Fasting causes bad breath, and as a muslim I fast these days.

It is permissible to brush your teeth whilst fasting but it does not help. I think the bad smell has nothing to do with mouth and is coming from stomach or something.

And chewing gum is not permissible during Ramadan and would count as breaking your fast. The reason for this is because of the sugar and other ingredients that the chewing gum contains, as you would be swallowing it.

How can I get rid of the bad smell without breaking my fast?

  • How do you brush? Should be better than gum anyway Apr 20, 2021 at 12:36

4 Answers 4


Before you begin your fast and afterwards in the evening be sure you drink enough water to hydrate yourself sufficiently. Reduced saliva and a dry mouth make your breath odour stronger.

In addition, practice regular oral hygiene which includes brushing your teeth, flossing between your teeth to remove plaque which will harden into tartar; and, scraping (or brushing) the back of your tongue will help.

To check how effective you are, scrape the back of your tongue with a spoon and let the 'stuff' dry a bit. That is what your breath smells like.

Bad "mask breath" is a good indicator of the odour of your breath.

Good luck.

  • A quicker and easier way to check how your breath smells is to lick the back of your hand and sniff it.
    – Tanath
    May 1, 2021 at 15:48

The thing that serves as the major reservoir for bad breath (or the bacteria that cause it) is the tongue.

Brush your tongue, and you should have better breath. This doesn’t resolve all sources of bad breath, of course, but it does resolve one large but easily-tackled source.

  • 1
    A tongue scraper has helped me.
    – jsf80238
    Apr 21, 2021 at 23:13

You can use non-alcoholic mouthwash to help your bad breath. You do not want mouthwash with alcohol in it because it will kill all the germs in your mouth and you don't want that. Your mouth has good and bad germs and you want to keep the good germs. Non-alcoholic mouthwash kills mostly the bad germs in your mouth. A water pick flosser is also another good way to help get rid of bad breath. The water pick will help you get the phlegm off your tonsils. Phlegm could be the cause of your bad breath.


What you are describing may be "keto breath". Low carbohydrate diets (including fasting) can switch your metabolism from one that digests sugars to one that digests fats. (That is a vastly oversimplified explanation but there is a vast amount now written about "ketosis" and "ketogenic diets" that you can read for more details.)

First, to determine whether that is what is happening, you should get a test. You can do a somewhat accurate test at home with strips that test your urine. There are numerous brands available through online retailers. You should only purchase the amount that you think you'll need in the short term because the strips degrade on exposure to air. For a more accurate test, you can get a blood test or a breath test from a medical professional.

Second, if the issue is ketosis and keto breath, there is little you can do about it. You should try increasing your intake of water, which may help to divert the ketones in your bloodstream to your urine instead of your breath, and may also help to keep your mouth hydrated which will reduce the activity of bacteria that may compound the problem. You could increase the amount of carbohydrates in your diet, but that is probably not the solution you are looking for (unless there is a medical issue that precludes fasting, which is maybe something you should discuss with a medical professional). You can try to mask the odour with low carbohydrate candies, chewing gum, and mouthwash.

If you look up "keto breath" online you may find other advice, but I haven't found much other than the above, and "wait for it to reduce on its own".

  • Fasting, as OP does, does not allow for drinking either, not even water, so your solution is not likely to work.
    – Willeke
    May 23, 2021 at 21:26
  • And ketosis is unlike to happen with intermittent fasting (what the religious practice would be called if it was done as a health thing) unless purposely combined with a ketogenic diet.
    – Stephie
    May 24, 2021 at 7:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.