- Mouthwash is optional. It does not replace brushing twice a day and cleaning between your teeth.
- Fluoride mouthwash can help prevent decay. Antiseptic mouthwash can help with plaque and gum inflammation. Cosmetic mouthwash only freshens breath for a while.
- The NHS advises not using mouthwash straight after brushing: use it at a different time, such as after lunch.
- Children under 6 should not use mouthwash unless a dentist advises it.
- Chlorhexidine mouthwash is for short-term use and can stain teeth; the staining is not permanent.
Mouthwash (also called mouth rinse) is sold alongside toothpaste as though it were an essential step, but health bodies are more cautious. healthdirect Australia says most people do not need to use mouthwash, and suggests talking to your dental practitioner about the risks and benefits of using it regularly. The American Dental Association describes it as a possible helpful addition for some people, but not a replacement for daily brushing and flossing.
What types of mouthwash are there?
The American Dental Association divides mouthwashes into two broad groups.
Cosmetic mouthwashes may temporarily control bad breath and leave a pleasant taste, but they do not reduce your risk of tooth decay or gum disease.
Therapeutic mouthwashes contain an active ingredient aimed at a particular problem. The main ones are:
- Fluoride, which the American Dental Association calls a proven agent for helping to prevent decay.
- Antiseptics (substances that kill or slow the growth of bacteria), such as chlorhexidine, cetylpyridinium chloride and essential oils. The American Dental Association says these can help reduce plaque and gingivitis (inflamed gums, the early stage of gum disease) when combined with daily brushing and flossing.
- Peroxide, found in some whitening mouthwashes.
When can mouthwash help?
To help prevent tooth decay
The NHS says a mouthwash containing fluoride can help prevent tooth decay, and the Oral Health Foundation says it should be used as well as brushing, not instead of it. A Cochrane review, combining 35 trials in children and teenagers aged 6 to 14, found that supervised, regular use of fluoride mouthwash reduced decayed, missing and filled surfaces of adult teeth by 27% on average, and that this benefit is likely even for children who use fluoride toothpaste or live in areas with fluoridated water. The trials were mostly in schools, and the evidence was rated moderate quality.
A dentist may suggest fluoride mouthwash if you are at higher risk of decay. The American Dental Association notes that fluoride mouthwash may help people with a dry mouth, since a lack of saliva raises the risk of decay, and suggests an alcohol-free product because alcohol can be drying.
For plaque and gum problems
According to the American Dental Association, antiseptic mouthwashes can benefit people who cannot control plaque and gingivitis well enough through brushing and cleaning between their teeth alone, but they are not a substitute for that cleaning. The NHS says chlorhexidine mouthwash can help with gum disease, mouth infections and mouth ulcers.
For bad breath
For bad breath, the NHS says you could try an antibacterial mouthwash or toothpaste, alongside brushing, cleaning between your teeth and cleaning your tongue. The American Dental Association explains that cosmetic mouthwashes only mask bad breath, while antiseptic ones may control it for longer. If bad breath does not go away after a few weeks of looking after your mouth, the NHS advises seeing a dentist.
When should you use it?
Advice on timing differs between countries.
- The NHS advises not using mouthwash, even a fluoride one, straight after brushing, because it washes away the concentrated fluoride from your toothpaste left on your teeth. It suggests choosing a different time, such as after lunch. The Oral Health Foundation also says to use fluoride mouthwash at a different time from brushing.
- The American Dental Association says whether to rinse before or after brushing may be a matter of personal preference, but that manufacturers may recommend a particular order depending on the ingredients.
After a fluoride mouthwash, the NHS says not to eat or drink for 30 minutes. For chlorhexidine, the NHS says to wait at least 30 minutes before eating or drinking, and to use it at a different time from brushing because toothpaste can stop it working properly. If that is not possible, rinse your mouth thoroughly with water after brushing and wait at least 5 minutes before using it.
Whichever mouthwash you use, follow the instructions on the label, or from your dentist or pharmacist.
Chlorhexidine: what to know
Chlorhexidine is an antiseptic used for short-term treatment. In the UK, the NHS says many chlorhexidine products can be bought in pharmacies, and some in shops and supermarkets. In the US, the American Dental Association says chlorhexidine mouthwash is available only on prescription.
