Ketosis is a phase full of symptoms both good and bad and bad breath happens to be just one of them. As normal as it is to have bad breath, there are ways to eliminate that and this guide is here to help so you can embrace the full awesomeness of ketosis!

The ketogenic diet is a diet loved by many because it is something that really delivers noticeable results. So people who are successful in losing weight are most likely going to spread the word to as many friends as possible… What can possibly go wrong here?

Well, some might be put off with the all the habit changes required while others who decide to take the plunge might find themselves in a bind with some of the negative symptoms you can expect throughout the journey. The symptoms are normally associated with most low-carb diets.

This includes insomnia, diarrhea and short-term fatigue. With some determination, it is possible to overcome those. However, there is another symptom that could serve as an annoying thorn even as you approach ketosis and that’s bad breath.

So if you ever find yourself with unusually bad breath while you are working so hard in changing your eating habits, don’t panic! It’s completely normal! What you need to focus on right now is getting rid of that. The key is knowing exactly what causes bad breath so you will fully understand why the solutions found in this guide are guaranteed to help to some degree.

Is Bad Breath Really Normal?

Try to join the various online groups that promote ketogenic diets and other forms of low-carb diets including Atkins, South Beach and even Paleo diets. Ask if bad breath is a common thing and you are sure to get some replies acknowledging it.

There was this one survey conducted by some scientists claiming that 40 percent of the people on these diets report bad breath. You will notice that not everyone experiences this problem just like how not everyone experiences keto flu although bad breath is a little bit more complicated since there are natural causes to bad breath in addition to ketogenic-specific ones.

What Causes Bad Breath?

Before you think about your new ketogenic habits, you should first acknowledge that bad breath in general can be caused by a number of things whether you are on a diet plan or not. It is important to know these things so you can cross those out and narrow it down to the ketosis-specific ones.

The Natural Causes

  • Not brushing and flossing your teeth – This is an obvious one! If you are not brushing your teeth three times a day, you better get to that habit pronto! Grab the highest-rated toothpaste product in your favorite online store or buy it local and build up the habit! Besides, frequent brushing is one of the most effective ways to get rid of those snacking temptations! Don’t forget to floss too! The last thing you need right now is tiny bacteria ruling inside your mouth causing all sorts of trouble from gum disease to tooth decay.
  • Consumption of certain foods – Bad breath doesn’t just come from your mouth and teeth. There are some cases where awful smelling gases can be produced within your stomach. It might happen when you experience constipation or it could happen if you eat certain foods such as a cabbage, garlic, onion or other spices. Understand that bad breath can be the result of chemical reactions occurring inside your body and that explains why all the brushing, flossing and washing in the world won’t alleviate the problem.
  • Smoking – Smoking is just not good for your health, plain and simple. But if that cliché line isn’t enough for you to drop that habit, always remember this one motivating fact – being on the ketogenic diet feels a lot like the phases you go through when you suddenly go cold turkey on smoking. So you might as well quit the habits while going through the inevitable keto flu and come out feeling amazing knowing that you ticked off one of the main causes of bad breath!
  • Xerostomia – Xerostomia is commonly associated with having a dry mouth. Dry mouth means lack of saliva production. Lack of saliva production means that your mouth isn’t getting the regular cleaning and lubrication it needs to flush down those food particles. Leaving those food particles in your mouth causes rotting which in turn produces bad breath.

The Ketogenic Causes

  • Acetones – This is where things get a little scientific but first understand that a lot of people refer to this as “Ketosis Breath” or “Keto-Breath” for short. It is because the ketogenic diet is derived from the term “ketone” and ketones happen to be molecules generated within the liver as you metabolize the fats you consume. There are also certain types of ketones that are excreted in the breath and urine. These ketones are called acetones and it is those molecules that have a fairly unpleasant smell.
  • Ammonia – A lot of people have different approaches to minimizing their carb intakes. Some go for a really strict diet following only the stuff mentioned in those ketogenic recipe books and other guides while others have a broader variety that involves lots of protein. There is nothing wrong with a little bit of extra protein in your diet but bad breath is a possible side effect to that path. Like fats, your body metabolizes proteins too resulting to the formation of ammonia. Too much protein means more ammonia build up and that’s where the awful smell of ammonia can get pretty noticeable. It is more apparent when you have more protein than you need because the excess protein gets converted to energy and that’s where ammonia is normally the byproduct. Some people refer to this as “Ammonia Breath”.

What is Keto Breath?

The most effective way to identify the cause of bad breath is to assume that both natural and ketogenic causes are in play here. Because the next section of this guide will focus on combating bad breath no matter what the cause is.

