vasodilatory and antimicrobial gas that reaches the lungs with each nasal breath.1,3 Bypassing the nose during sleep removes these conditioning effects and this NO delivery.
Q2: Does mouth taping actually reduce snoring?
In a small preliminary study of 20 adults with mild OSA who were documented mouth-breathers, mouth taping roughly halved both snoring index and apnoea events.4 However, this study was retrospective, non-randomised, and pre-selected participants who could tolerate mouth sealing. The evidence is promising but not sufficient to make a general recommendation.
Q3: Can mouth taping worsen sleep apnoea?
Yes, in certain individuals. A 2024 study from the Harvard group found that in people with OSA who had become dependent on mouth breathing due to nasal obstruction, sealing the mouth actually worsened airflow.7 This is a key safety point: mouth taping is not appropriate for people whose nasal passages are obstructed.
Q4: Is there a 2025 systematic review on mouth taping?
Yes. A 2025 systematic review covering 25 years of published literature (1999 to 2024) identified 10 studies meeting inclusion criteria, with a combined total of 213 patients. Two studies showed statistically significant improvements in sleep apnoea markers; results across the remaining studies were mixed. The authors concluded that the evidence base does not yet support broad clinical recommendation.5
Q5: Who should not try mouth taping?
People with nasal polyps, deviated septum, significant seasonal or chronic allergic rhinitis, moderate to severe OSA, active nasal congestion, anxiety about oral restriction, or children should not attempt mouth taping without a medical assessment. The practice depends entirely on having adequate, reliable nasal patency throughout the night.5
Q6: What kind of tape is safe to use?
Skin-safe options include paper surgical tape, commercially designed breathing strips such as SomniFix (which include a central vent), and purpose-formulated silicone strips. The tape must be hypoallergenic, easy to remove, and should not fully seal the lips when used for the first time. General adhesive tapes — duct tape, packing tape, or household tape — should never be used on skin near the mouth.
Q7: How did mouth taping become so popular?
The practice was popularised primarily through James Nestor's 2020 book Breath and Patrick McKeown's work on functional breathing. Social media amplified these ideas rapidly — the hashtag #mouthtaping reportedly exceeded 160 million TikTok views by early 2024 — creating a viral trend that spread considerably faster than the supporting clinical evidence.
Q8: Does nitric oxide from the nose actually make a measurable difference to lung function?
Human studies support this. Researchers found that oxygen levels were measurably higher during nasal versus oral breathing in six of eight healthy subjects, and that adding nasal-derived air to the breathing circuit of intubated patients increased arterial oxygen levels and reduced pulmonary vascular resistance.2 The magnitude of effect in healthy free-breathing individuals is modest, but the physiological mechanism is well-established.
FAQ
What is mouth taping and how does it work?
Mouth taping involves placing a small piece of tape over the lips during sleep to encourage the mouth to remain closed. The purpose is to redirect airflow through the nasal passages, which filter, humidify, and warm air, and which deliver nitric oxide to the lungs with each nasal breath.1 The mechanical approach does not train the body to breathe nasally; it simply makes mouth breathing more effortful during sleep.
Is mouth taping safe for everyone?
No. Mouth taping is only appropriate for people with confirmed adequate nasal patency — that is, those who can breathe comfortably through the nose at rest. People with nasal obstruction due to polyps, structural deviation, severe allergic rhinitis, or any condition that limits nasal airflow should not use mouth tape without medical advice, as it may restrict rather than support breathing during sleep.5
What does human research say about mouth taping and snoring?
The most notable human study found that mouth taping reduced snoring and apnoea frequency by approximately half in a small group of adults with mild OSA and documented mouth breathing during sleep.4 A 2025 systematic review of 25 years of literature found that only two of ten included studies demonstrated statistically significant improvements in sleep apnoea markers. Evidence remains preliminary, and large randomised controlled trials have not yet been conducted.5
What is the role of nitric oxide in nasal breathing?
The paranasal sinuses continuously produce nitric oxide (NO), a gas with vasodilatory, bronchodilatory, and antimicrobial properties.1 During nasal breathing, this NO is inhaled with each breath and transported to the lungs, where it contributes to local regulation of blood flow and airway tone. Mouth breathing bypasses the nose entirely, substantially reducing the amount of this endogenous NO that reaches the lungs.2
What is the best type of tape to use for mouth taping?
Skin-safe, hypoallergenic options are appropriate: paper surgical tape (widely available in pharmacies), commercially designed mouth breathing strips such as SomniFix that include a central vent to allow partial airflow, or purpose-formulated silicone strips. A small vertical strip over the centre of the lips is generally recommended for beginners, rather than a full horizontal seal. General adhesive or household tapes should never be used on the face.
References
- Lundberg JO, Farkas-Szallasi T, Weitzberg E, et al. High nitric oxide production in human paranasal sinuses. Nat Med. 1995;1(4):370-3. View on PubMed ↗
- Lundberg JO, Settergren G, Gelinder S, Lundberg JM, Alving K, Weitzberg E. Inhalation of nasally derived nitric oxide modulates pulmonary function in humans. Acta Physiol Scand. 1996;158(4):343-7. View on PubMed ↗
- Lundberg JO, Weitzberg E. Nasal nitric oxide in man. Thorax. 1999;54(10):947-52. View on PubMed ↗
- Lee YC, Lu CT, Cheng WN, Li HY. The impact of mouth-taping in mouth-breathers with mild obstructive sleep apnea: a preliminary study. Healthcare (Basel). 2022;10(9):1755. View on PubMed ↗
- Eguia E, Sheppard A, Bensberg M, et al. Breaking social media fads and uncovering the safety and efficacy of mouth taping in patients with mouth breathing, sleep disordered breathing, or obstructive sleep apnea: a systematic review. PLOS ONE. 2025. View on PubMed ↗
- Ito K, Yoshida T, Sakura N, Tanaka H. The effects of heated humidification to nasopharynx on nasal resistance and breathing pattern. PLOS ONE. 2019;14(2):e0210957. View on PubMed ↗
- Yang H, Huyett P, Wang TY, et al. Mouth closure and airflow in patients with obstructive sleep apnea: a nonrandomized clinical trial. JAMA Otolaryngol Head Neck Surg. 2024;150(11):1012-1019. View on PubMed ↗
