Why Should You Drink Water in the Morning Before Brushing?

Introduction

It is often said that you should drink at least 7-8 glasses of water every day¹. Your body needs water to carry out all of its essential functions, like maintaining a normal temperature, keeping the joints flexible, and helping remove the waste². While it is clear that drinking water at regular intervals is important, some people remain uncertain and often ask, “Should I drink water before or after brushing my teeth?” 

Drinking Water First Thing in the Morning

You can safely drink water right after waking up, even before you brush your teeth. While it doesn’t replace oral hygiene, it can support your overall health in the following ways: 

• Rehydration: Your body uses up fluids during sleep, and you don’t usually drink water overnight. Having a glass of water in the morning helps replenish lost fluids and rehydrate your system². 
• Mouth freshness: Although drinking water does not remove plaque or bacteria (brushing your teeth with fluoride toothpaste is essential for that)³, it may help clean the mouth and wash away some of the dryness, making brushing feel more effective. 
• Hydration and body functions: Staying well-hydrated supports circulation, digestion, and energy levels. In people who are dehydrated, water intake may also help stabilise blood pressure and blood sugar levels⁴. 
• Digestive comfort: Drinking water on an empty stomach may help dilute stomach acid and reduce feelings of indigestion in some individuals. 
• Immunity: When you drink water regularly before brushing, you may notice your immunity becoming more robust. There may be fewer incidents of illnesses such as common cough and cold, flu or hay fever. 
• Skin health: Drinking an adequate amount of water is important for maintaining healthy-looking skin⁴. 

Let me tell you about an interesting observation. In a study¹⁰, it was seen that drinking water before a meal might help overweight and obese older adults eat less. Adults were given either a glass of water or no water before breakfast. The ones who drank water ate about 13% less food. This suggests that drinking water before snacks or meals may be a simple but effective way for older adults to control their weight.

Dr. Siddharth Gupta, B.A.M.S, M.D (Ayu)

What Causes Bad Morning Breath?

• A common cause of bad breath is dry mouth, which often occurs during sleep when saliva production decreases. Saliva helps protect the mouth as its contents control bacteria levels in the mouth and by washing away food particles stuck between the teeth. With less saliva at night, bacteria can grow more easily, leading to bad morning breath. As bacteria feed on leftover food between the teeth, brushing and flossing before bed may help reduce this problem^5,6. 
• Drinking water in the morning may help wash away these bacteria³, ease the dryness, and dilute some of the compounds that cause odour. In addition to brushing and flossing, rinsing your mouth with water after meals can help reduce leftover food particles on your teeth. 

From what I have seen, dehydration may make you feel tired and even nauseous. Sometimes, when you wake up in the morning not feeling great, it’s because your body didn’t get enough water the previous day. Water is important because it improves the blood and oxygen flow, which might make you feel more awake and energised. To start your day off right, try drinking a large glass of water as soon as you wake up¹¹!

Dr. Smita Barode, B.A.M.S, M.S.

What About Drinking Water After Brushing?

• Drinking water or rinsing with a lot of water after brushing your teeth reduces the efficacy of your toothpaste as the residual fluoride may get washed away⁷. But drinking a small amount of water after brushing (especially if done gently or after a few minutes) may not completely remove the benefits. 
• Wait up to 30 minutes before you drink or rinse your mouth after brushing⁷. 

From my perspective, it is important to stay hydrated to avoid headaches caused by water deprivation and dehydration. Therefore, drinking water as soon as you wake up in the morning might help with dehydration-related headaches throughout the day¹².

Dr. Rajeev Singh, BAMS

Conclusion

Drinking water before brushing may be a helpful habit, as it can ease dryness in the mouth, wash away some of the compounds that cause odour, and start the process of rehydrating the body after a night’s sleep. While it should not be seen as a cure for health problems, drinking water before brushing keeps the body well hydrated, helping it function smoothly and complementing daily oral hygiene. 

Also Read: Benefits of Eating Dinner Early for Better Health

Frequently Asked Questions (FAQs)

References

1. Valtin H. “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 x 8”? Am J Physiol Regul Integr Comp Physiol. 2002 Nov;283(5):R993-1004. Available from: https://pubmed.ncbi.nlm.nih.gov/12376390/  
2.  Lorenzo I, Serra-Prat M, Yébenes JC. The Role of Water Homeostasis in Muscle Function and Frailty: A Review. Nutrients. 2019 Aug 9;11(8):1857. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6723611/  
3. Nassar Y, Brizuela M. The Role of Fluoride on Caries Prevention. [Updated 2023 Mar 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK587342/  
4. Popkin BM, D’Anci KE, Rosenberg IH. Water, hydration, and health. Nutr Rev. 2010 Aug;68(8):439-58. doi: 10.1111/j.1753-4887.2010.00304.x.Availablr from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2908954  
5.  Khounganian RM, Alasmari ON, Aldosari MM, Alghanemi NM. Causes and Management of Halitosis: A Narrative Review. Cureus. 2023 Aug 19;15(8):e43742. doi: 10.7759/cureus.43742. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC10506127/  
6. Bollen CM, Beikler T. Halitosis: the multidisciplinary approach. Int J Oral Sci. 2012 Jun;4(2):55-63. doi: 10.1038/ijos.2012.39.Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC3412664/  
7. Parakaw T, Srihirun S, Dararat P, Ruangsawasdi N. Kinetics of fluoride after brushing with the no-rinse method. BMC Oral Health. 2024 Sep 8;24(1):1050. doi: 10.1186/s12903-024-04807-4. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC11382452/ 
8. Meinders AJ, Meinders AE. Hoeveel water moeten we eigenlijk drinken? [How much water do we really need to drink?]. Ned Tijdschr Geneeskd. 2010;154:A1757. Available from: https://www.ntvg.nl/artikelen/hoeveel-water-moeten-we-eigenlijk-drinken 
9. Popkin BM, D’Anci KE, Rosenberg IH. Water, hydration, and health. Nutr Rev. 2010 Aug;68(8):439-58. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2908954/  
10. Davy BM, Dennis EA, Dengo AL, Wilson KL, Davy KP. Water consumption reduces energy intake at a breakfast meal in obese older adults. J Am Diet Assoc. 2008 Jul;108(7):1236–9. doi: 10.1016/j.jada.2008.04.013. Available from: https://pubmed.ncbi.nlm.nih.gov/18589036/
11. Cleveland Clinic. Are there any health benefits to drinking a gallon of water a day? [Internet]. Cleveland (OH): Cleveland Clinic; [cited 2025 Sep 12]. Available from: https://health.clevelandclinic.org/are-there-any-health-benefits-to-drinking-a-gallon-of-water-a-day
12. Popkin BM, D’Anci KE, Rosenberg IH. Water, hydration, and health. Nutr Rev. 2010 Aug;68(8):439-58. doi: 10.1111/j.1753-4887.2010.00304.x. PMID: 20646222; PMCID: PMC2908954. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2908954/

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