Does mouth tape increase blood oxygen?

Mouth tape didn't raise average blood oxygen in the one study that measured it, but it did smooth out the dips. In the 2022 Healthcare study, median oxygen saturation stayed at 95% at baseline and on a taped night a week later, while the number of oxygen drops an hour fell and the lowest reading of the night rose. That's a more specific, and more interesting, result than "tape boosts your oxygen."

Below is what the studies found, what normal overnight oxygen looks like, and how far you can trust the oxygen number on your watch or ring.

What does SpO2 mean on a sleep tracker?

SpO2 is your oxygen saturation as measured by a pulse oximeter, a percentage that tells you how much oxygen your blood is carrying. The FDA describes a pulse oximeter as a device that uses light beams to estimate blood oxygen and pulse without drawing blood. Watches and rings use the same idea, shining light through the skin.

Two related numbers show up in sleep reports and studies. Average saturation is your typical level across the night. An oxygen desaturation index, or ODI, counts how many times an hour your oxygen dips. The Healthcare study defined ODI as the average number of desaturation events per hour, and counted a hypopnea, a shallow breath, only when it came with an oxygen drop of at least 3%. A night can have a normal average and still have plenty of dips, which is why both numbers matter.

Does mouth tape increase blood oxygen?

Mouth tape didn't increase average blood oxygen in the only study that reported it. In the 2022 Healthcare study of 20 mouth breathers with mild sleep apnea, median oxygen saturation was 95% before taping and 95% on a taped night a week later. The 2025 PLOS One systematic review confirmed this was the only mouth taping study to assess mean oxygen saturation.

The dips told a different story. In the same study:

• The oxygen desaturation index fell from 8.7 to 5.8 dips an hour, a 36% drop.
• The lowest oxygen reading of the night rose from 82.5% to 87%.
• Time spent below 90% oxygen went from a median of 1% of the night to 0%, though that change wasn't statistically significant.

Snoring fell too, by 47%, and 13 of the 20 people halved their snoring. The study was small, had no control group and measured each person on just two nights a week apart. These are study results in people with mild sleep apnea, and mouth tape isn't a sleep apnea treatment. Our mouth taping research tracker lists every study if you want the full picture.

What did other studies find about oxygen dips?

A 2023 study in Nature and Science of Sleep found mouth tape improved oxygen dips in about half the people it tested. Researchers in Taiwan gave 71 adults a two-night home test, sleeping normally the first night and with their mouths taped the second, using a validated fingertip pulse oximeter and a sensor that detects air puffing out through the lips.

Of the 58 people analyzed, the oxygen desaturation index improved with tape in 30 and didn't improve in 28. The group that didn't improve had more "intermittent mouth puffing," where air escapes through taped lips in bursts during breathing. People with severe sleep apnea had the most mouth puffing of all. This was a single taped night, so it shows how varied the response can be rather than a reliable average.

What is a normal oxygen level while you sleep?

A normal oxygen saturation is 95% to 100%, according to MedlinePlus and Cleveland Clinic, and it drifts slightly lower at night. People with lung conditions such as COPD may normally run lower, and so may people who live at high altitude, where there's less oxygen in the air.

The overnight dip is small. A 2023 study pulled 72 million readings from 33,080 smartwatch wearers and found oxygen followed a daily rhythm, lowest near midnight and highest near noon, with overnight readings averaging 0.8% lower than daytime ones. So a night average of 94% or 95% on a wearable isn't automatically a warning sign.

For home oximeters, MedlinePlus and Cleveland Clinic give the same thresholds: contact your provider if your reading is 92% or lower, and seek immediate medical attention if it falls to 88% or lower.

How accurate is the oxygen reading on a watch or ring?

The oxygen reading on a watch or ring is a reasonable estimate when your levels are normal and much less reliable when they're low. A 2024 review of reviews found one popular watch model differed from conventional pulse oximeters by up to 2.0% on average, but with some readings ranging from about 6% too low to 6% too high.

Low readings are where it matters most, and where devices struggle. A 2026 lab study lowered volunteers' oxygen under controlled conditions and compared a smartwatch and a clinical-grade finger oximeter against arterial blood. Both overestimated oxygen. Below 88%, the finger device had an average error of about 3.5 percentage points and the watch about 5.8, both beyond the FDA's accuracy threshold for those conditions. The authors warned the watch could miss real low oxygen near 88%.

Accuracy also varies between devices and studies, so treat a single night's number as a rough guide. Our guide to snoring apps and sleep trackers covers the other things these devices estimate.

Does skin tone affect pulse oximeter readings?

Skin tone can affect pulse oximeter readings, and the FDA has been working on the problem for several years. The FDA says multiple factors can affect accuracy, including poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use and fingernail polish. MedlinePlus lists darker skin pigmentation, cold skin and artificial nails among them too.

In January 2025 the FDA issued draft guidance proposing new testing and labeling recommendations for medical pulse oximeters, part of an effort to improve how well they perform across skin tones. That guidance covers pulse oximeters used for medical purposes, so it doesn't tell you how accurate a particular wearable is. The FDA's own advice for home use is simple: don't rely only on a pulse oximeter, keep track of how you feel, and contact a health care provider if you're worried about a reading.

When should low oxygen send you to a doctor?

Low oxygen readings should send you to a doctor, not to mouth tape. Cleveland Clinic lists sleep apnea among the common causes of low blood oxygen, alongside heart and lung conditions. If your wearable keeps flagging dips, or a home oximeter reads 92% or lower, book an appointment.

The same goes for symptoms. MedlinePlus lists bluish lips or nails, trouble breathing, chest tightness and a fast heart rate as signs of low oxygen, and a doctor can arrange a proper sleep test if sleep apnea is a possibility. Our guide to sleep apnea and mouth breathing explains how the two overlap, and what AHI means explains the number a sleep test reports.

Mouth tape is for people who can breathe comfortably through their nose and want to stop mouth breathing at night. Our page on whether mouth taping is safe covers who should skip it. We don't recommend mouth tape for children.

How should you read your oxygen data with mouth tape?

Read your oxygen data with mouth tape as a trend across weeks, not a score for one night. Because a wearable can be off by a couple of percentage points, a one-point rise on a single night means very little. A steadier pattern across a week or two is more meaningful.

A fair comparison looks like this:

• Wear the same device, on the same wrist or finger, snug enough to keep contact.
• Log a week or two without tape, then the same with tape, keeping bedtime and alcohol habits steady.
• Compare averages and the count of flagged dips, not single nights.
• Note snoring and morning dry mouth as well, since those are the outcomes research has measured most often.

Our guide to tracking your mouth tape results has a simple log you can copy.

Our pick (paid partner): Titan Bamboo Silk Mouth Tape

If you want to run your own before-and-after, our pick is Titan Bamboo Silk Mouth Tape. We haven't tested or ranked mouth tapes ourselves, and no tape has been shown to raise average oxygen; this is our recommendation based on how Titan describes its tape.

Titan says the strip is bamboo silk, which it describes as soft, breathable and moisture-wicking, with no printed logo or ink on the side that touches skin. It comes in one oval size, 76 by 38 mm, worn horizontally across the lips, and Titan suggests 20 to 30 minutes of daytime practice before the first night. It says every batch is third-party tested and certified PFAS-free, and its 30-night guarantee refunds you if your sleep isn't better after 30 nights.

Read next

• Does mouth tape improve deep sleep or REM?
• How to tell if mouth tape is working
• Mouth taping myths

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.