Waking with a dry mouth means your mouth lost moisture overnight, either because you breathed through it or because you made less saliva. Common causes include a blocked nose, allergies, alcohol, dehydration and some medicines [1][2]. Treat the cause first; if it keeps happening, or you snore loudly, see your GP or dentist.
This guide is general information, not medical advice. If you snore loudly, stop breathing or gasp in your sleep, or have a breathing or sleep condition, talk to your doctor before trying mouth tape.
Why you wake up with a dry mouth
You wake with a dry mouth when saliva drops or air dries your mouth overnight, and there are plenty of reasons either can happen. It's common: about 1 in 3 adults report a dry mouth at some point [2]. healthdirect lists these risk factors and causes [2]:
- Medicines, including antihistamines, decongestants, antidepressants, blood pressure medicines, painkillers and diuretics.
- Drinking a lot of alcohol or soft drink, and not drinking enough water.
- Snoring, anxiety or stress, and older age.
- Health conditions such as diabetes and Sjögren's syndrome, and treatments such as chemotherapy and radiotherapy.
Breathing through your mouth during sleep, often because your nose is blocked, can dry it out too, and smokers produce less saliva than non-smokers [1]. If a medicine might be the cause, don't stop or change it without talking to your doctor [2].
Why some people sleep with their mouth open
Often it's because breathing through the nose is hard, although for some people it's simply habit. The Sleep Foundation lists these common causes [3]:
- A blocked nose, from a cold or from ongoing problems such as allergies or nasal polyps.
- A deviated septum, where the wall between the nostrils is bent.
- Obstructive sleep apnoea, for which mouth breathing can be a sign.
- Swollen adenoids, a common cause in children.
- Teeth that make it hard to close the mouth fully, or plain habit.
What mouth breathing does overnight
It dries the mouth and makes it more acidic. In a small study, 10 healthy adults wore a nose clip on some nights to force mouth breathing: the mean pH inside the mouth during sleep fell to 6.6, compared with 7.0 on normal nights [4]. A drop like that has been proposed as a factor in tooth erosion and decay [4]. Regular mouth breathing is also linked with a sore throat, bad breath and cracked lips in the morning [3]. An occasional night of mouth breathing during a cold usually isn't significant [3].
How to stop mouth breathing at night
Start with your nose, because you can't breathe through it comfortably if it's blocked.
- Treat congestion. A saline spray or rinse before bed, allergy treatment your pharmacist or GP recommends, and a bedroom humidifier can help [3][2]. See an ear, nose and throat specialist if congestion is constant [3].
- Sleep on your side. Side sleeping may open the nasal airway for some people [3].
- Try a nasal strip. Results in studies are inconsistent, but strips are simple to try [3]. Our guide to mouth tape vs nasal strips compares the options.
- Without tape: a chin strap is designed to keep the mouth closed, though research on it is limited [5].
- Mouth tape only with a clear nose. Skip it with a blocked nose, untreated sleep apnoea, asthma or COPD unless your doctor agrees, an anxiety or panic disorder, after heavy drinking or if you might vomit, and never use it on children [6].
If you do try mouth tape, choose one made for skin, ideally with a vent, and read is mouth taping safe? first. pretty sleepy. is a cosmetic lip-care product; it isn't a treatment for dry mouth, and it isn't intended for snoring or sleep apnoea.
Does mouth tape help?
It hasn't been properly tested for dry mouth. The Sleep Foundation lists less dry mouth among the anecdotal claims for mouth taping, alongside fresher breath and fewer cavities [6]. The research that exists is small and focused on sleep apnoea, and a 2025 systematic review found mixed results and flagged a potentially serious risk of harm for people who tape without checking first [7]. Our does mouth taping work? guide goes through the studies.
When to see a doctor or dentist
See your GP if dry mouth bothers you or keeps happening, and keep up regular dental check-ups, because dry mouth greatly raises the risk of tooth decay and gum disease [2]. Talk to a doctor sooner if you [3]:
- often wake with a dry mouth, sore throat or headache;
- have a nose that's always blocked;
- snore loudly, gasp or stop breathing in your sleep;
- feel tired or foggy during the day;
- notice sore gums or tooth decay.
For a child who breathes through the mouth and snores, see a doctor promptly [3].
FAQs
Can I use mouth tape with a blocked nose?
No. Mouth tape is only for people who can breathe comfortably through the nose, so skip it whenever you're congested [6].
Is nose breathing better than mouth breathing?
Your nose filters, warms and humidifies air and your mouth doesn't, as allergist Professor Connie Katelaris explained to the ABC [8]. That doesn't mean taping your mouth shut is the fix; if your nose is blocked, treating that comes first.
Does mouth taping help dry mouth?
It hasn't been studied directly [6]. Treat the cause, and see your GP or dentist if it persists. For more, see our mouth tape FAQ.
pretty sleepy. is a cosmetic lip-care product, not a medical device. If you snore loudly, gasp or stop breathing in your sleep, or have a breathing or sleep condition, talk to your doctor before using any mouth tape.
Sources
- Sleep Foundation. Dry mouth at night: causes, prevention, and treatment. Medically reviewed by Abhinav Singh, MD. Updated 16 July 2026. https://www.sleepfoundation.org/physical-health/dry-mouth-at-night-while-sleeping
- healthdirect Australia. Dry mouth syndrome. Last reviewed October 2023. https://www.healthdirect.gov.au/dry-mouth-syndrome
- Sleep Foundation. Sleeping with your mouth open. Written by Elizabeth Rausch-Phung, MD; medically reviewed by Abhinav Singh, MD. Updated 14 October 2025. https://www.sleepfoundation.org/snoring/sleeping-with-mouth-open
- Choi JE, Waddell JN, Lyons KM, Kieser JA. Intraoral pH and temperature during sleep with and without mouth breathing. Journal of Oral Rehabilitation. 2016;43(5):356-363. https://doi.org/10.1111/joor.12372
- Sleep Foundation. How to stop snoring: expert tips for quieter sleep. Medically reviewed by Abhinav Singh, MD. Updated 11 November 2026. https://www.sleepfoundation.org/snoring/how-to-stop-snoring
- Sleep Foundation. Mouth taping for sleep: does it work? Medically reviewed by Anis Rehman, MD. Updated 23 March 2026. https://www.sleepfoundation.org/snoring/mouth-taping-for-sleep
- Rhee J, Iansavitchene A, Mannala S, Graham ME, Rotenberg B. 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;20(5):e0323643. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0323643
- Bowring D. What is mouth taping and will it fix your bad sleep? ABC News, 21 September 2022. https://www.abc.net.au/news/2022-09-21/mouth-taping-sleep-is-it-safe/101430200