But if you really want to satisfy your curiosity and see if the ketogenic diet really is to blame, you can check if your breath contains excessive amounts of acetone. Acetone has that fruity, rotten apple-like smell but if you really want to make sure it is really present in your breath, you can try using a ketone breath analyzer.

The best part a ketone breath meter is that it doesn’t collect blood or urine samples and is surprisingly accurate.

How Long Does Ketosis Bad Breath Last?

The good news is, not forever. As your body adjusts to being in ketosis, any bad breath you have been suffering usually subsides.

Some people experience no keto breath, for others it could take 2 to 3 weeks for their bodies to fully adjust to the keto diet.

How to Fight the Bad Breath?

Here are a few practical approaches to fighting acetone breath or keto breath, as it is more commonly known. Remember to drink lots of water not only to stay well hydrated and decrease your appetite, but to help flush the ketones from your system.

Practical Early Approaches

  • Keep your Oral Hygiene in Top Condition – Once again, maintaining good oral hygiene is an absolute must! It may not solve the ketosis breath problem right away but it never hurts to try to keep your mouth clean around the clock. If you think manual brushing is too much for your hectic schedule, invest in an electronic toothbrush. Getting rid of the plaque is also very important so buy a mouthwash that fights plaque to keep your breath as fresh as possible. Also remember to clean your tongue regularly. Brushing it with baking soda or activated charcoal can be a good help.
  • Stock Up on Breath Masking Consumables – Toothpaste might be the most effective and accessible consumable against bad breath but having various other options at your disposal lets you attack the bad breath problem at multiple fronts. For instance, if you need an extra burst of minty freshness, carry a breath spray with you.
  • Mint-flavored chewing gum can also be a fantastic cover. Both of these options are particularly good for travelers who may not be able to brush right away. As practical as the advice may sound, don’t just blindly pick the most minty candy or breath spray. Treat these consumables as food and like any food, you have to make sure they adhere to the ketogenic diet. If the spray or gum is high on carbs, you could ruin your ketosis momentum so check the ingredients first. Even sugar-free candies and gum could have carbs
  • Drink Plenty of Fluids – It doesn’t matter if you believe in the so-called “eight glasses of water per day” myth; what does matter is the fact that drinking several glasses of water flushes out those toxins in your mouth and aids in salivary production. Do not rely on ketosis alone to get rid of those toxins. Remember, keeping yourself hydrated makes you sweat and sweating means excreting those toxins through your own body’s pores. As for the exact number of glasses to drink, that really depends on how much you weigh. For instance, if you weigh 160 pounds, then 160 ounces of water should suffice. It is also a good practice to drink at least 16 ounces of water shortly after you wake up as that is the phase where you are most dehydrated. Mix up the hydration with green juice, bone broth, herbal tea and fermented drinks for even better results.
  • Go with the Flow – Just like the keto flu, bad breath is a temporary phase where your body is just getting rid of the excess ketones. Depending on how often you use the above tips, the keto breath may come in and out for the next couple of weeks. If you do not have any lovely dates lined up for the next few weeks, perhaps you can ride through the unpleasant experience and wait for your body to adjust to your protein intake. With some patience, the bad breath just might fade away. If not, read on for some advanced tips in overcoming the ketosis bad breath predicament.

