How to Kill Keto Breath

Keto Breath

Get that keto breath under control with these tips!

On low carbohydrate diets, it is possible to experience a phenomenon known as “keto breath”. Keto breath specifically refers to an off-putting, fruity smell, and it’s typically caused by one or two aspects of a low carbohydrate diet. Included in this article are a breakdown of what leads to keto breath and an attack plan for how to deal with it.

Setting the Scene:

Picture it. You’re out on a date with your lovely new Tinder match. She’s an easy three points above her pictures. The whole night is going well. You even stay on your ketogenic diet by going with the pro move; a steak smothered in butter and accompanied by the most amazing asparagus you’ve ever had. You then leave the restaurant. When you go in for a kiss, the girl’s face cringes like its melting. She might even push you away.The culprit? Your breath. Keto breath.

Why does it happen? Ketones smell weird!

When the body undergoes ketogenesis, it is actively producing ketone bodies for energy usage. Ketosis occurs when the body is an extremely fasted state or in a prolonged carbohydrate fast, and becomes “fat adapted”. This means the metabolic system has switched to burning fats in order to create alternative energy sources known as ketone bodies.

For most normal Western dieters, dietary glucose from carbohydrate sources are used to fuel the body. But when dietary glucose is starved (which includes not eating too much protein either), the body can create ketone bodies from body fat or dietary fat to keep everything running smoothly. The body tends to rely on three ketone bodies: acetone, beta hydroxybutyrate, and acetoacetate.[1]


This little bugger is a big part of the problem. Good news: It typically goes away!

While these ketone bodies are incredible for fueling the body, they come with a dark side effect — a fruity side effect. Ketone bodies have a unique, distinct sweet smell, and it’s one we’re just not used to! Your first thought might be…wow – I get to smell like I am chewing juicy fruit ALL of the time? What an advantage! However, you might recognize “acetone” from elsewhere[2]…We’ll give you a hint, it does some damage to the following…

Nail Polish Acetone

You guessed it! Keto breath often has the same stuff as nail polish remover!

That is correct! If you wind up producing a bit too much acetone, your breath will suddenly smell like none other than nail polish remover. Not exactly attractive!

Why does it happen? The protein hypothesis.

As you already know from our massive ketosis bible (if you don’t, go there now!) too much protein is a death wish for ketogenic dieters. Excessive protein can “spill over” into gluconeogenesis to produce glucose, effectively ending ketosis, as your body needs to deal with that blood sugar before worrying about ketones again.

First, protein itself can also lead to some nasty breath. Protein is processed through the urea cycle. When protein is broken down in the digestive tract, ammonia is produced as a by product. The ammonia, in turn, can also make either your urine or breath smell like kitty litter.[2] So low-carb, high-protein dieters (such as Atkins dieters) may have this to deal with, while keto dieters (high-fat, low-carb, moderate protein) will have the ketone breath to deal with!

On top of it all, bad breath (or halitosis to be exact) is typically blamed on bacteria present in the body. When bacteria breaks down food, specifically protein, volatile sulphur compounds, or VSCs, are produced.[3]

How do we fight it?

Based on the last two explanations, it may seem that keto breath is unavoidable. By being in ketosis, the body will produce more ketone bodies. These ketone bodies will continue to contribute to the breath situation. To maintain body composition during ketosis, we must eat protein, yet when that protein is broken down, the situation may get even worse.

However, there are several ways to address this common problem:

  1. The Nuclear Option: Consider Dropping Ketosis

    This is, of course, the easy way out. By reintroducing dietary carbohydrates, the body will cease production of the smelly ketone bodies. However, this is an extreme solution. Only consider this if the other options do not produce adequate results and you simply can’t handle it.

  2. Drop some Bacteria… with a tongue scraper!

    Your bad breath is more than likely caused by your diet, not your oral hygiene. Or so we hope. However, stepping up your oral hygiene game can work wonders for killing off some oral bacteria that are contributing to the problem.

    Keto Breath Tongue Scraper

    Bend this and use it to literally pull and scrape the odor-causing/retaining bacteria from your mouth!

    A commonly forgotten aspect of oral hygiene is efficient tongue scrubbing. By really getting at the tongue with a tongue scraper, you should notice some immediate effects on you breath.

    There are also many anti-bacterial mouth washes available. By slaughtering the bacteria that call your mouth home, the amount of VSCs being produced should fall dramatically. This, in turn, will improve your breath.

    However, bacteria is good for the digestion process, and nuking it all with alcoholic mouthwash all day is probably a net negative for overall health. We just prefer to remove some of it from the tongue, hence the tongue scraper, and using mouthwash only once a week or so as a ‘refresh’.

  3. Carb Free Gum/Breath Capsules

    Keto Supplements

    Keto Supplements like these are talk of the town – but will they really help keto dieters, and if so, how and when?

    This is another preferable option. Thankfully, in the glorious 2010s, carb free products are everywhere. By keeping wintergreen gum in your pocket at all times, you will easily be able to mask keto breath when it pops its ugly head around your social life. Be careful with the sugar alcohols present in some products (they’ll still have a minor blood sugar impact and can cause bloating / stomach upset) and try not to chew too many pieces in a single day.

    Breath capsules may be a better option. Typically composed of some sort of oil along with a pleasant smelling odorant, breath capsules by nature have a lower chance of impacting ketosis. They are definitely harder to find, however.

  4. Lower Protein

    By far a harrowing option for the weight-room denizens of our audience. By lowering your overall protein intake, you reduce the chance of ammonia contributing to your poor breath. Lower protein by a slight amount until you notice a perceivable difference.

    Protein intake can be tough with a keto diet – eat too much and you lose ketosis, but eat too little and you can lose muscle tissue. You need to monitor and see what’s best for you, so we don’t want you to go too low of protein!

  5. Likely the best option: time.

    By far the easiest solution. Keto breath seems to be a time-sensitive issue, just like the “keto rash” (subject for another blog post). It comes up, similar to the mental fog, in the early days and weeks of ketogenic adaptation.

    It has been reported anecdotally that keto breath solves itself over time, and this is likely the result of lowered acetone production over time. If the other interventions fail you, perhaps you just have to wait it out.

You can beat Keto Breath

So long story short? Grab yourself a tongue scraper, learn how to use it, monitor protein intake, and hang in there!

About the Author: Mike Roberto

Mike Roberto

Mike Roberto is a research scientist and water sports athlete who founded PricePlow. He is an n=1 diet experimenter with extensive experience in supplementation and dietary modification, whose personal expertise stems from several experiments done on himself while sharing lab tests.

Mike's goal is to bridge the gap between nutritional research scientists and non-academics who seek to better their health in a system that has catastrophically failed the public.

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  1. Paoli A. Ketogenic Diet for Obesity: Friend or Foe? International Journal of Environmental Research and Public Health. 2014;11(2):2092-2107;
  2. Barbara E. Goodman.Insights into digestion and absorption of major nutrients in humans. Advances in Physiology Education Jun 2010, 34 (2) 44-53;
  3. Aylıkcı BU, Çolak H. Halitosis: From diagnosis to management. Journal of Natural Science, Biology, and Medicine. 2013;4(1):14-23;;year=2013;volume=4;issue=1;spage=14;epage=23;aulast=Aylikci
  4. Ketosis Breath: Causes & Solutions for Bad Breath. (n.d.).
  5. Laura Dolson Could Your Low-Carb Diet Be Giving You Bad Breath;

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