Keeping your mouth closed while sleeping comes down to a combination of improving nasal airflow, training your jaw and tongue position, and in some cases using a physical aid like tape or a chin strap. Most people who sleep with their mouth open do so because their nasal passages aren’t clear enough, their jaw muscles relax and drop open, or both. The good news is that each of these factors can be addressed.
Why It Matters
Breathing through your nose during sleep is significantly more efficient than mouth breathing. Your nose filters, warms, and humidifies air before it reaches your lungs, and nasal breathing allows better regulation of oxygen and carbon dioxide levels in your blood. It also triggers the release of nitric oxide, a molecule that improves blood flow and oxygen delivery to the brain.
Mouth breathing dries out your oral tissues, which shifts the bacterial balance in your mouth toward species that cause cavities and gum disease. It also contributes to morning dry mouth, sore throat, bad breath, and disrupted sleep. Over time, chronic mouth breathing can affect jaw development in children and worsen snoring in adults.
Clear Your Nasal Passages First
Before trying any device or technique, make sure you can actually breathe through your nose comfortably. If your nose is partially blocked by congestion, allergies, or swelling, no amount of tape or chin straps will help safely.
A saline rinse before bed can flush out irritants and thin mucus. If you deal with seasonal or year-round allergies, treating them with an antihistamine or a steroid nasal spray can dramatically reduce nighttime congestion. Keeping your bedroom humidity at a comfortable level also helps. Dry air dries out the membranes inside your nose, causing swelling and stuffiness. A humidifier adds moisture to indoor air and can unclog a stuffy nose, reduce nosebleeds from dry membranes, and ease breathing discomfort overall.
If you consistently struggle to breathe through your nose despite these steps, a structural issue like a deviated septum or nasal polyps may be involved. Medications can reduce the swelling, but correcting a deviated septum requires surgery. It’s worth getting this evaluated if nasal breathing always feels like work.
Nasal Dilators for Better Airflow
Over-the-counter nasal dilators physically hold your nasal passages open, making it easier to breathe through your nose while sleeping. They come in two main forms: external adhesive strips that stick across the bridge of your nose, and internal silicone inserts that sit just inside each nostril.
A systematic review published in JAMA Facial Plastic Surgery found that external nasal strips increased the minimum cross-sectional area of the nasal passage by a median of 43%. That’s a meaningful improvement in airflow for people whose nostrils tend to collapse inward during breathing. Both external strips and internal dilators are inexpensive and have minimal side effects, making them a good first option to try.
Mouth Taping
Mouth taping has become one of the most popular methods for training yourself to keep your mouth closed during sleep. The idea is simple: a small strip of porous surgical tape or a purpose-made mouth tape placed vertically over your lips creates a gentle physical reminder to keep your mouth shut, encouraging nasal breathing throughout the night.
Most people who try it use a single vertical strip from just above the upper lip to just below the lower lip, leaving the corners of the mouth free. This allows you to open your mouth in an emergency. Purpose-made sleep tapes are designed with small breathing vents or weaker adhesive for added safety. Starting with daytime practice while watching TV or reading can help you get comfortable with the sensation before using it overnight.
Who Should Avoid Mouth Taping
Mouth taping is not safe for everyone. You should avoid it if you have nasal obstruction, chronic allergies, sinus infections, enlarged tonsils, a deviated septum, or heart issues. Forcing yourself to rely entirely on your nose when your nasal passages can’t handle the job can lead to significant drops in oxygen levels and respiratory distress during sleep. Even without these conditions, some people experience skin irritation, increased anxiety, or difficulty falling asleep with tape on. If mouth taping makes you feel panicked or short of breath, stop using it.
Chin Straps
Chin straps wrap around your head and cup your chin, holding your jaw in a closed position. They’re commonly recommended alongside CPAP machines for people with sleep apnea who experience mouth leak, but anyone can use them.
A study in the journal Sleep Medicine tested chin straps on 15 patients and found they reduced the amount of time spent with an open mouth from about 43% of total sleep time to 24%. They also reduced sleep disruptions. However, the results came with a significant trade-off: snoring time increased from about 7% to 24% of total sleep time. In rare cases, chin straps actually worsened breathing disturbances. The researchers noted that despite widespread use in sleep clinics, almost no peer-reviewed studies had evaluated these devices, so the evidence base is thin.
If you try a chin strap, choose one with adjustable tension so you can find a fit that keeps your jaw gently closed without pulling it back. A strap that pushes the jaw backward can narrow your airway and make snoring or apnea worse.
Train Your Tongue Position
Your tongue plays a surprisingly large role in whether your mouth stays open or closed. When you breathe through your nose, your tongue naturally rests against the front portion of the roof of your mouth, pressing gently upward. This position creates a seal that helps keep your lips together and your jaw from dropping open.
If you’ve been a mouth breather for years, your tongue may default to a low, flat position on the floor of your mouth. You can retrain this by practicing proper tongue posture during the day. Place the tip of your tongue against the ridge just behind your upper front teeth, then flatten the rest of your tongue gently against the roof of your mouth. Your teeth should be slightly apart and your lips together. Hold this position as your resting default while working, reading, or watching TV. Over weeks, the muscles strengthen and the position becomes more automatic, including during sleep.
This approach is sometimes called “mewing” in online communities, though it originates from myofunctional therapy, a set of exercises used by speech and dental professionals to correct oral posture and function.
Sleep Position and Pillow Setup
Sleeping on your back makes your jaw more likely to fall open under gravity. Side sleeping naturally keeps the jaw in a more neutral position, and many people find that switching positions alone reduces mouth breathing.
Your pillow matters too. If your pillow is too flat, your head tilts in a way that can open your airway at the mouth. If it’s too thick, it can push your chin toward your chest and restrict nasal airflow. The goal is a pillow that keeps your head and neck aligned with your spine so your jaw rests comfortably closed. For side sleepers, this typically means a firmer, slightly thicker pillow that fills the gap between your shoulder and ear. For back sleepers, a medium-loft pillow with some contouring under the neck works best.
Combining Methods for Best Results
Most people get the best results by layering several of these strategies rather than relying on one. A practical starting approach: clear your nasal passages with a saline rinse and make sure your bedroom humidity is adequate, try a nasal dilator strip, practice tongue posture during the day, and sleep on your side with a supportive pillow. If your mouth still falls open, add mouth tape or a chin strap.
If none of these approaches work after a few weeks, or if you wake up gasping, snore heavily, or feel exhausted despite a full night’s sleep, the underlying issue may be obstructive sleep apnea rather than simple mouth breathing. Sleep apnea causes the airway to collapse repeatedly during sleep, and mouth breathing is often a compensatory response. A sleep study can rule this out and point you toward more targeted treatment.