What Causes Keto Breath? [And How To Fix It]

Something I wondered when I first started a keto diet was why my breath had a new odor and even a certain taste to it. If I could notice a different smell on my own breath… I can only imagine what everyone else was smelling. 

What is keto breath?

Keto breath is often one of the unwanted side effects of a keto diet that results in an almost metallic taste and smell in the mouth, similar to that of nail polish. 

Keto breath pinterest cover

What causes keto breath?

In short, while on a ketogenic diet your primary fuel source switches from glucose (sugar) to ketones (fat). 

The liver makes three types of ketones:

  1. Acetone
  2. Acetoacetate
  3. Beta-Hydroxybutyrate (BHB)

One way in which we excrete acetone from the body is through the breath. Therefore, you’ll often have that acetone scent, much like nail polish, but  typically during the first few weeks of a ketogenic diet. 

It‘s not all doom and gloom though. First off, this probably means you are in a state of ketosis, and second, keto breath eventually resolves on its own within a couple weeks.

How long does keto breath last?

From my experience, keto breath will typically last a few weeks.

During the first weeks of a ketogenic diet, your body isn’t as efficient at using ketones just yet. Because of this inefficiency, the body tends to “waste” ketones in the sense it excretes them, through the breath and urine, without using them. 

If you’ve ever heard about “keto-adaptation” or becoming “fat-adapted,” this is a period of about 3-4 weeks when your body is becoming accustomed to using fat as its primary fuel. Certain enzymes and transporters within your body must be upregulated to use ketones more efficiently. 

It‘s usually after this period of keto-adaptation that keto breath goes away. Your body becomes more efficient at using ketones which means less waste through breath and urine.

Once you become keto-adapted, keto breath tends to go away. This is usually a period of about 3-4 weeks but can be shorter or longer depending on the individual.

What does keto breath taste like?

Not only is keto breath characterized by a particular smell, but you may notice a certain taste. Many people report an almost sweet metallic taste in their mouth when starting a ketogenic diet.

Similar to the fruity acetone smell, this too will go away once your body switches its source of energy from glucose to ketones leaving less to be excreted as waste.

So now you might wonder, is there a keto breath cure? Can I speed up the timetable?

Yes and no, let’s see what I mean.

How to get rid of keto breath

Since ketosis breath is often a result of being inefficient at using ketones, the only true way is to become keto adapted. Since time is the only surefire way of allowing one to become fat adapted, there may still be ways we can expedite this process.

Exogenous Ketones and MCT Oil

Exogenous ketones can be a great way to upregulate the transporters in our body. By artificially increasing our blood ketones, we may bypass the time it takes for our blood ketones to rise naturally and upregulate the transporters needed for ketones to be used versus wasted.

Most ketone supplements use beta-hydroxybutyrate (BHB) as the main ingredient since BHB is the most efficient ketone body relative to acetoacetate and acetone.

I recommend: Perfect Keto BHB

Another popular way if you don‘t want to go the BHB route is increasing your MCT Oil consumption. MCT Oil can moderately raise BHB levels, but only after your body converts it in the liver. 

MCT‘s are an indirect route versus exogenous ketones but accomplishes the same concept in the grand scheme of things. 

I recommend: Viva MCT Oil or Perfect Keto MCT Oil Powder

Exercise

Beyond reducing our carb intake and eating relatively high fat, we can speed up keto-adaptation by including exercise.

Going back to raising BHB within our body, some studies point out that exercise has the potential to increase BHB levels. 1 

Fasting

Keto and intermittent fasting go together like peanut butter and jelly. While we fast, our body increases fatty acid mobilization. 2 

As you can see, the above methods share one thing in common. All the methods aim to increase levels of blood ketones, BHB in particular.

How to cure keto breath in the meantime

Chew some sugar-free gum or keto friendly breath mints

Almost all sugar-free gum and mints should relatively be ok. I‘d probably avoid mints and gums sweetened with maltitol as it has been shown to have the same effect on blood sugar as regular table sugar.

And goes without saying, but I’ll say it anyway, don‘t go crazy chewing up packs of gum and eating boxes of mints every day.

Drink water… a lot of it! 

At the beginning of a ketogenic diet, many people find themselves slightly dehydrated. When we reduce our carbohydrate intake we also flush out a lot of water. 

A dry mouth combined with acetone will make for an even more pungent combination.

Increase your oral hygiene AKA, brush your teeth more frequently and/or use mouthwash.

Not only will good oral hygiene rule out the possibility of just having bad breath, but every little bit helps. 

You may also want to use this as a good time to start or increase your frequency of tongue scraping.

Lastly, simply wait… BE PATIENT

Sometimes it may be impossible to get rid of keto breath with any interventions and the only answer is to give it enough time. Besides, it‘s only a few weeks in the grand scheme of things.

Wrapping up keto breath

So if you find yourself wondering is keto breath temporary?

The answer is a resounding yes! Exercise patience, use the tips provided to help speed up keto-adaptation and be rest assured it will come and go before you know it.

What does your breath smell like when you're in ketosis?

When in ketosis, people often report an almost fruity, acetone like scent on their breath.

How do you get rid of ketone breath?

The only real way to get rid of ketone breath is to be patient and let time run its course. Ketone breath usually goes away once you become efficient at using ketones for energy.

What causes ketone breath?

Ketone breath is caused due to the inefficiency of ketone use at the beginning of a diet. One of the ketone bodies, acetone, is expelled via the breath.

Does keto diet make your breath stink?

Depending on your definition of “stink,” it does have a particular odor.

How do I stop keto breath?

There is no way to stop keto breath from happening, it will either happen or not.

Does keto breath ever go away?

Yes, keto breath will go away once you become keto-adapated, or efficient at using ketones for energy.

Is bad breath a sign of ketosis?

Bad breath in particular isn't a sign of ketosis. However, if it's a new scent that coincided with starting a ketogenic diet, then it may be.

How do you beat keto breath?

You beat keto breath by with patience. Keto breath will usually go away after 3 – 4 weeks on its own.

Does everyone get bad breath in ketosis?

Not everyone shares the same fate when it comes to keto breath. Some individuals never get the fruity smell or metallic taste in their mouth.