You’ve started on the keto diet and notice something’s off

You can taste a metallic, unappetizing taste in your mouth that wasn’t there before. This unpleasant but totally temporary new taste is known as “keto breath.”

While the the keto diet has been proven to result in a variety of great health benefits through drastically reducing carb intake, don’t be too surprised if you start experiencing some pesky side effects—like keto breath—in the beginning.

It’s just your body adjusting to the changes that come from altering your diet so drastically.

In this article,

we’re going to review what keto breath is and how you can overcome it as quickly as possible!

What Causes Keto Breath

During the first week or two of the keto diet, your body is going to go through some adjustments as you lower your carb intake and rely more on healthy fats.

These changes can range from disrupted sleep to experiencing the “keto flu”, which can encompass everything from nausea to dizziness. The keto diet is based on changes your body makes when it stores the glucose from carbohydrates as an energy source.

After consuming a reduced amount of carbohydrates, your body will use up all of the stored glucose for energy.

When your body breaks down the fat for energy and changes it into ketones, the process is known as ketosis.

Once your body is in a state of ketosis, your body produces less hunger signaling hormones, which means less calories consumed per day because of greater satiety.

Ketones are natural chemicals your body produces during this process. Some of these ketones are acetone, beta hydroxybutyrate, and acetoacetate. Acetone is is thought to be the main culprit behind keto breath, and is a pretty reliable indicator that you’re in ketosis.

Acetone is known as a volatile, present chemical, so it is fairly easy and non-invasive to measure. These are often measured by ketone measurement devices or inexpensive “breathalyzers” sensitive to acetone.

Acetone is actually a main ingredient found in some nail polishes, so when your breath starts to smell or taste like nail polish remover, it could be an indicator that ketosis is occuring.

Though it’s a good thing when you’re entering ketosis—since it shows the keto diet is working—it’s not such a good thing to harbor a bad-tasting smell/taste in your mouth[1].

We get it. Bad breath can be a troublesome hygiene problem. Not only is it socially embarrassing, but it can even lead to complications with your interpersonal relationships. Bad breath can also lead to avoidance behaviors, depression, and anxiety.

One study examined the emotional effects of bad breath, citing that the National Dental Association reported that 50% of the adult population has suffered from an occasional malodor disorder, and 25% have been reported to have a chronic problem.

Obviously, external factors contribute to bad breath too, such as alcohol consumption, smoking, and poor oral hygiene. Internal factors ranged from liver diseases to gastrointestinal issues.

Another situational cause was dental anxiety, or fear of going to the dentist. This can lead to patients to avoid visits and treatments.

The biggest emotional after effect of bad breath was anxiety[2].

Ways to Counteract the Effects of Bad Breath

There are ways to beat this bad odor, so hang in there!

The following suggestions will not only improve your breath, but also your overall oral health and hygiene.

Drink more water.

Drinking water is helpful for a variety of dietary issues. But water will help you flush out acetone and ketones from your system. The more water you drink, the faster this flushing out process will occur.

Give more care to your oral hygiene.

Make sure you’re brushing and flossing! There also a variety of keto-friendly gums to cure bad breath, with PUR gum being one of the most popular.

PUR gum has no artificial flavoring like aspartame, no chemicals, and is also gluten free. Also, consider tongue scrapers and zinc toothpaste.

Ease up on the protein.

The keto diet only requires moderate protein consumption, not necessarily high consumption. The compounds and fats in the protein could be triggering odorous breath.

Slightly increase your carb intake.

Since keto breath is driven by ketosis, with the presence of the odorous acetone, see if a slight increase in carb intake can help alleviate the keto breath.

Ketone measurement tools will be useful ways to track the presence of ketones, not just for bad breath but also to see if you are on track with following the diet and assessing if you are at ketosis.

Precision Xtra is one of the most well-known and popular blood glucose and ketone monitoring systems on the market. This is advantageous to people who have diabetes. This system is a way to test your blood’s glucose and ketone levels on test strips.

Typically, after five seconds, the meter will show you the appropriate results. If your ketone count is high, it is an explanation for accompanying keto breath.


Though there is evidentiary support that keto breath means that ketosis is in effect, it is overall unpleasant to have bitter-tasting breath.

Just hang in there and know that this is only a temporary side effect as your body adjusts to the ketogenic lifestyle.

After all, the keto diet has been proven to improve health in a majority of ways, like helping people with significant weight loss.

In the meantime, start making some minor adjustments and pay more attention to your oral hygiene routine to kick that keto breath to the curb!


Keto Headache – Why You Have it and How to Prevent it

Keto Rash – Why You’re Itchy & How to Stop it

What is Ketoacidosis?

The Keto Flu: What is it and How to Fix It

8 Tips For Getting More Sleep & Beating Keto Insomnia

5 Reasons Why You’re Experiencing Sudden Weight Gain On Keto & How To Fix It!


[1] Musa-Veloso K, Likhodii SS, Cunnane SC. Breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals. Am J Clin Nutr. 2002 Jul;76(1):65-70.

[2] Settineri S, Mento C, Gugliotta SC, Saitta A, Terranova A, Trimarchi G, Mallamace D. Self-reported halitosis and emotional state: impact on oral conditions and treatments. Health Qual Life Outcomes. 2010 Mar 26;8:34. doi: 10.1186/1477-7525-8-34.



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