How to use it
The NHS gives the usual adult dose as 10 ml twice a day, rinsed around the mouth for about 1 minute and then spat out, not swallowed. It is usually used for up to 4 weeks, and for 4 weeks for gum disease. For mouth ulcers and oral thrush, the NHS says to carry on for 2 days after symptoms have gone. If your symptoms have not improved after a week, or get worse, stop using it and contact your dentist or doctor.
Staining and other side effects
Tooth staining is one of the best-known side effects. The NHS lists stained teeth and a change in tongue colour among the common side effects, and says neither is permanent: both go when you stop using chlorhexidine. It also says the treatments can stain your teeth if used for longer than the usual course. The American Dental Association notes that chlorhexidine and cetylpyridinium chloride may cause brown staining of teeth, tongue and fillings.
Other common side effects listed by the NHS include a dry mouth and a brief burning, tingling or strange taste, which usually improves as you keep using it. The NHS says a serious allergic reaction is extremely rare.
Mouthwash and children
Health bodies advise caution with young children, who are more likely to swallow mouthwash:
- The American Dental Association says children under 6 should not use mouthwash unless a dentist recommends it. Swallowing large amounts can cause nausea, vomiting and, with rinses that contain alcohol, intoxication.
- The American Dental Association and Cochrane both say fluoride mouthwash is not recommended under 6, because repeatedly swallowing it raises the risk of dental fluorosis (marks on the adult teeth caused by too much fluoride while they are forming).
- The NHS says chlorhexidine mouthwash can be used by adults and children aged 12 and over.
The American Dental Association also advises checking the label for age recommendations.
Does alcohol in mouthwash cause mouth cancer?
Some mouthwashes contain alcohol, and people sometimes worry about this. The American Dental Association reports that a systematic review and meta-analysis did not find an association between mouthwash use, or alcohol-containing mouthwash, and oral cancer. The American Dental Association does suggest an alcohol-free rinse for people with a dry mouth, because alcohol can be drying. The NHS notes that some chlorhexidine mouthwashes contain small amounts of alcohol, and suggests asking a pharmacist, doctor or dentist about alcohol-free options if you need to avoid it.
- You are thinking of using mouthwash every day and want to know whether you need it or which type suits you.
- You have bad breath that does not improve after a few weeks of brushing, cleaning between your teeth and cleaning your tongue.
- Your gums bleed, or are red, swollen or sore.
- You have used chlorhexidine for a week and your symptoms have not improved, or your mouth feels sore or irritated.
- After using chlorhexidine, your lips, mouth, throat or tongue suddenly swell, or you have trouble breathing or swallowing: call emergency services (999 in the UK). The NHS says these can be signs of a serious allergic reaction.
- You or your child have swallowed chlorhexidine mouthwash and feel unwell: get urgent medical advice (NHS 111 in the UK).
Frequently asked questions
Can mouthwash replace brushing or flossing?
No. The American Dental Association says mouthwash is not a replacement for daily brushing and flossing, and the Oral Health Foundation says fluoride mouthwash should be used as well as brushing, not instead of it.
Should I use mouthwash straight after brushing?
The NHS advises against it, because it rinses away the fluoride from your toothpaste. Use it at another time of day, such as after lunch. The American Dental Association treats the order as more a matter of preference and product instructions.
Will chlorhexidine stain my teeth permanently?
No. The NHS says staining is not permanent and goes when you stop using it. Keep brushing regularly, and use it only for as long as advised.
Can my child use mouthwash?
Not under 6 unless a dentist recommends it, according to the American Dental Association. The NHS says chlorhexidine mouthwash is for children aged 12 and over.
Sources
- How to keep your teeth clean, NHS, accessed September 2026
- About chlorhexidine, NHS, accessed September 2026
- Who can and cannot use chlorhexidine, NHS, accessed September 2026
- How and when to use chlorhexidine, NHS, accessed September 2026
- Side effects of chlorhexidine, NHS, accessed September 2026
- Bad breath, NHS, accessed September 2026
- Fluoride, Oral Health Foundation, accessed September 2026
- Dental care and teeth cleaning, healthdirect Australia, accessed September 2026
- Mouthwash, American Dental Association (MouthHealthy), accessed September 2026
- Mouthrinse (mouthwash), American Dental Association, accessed September 2026
- Fluoride: topical and systemic supplements, American Dental Association, accessed September 2026
- Fluoride mouthrinses for preventing dental caries in children and adolescents, Cochrane, accessed September 2026
This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.