Advanced Approaches

  • Take the Natural Detour – If you are struggling to find a good low-carb breath spray, consider taking a more natural approach. There are certain types of herbs such as mint, parsley, thyme, cinnamon, fennel seeds and rosemary that are very effective in curing bad breath. It’s as simple as grabbing a couple of sprigs and chew away. Let us not forget too what other benefits fresh herbs bring in addition to promoting fresh breath. They contain key ingredients for digestive health and they increase digestive juice and acetylcholine production which is good for the brain. And all those benefits come without negatively affecting your ketogenic streak! If chewing herbs weirds you out or you are not so good in identifying herbs in general, try taking mint capsules instead. Some people have discovered breath capsules made from parsley oil to be pretty effective. Taking them in the morning is recommended as you will experience the freshness later within the day after taking. If you only experience bad breath right after you wake up (morning breath), try a natural mouthwash.
  • Resort to Essential Oils – Don’t forget too that essential oils are part of the natural category. Toothpastes that contain tea tree oil are pretty effective in fighting bad breath. Can’t find those types of toothpaste? Take your favorite toothpaste and add pure tea tree oil instead! If you believe that part of the problem is bacterial and plaque build-up, try this essential oil trick. Take a teaspoon of oil such as coconut oil and swish between your teeth after melting the oil in your mouth for a few minutes and spit it out. Adding some peppermint oil could make it even more effective as it helps control bacteria and adds a very pleasant aroma to the mix. Avoid swallowing it as you don’t want that harmful bacteria in your system. This trick is known as “oil pulling”.
  • Keep your Mouth Moisturized – Not all sprays are meant for masking bad breath. There is a special category of sprays called moisturizing mouth sprays that tackle the problem at a different angle. Moisturizing mouth sprays can be a good solution for people with a dry mouth. Remember how xerostomia was mentioned earlier as a natural cause to bad breath? The moisturizing mouth spray could be the solution you need. Just wait a few hours to a full day after a couple of sprays to your mouth.
  • Stimulate Salivation – Did you know that your own saliva helps control the growth of unwanted bacteria? That’s because saliva is an effective pH regulator. If you haven’t been talking so much lately, try to let the saliva pool inside your mouth for a few moments for better oral hygiene.
  • Try Mouth Taping – Don’t let the phrase “mouth taping” intimidate you. It is actually a technique that trains you to breathe through your nostrils instead of your mouth. This is not only important for having better sleep but it also promotes healthy teeth, gums and mouth and can serve as a more natural means of preventing dry mouth. All you need to do is take a piece of hypoallergenic tape and cover your mouth before you go to sleep.
  • Reduce Protein Intake – Ammonia can be a big contributor of bad breath and can even be worse when it is mixed with acetones. To begin with, you shouldn’t be consuming excessive amounts of protein in your ketogenic diet. Try to reduce that so your gut won’t struggle in breaking the large amounts of protein down. Limiting your protein to around 10 to 25 percent of calories on your ketogenic diet is recommended to reduce ammonia.
  • Deal with the Dairy – Dairy is a pretty complicated subject in the world of the ketogenic diet. Generally speaking, you want to avoid any low-fat products including milk and opt for full-fat versions of yogurt, butter and other creams. But one of the consequences of eating a lot of dairy is the film layer that can develop on your tongue. Also known as “white tongue”, this layer consists of food particles, bacteria and other debris on the tongue that secretes toxins and other foul smelling substances. Extra tongue brushing is your best bet if you had lots of dairy recently.
  • Balance the Bacteria – Just because dairy is a cause of bad breath doesn’t mean that you should eliminate it from your ketogenic diet. Probiotics and fermented foods are important too and are vital in keeping your immune system healthy with good bacteria. There are parasites and pathogens that can build up in the digestive tract which can affect the digestion of foods and produce unwanted gases which contribute to bad breath. A healthy bacterial community prevents this from happening.
  • Give Your Digestive System Some Relief – If you think those bad gases are coming from your stomach, simply avoid eating cruciferous veggies and other sulfurous foods. Limit the amount of garlic and onions to give your digestive system some relief. If you had a lot of these foods in the past couple of days, try to get into juicing. Keeping the ingredients as green as possible with low sugar content is recommended as the chlorophyll in these veggies promote better digestion.
  • Come Out of the Ketosis Phase – If the keto breath problem persists and you can no longer go with the flow, hitting the emergency breaks could be your last remaining option and that may involve coming out of ketosis. Making that decision is never easy but timing the break could soften the blow. For instance, you can plan to come out during a holiday or vacation so your bad breath doesn’t ruin that experience. Once you have settled with the idea of a keto break, slowly increase your carb intake. A slow gradual increase may even still leave you in ketosis. A range of 65 to 75 grams of carbs each day is pretty good estimate which should lead you to fresher breath for the next few days.

What Else Can I do?

If you tried everything mentioned here and still suffer from bad breath, the problem could lie elsewhere as there are plenty of other causes of bad breath. It could be a lung infection or sinusitis or something else entirely. Seeing a dentist or doctor could be your best bet especially if coming out of ketosis doesn’t work.

Ketogenic diet is not exactly a mainstream diet so your doctor or dentist may not even be familiar with it. What you want to do is rule out any other medical conditions so you can proceed back to ketosis once those problems are addressed and you can see if the bad breath persists.


Nobody likes having bad breath and it could be even worse if you are surrounded by friends and family members who might not have a single clue on what the ketogenic diet is.

But if you know you have that history of always having fresh breath and suddenly have awfully bad breath as you reach the ketosis phase, consider that a good sign knowing that the ketogenic diet is working and at the end of that long tunnel is a bright light taking the form of rapid weight loss and eventually no more bad breath when your body finally adjusts.

But even if you are not so confident that your bad breath will go away, you can at least rest easy knowing that there are multiple solutions to this problem. It is all about building new habits and if you have succeeded in developing new eating habits to comply with the ketogenic diet, forming new habits in keeping your breath fresh as possible shouldn’t be a huge issue.

Take it as a journey and a challenge and hopefully within a month you will emerge triumphant and you won’t have to be bothered with things like acetones and ammonia ever again. You will also realize just how awesome being in ketosis is and how it is a phase you do not want to get out of.