Mouth Taping for Sleep: What the 2025 PLOS One Review of 10 Studies Really Showed

Nose-breathing at night is a genuinely good idea. The nose filters, warms and humidifies incoming air, keeps the mouth from drying out, and for some people it quietly reduces snoring. From there, TikTok took a straightforward physiological fact and turned it into a nightly ritual with a strip of tape across the mouth — now sold as the one-weird-trick for jawlines, deeper sleep and better mornings.

The claim and the practice are two different things. In May 2025, a Canadian ENT team at Western University published the first proper systematic review of mouth taping in PLOS One. If you have been circling this trend, their findings are worth reading before you buy a roll of hypoallergenic tape.

What the 2025 review actually pooled

Rhee, Iansavitchene, Mannala, Graham and Rotenberg combed the literature for studies of oral occlusion during sleep in people with mouth breathing, sleep-disordered breathing or obstructive sleep apnea (OSA). They found ten studies, 213 participants in the abstract (233 in the results section, a discrepancy the paper does not reconcile), spanning cross-sectional work, one randomised controlled trial, and a few cohort and crossover designs. Every single study was rated poor quality on the Newcastle-Ottawa Scale.

That matters. A "systematic review" sounds authoritative; this one is really a careful audit of a very thin evidence base. The authors' core conclusion is a hedge, not a verdict: current data does not support oral occlusion as a sound clinical intervention for the general population with sleep-disordered breathing.

Does mouth taping help sleep apnea?

This is where most of the viral claims land, and where the review's findings are narrowest.

Of the six studies that measured the apnea-hypopnea index (AHI) as a primary outcome, only two — Lee et al. and Huang et al. — showed a statistically significant drop after oral occlusion. Both studies restricted enrolment to people with AHI below 15, i.e. mild OSA. Labarca et al. found an AHI reduction only when mouth taping was combined with a mandibular advancement device, not with taping alone. Lee et al. explicitly flagged that mouth taping may be harmful rather than helpful in moderate-to-severe OSA.

In other words: a small benefit, in a specific mild subgroup, in two small poor-quality trials. That is not a case for recommending taping to anyone who snores.

What about snoring and mouth-breathers?

The nuance here is the interesting part. Snoring index and oxygen desaturation index improved in a couple of studies, but the clinical significance was not established and the outcome appeared in two trials or fewer. In the Jau et al. study, intermittent "mouth puffing" during taping — essentially the tape failing to seal properly — was associated with higher AHI and more oxygen dips.

Yang et al. produced the finding that complicates the trend most clearly: closing the mouth increased airflow in people with moderate mouth breathing, did nothing in people with near-zero mouth breathing, and actively reduced airflow in people with high mouth breathing. The idea that forcing nasal breathing is universally good falls apart the moment someone's nose cannot do the job.

The safety story most of the videos skip

Four of the ten studies flagged a risk of asphyxiation or regurgitation when the mouth is sealed in the presence of nasal obstruction. Most studies deliberately excluded people with nasal obstruction — which means the people most at risk of harm in real life are largely missing from the evidence base. A colds-and-allergies-prone Singaporean sleeping in air-conditioning, with dust mites and perennial rhinitis in the mix, is exactly the person these trials screened out.

As the authors wrote, "there are potential serious detrimental health outcomes to those with nasal obstruction" who use mouth tape. It is not a boutique concern. If the only reason your mouth falls open at night is that your nose cannot keep up, taping does not fix anything; it moves the problem.

What the trend promises vs. what the review found

So where does this leave someone who wakes with a dry mouth?

The honest answer is: look at the cause, not the symptom.

If you snore loudly, wake unrefreshed, or your partner has heard you stop breathing, the right next step is a doctor's assessment — not a self-managed intervention over an undiagnosed condition. OSA is common, often missed, and sits downstream of blood pressure, metabolic and cognitive risk; a strip of tape over an untested airway is a bad trade.

If your nose congests at night — allergies, deviated septum, perennial rhinitis, a dry air-conditioned bedroom — the fix is addressing that: nasal saline rinses, allergy management with your GP, a bedside humidifier if your room is actively dry, side-sleeping instead of back. Several of these are boring and well-evidenced; none require tape.

And if you are a generally healthy person without snoring, without obstruction, who still wants to encourage nasal breathing, the review's authors are not telling you taping is forbidden — they are saying the current evidence does not support recommending it, and that the harm pathway (nose blocks unexpectedly, mouth cannot open) is real. That is a different conversation than TikTok has been having.

A note on the quality floor

The authors rated all ten studies poor quality. They called for higher-quality research, which is the standard scientific-review line, but worth taking literally here: there is no large randomised trial of mouth taping for sleep that would warrant the current level of social-media confidence. If someone shows you a before-and-after and tells you the science is settled, the systematic review of the actual science politely disagrees.