Is breathing through your nose better?
Yes, for everyday breathing and for slow practice. Your nose filters, warms and moistens the air before it reaches your lungs, and adds a little nitric oxide made in your sinuses. Taping your mouth shut at night to force it is a different claim, and the evidence for it is poor.
Nose breathing has gone from a yoga teacher’s cue to a whole movement, with books, mouth tape and claims that mouth breathing is ruining your health. The basic idea holds up. Your nose is built to handle air and your mouth is the backup. Where it goes wrong is in the jump from that to taping your lips shut every night.
What we’d do
Breathe through your nose by default, at rest, on walks and during slow practice. Use your mouth for the long out-breath in cyclic sighing and 4-7-8, since that’s how they were taught. If your nose is blocked most nights or you snore loudly, see a doctor instead of reaching for tape.
What your nose does that your mouth doesn’t
Your nose is your body’s air handling system, with a filter, a heater and a humidifier in one. In the Cleveland Clinic’s words, “It warms, conditions and filters the air you breathe.” Air that comes in through your mouth skips all of that.
There’s a stranger job too. In 1995, researchers found that the sinuses around your nose make nitric oxide and hold it “in very high concentrations”. They thought its main job there was keeping the sinuses free of germs. A year later the same group showed that this nitric oxide “will normally reach the lungs with inspiration, especially during nasal breathing”. In six of eight healthy people, the oxygen level measured through the skin was about 10 percent higher while they breathed through the nose.
That last result was small and measured at the skin, so it doesn’t mean mouth breathing starves you of oxygen. It does show the nose is doing more than letting air through.
Mouth taping
Taping your mouth at night is the big claim built on top. In 2025, a team of researchers reviewed every study they could find on it. They found 10, all of poor quality, with a little over 200 patients in total. The benefit was small at best, and four of the studies warned of a risk of suffocation in people whose nose is blocked. If you breathe through your mouth at night because your nose is blocked, taping over the only other way in is the exact risk those studies warned about. More in mouth taping.
Nose or mouth during practice?
In the 2023 Stanford trial, cyclic sighing was taught as two breaths in through the nose and a long breath out through the mouth, and people were allowed to do it all through the nose if they liked. Six a minute and box breathing are usually done through the nose. Fast rounds are done through the nose or mouth, by the method’s own instructions.
A comfortable breath hold after a normal out-breath through your nose is also the start of the BOLT test. See what’s a good BOLT score.
The Buteyko method takes nose breathing furthest, and humming is the one thing that makes your nose’s own nitric oxide jump.
5 sources
- Cleveland Clinic, Nose: anatomy, function and related conditionsmy.clevelandclinic.org
- Lundberg JON et al., High nitric oxide production in human paranasal sinuses, Nature Medicine, 1995nature.com
- Lundberg JON et al., Nasally exhaled nitric oxide in humans originates mainly in the paranasal sinuses, Acta Physiologica Scandinavica, 1996onlinelibrary.wiley.com
- Rhee J et al., Breaking social media fads and uncovering the safety and efficacy of mouth taping, a systematic review, PLOS One, 2025journals.plos.org
- Balban MY et al., Brief structured respiration practices enhance mood and reduce physiological arousal, Cell Reports Medicine, 2023pmc.ncbi.nlm.nih.gov
