If you’re in ketosis, you may notice your breath tastes metallic or has a chemical smell. Drinking plenty of water and lowering your protein intake may help reduce the taste and smell.

Changing your diet and increasing physical activity can help you reach your weight loss goals. But changing your diet doesn’t only involve a reduction of calories. It also involves modifying the types of foods you eat, which may cause certain side effects besides weight loss.

The ketogenic diet (or keto diet) is a high-fat, moderate-protein, low-carb diet designed to help you achieve ketosis. This is a natural metabolic state that occurs when you don’t receive enough carbs for energy and your body starts burning fat for fuel.

While the ketogenic diet and other low-carb diets can help you lose weight faster, “keto breath” is an unwanted side effect of ketosis. Here’s what you need to know about keto breath, including symptoms and how to get rid of it.

Keto breath produces a distinct taste or odor in the mouth that’s different from ordinary halitosis or bad breath. Some people describe keto breath as having a metallic taste. In addition to a funny taste in the mouth, keto breath can be fruity-smelling or have a strong odor that’s similar to nail polish remover.

To understand the cause of keto breath, it’s important to understand how metabolism works. Your body gets energy from a variety of food sources, including carbohydrates, fat, and protein. Typically, your body will break down carbohydrates or glucose for energy first, and then fat.

Since the ketogenic diet and other low-carb diets purposely restrict your intake of carbohydrates, your body is forced to use its fat stores for energy once you’ve depleted your glucose stores. Ketosis occurs when your body breaks down fat for energy.

Fatty acids are then converted into ketones, which are natural chemicals your body produces when you burn fat for energy. These include beta hydroxybutyrate, acetoacetate, and acetone.

Ketones are usually harmless and released from the body through exhalation and urination. Since acetone is an ingredient in some nail polishes, your breath smelling like nail polish remover in particular can indicate a state of ketosis. On the one hand, this indication that you’ve entered ketosis may be reassuring. On the other hand, it’s an unfortunate indicator.

Some people on the ketogenic diet never experience keto breath. For those who do, the odor can be troublesome. But keto breath is temporary.

You may notice a change in your breath within days or a week of starting a low-carb diet. However, the odor will subside as your body adjusts to a lower carb intake. This might take a couple of weeks, and there are a few things you can do to freshen your breath during this period of time.

Here are a few simple tips to reduce bad breath while your body adjusts to a low-carb diet.

1. Increase your water intake

Along with exhalation, your body flushes acetone and ketones from your system through urination. Stay hydrated and sip on water throughout the day to increase urination. This helps flush ketones from your body and improves your breath. Drinking more water may also help with your weight loss goals.

2. Eat less protein

While protein is important on a low-carb diet, eating too much protein can worsen bad breath. As your body breaks down protein, it produces ammonia. This is another byproduct of metabolism that’s eliminated through urination and exhalation. Ammonia can create a strong odor on the breath, too.

Decreasing your protein and increasing your consumption of healthy fats (avocados, nuts, olive oil) may improve your breath without forcing you to go off the diet.

3. Practice good oral hygiene

Brushing your teeth twice a day and daily flossing may not completely eliminate keto breath, but these practices can reduce the odor coming from your mouth.

Bacteria can accumulate in your mouth and in between your teeth when you don’t brush or floss regularly. Since bacteria also triggers bad breath, poor dental hygiene can worsen keto breath.

4. Mask odor with mints and gum

You may want to suck on mints and chew gum until your body adjusts to a low-carb diet. Make sure you choose sugar-free mints and gum.

Be aware that some chewing gums and mints contain a small amount of carbohydrates. If you chew or suck on several pieces throughout the day, this could increase your daily intake of carbs and kick you out of ketosis.

5. Bump up your carb intake

Slightly increasing your carbohydrate intake can also eliminate keto breath. If you want to remain in a state of ketosis, only increase your daily amount of carbohydrates by a small amount.

Let’s say you’re eating 15 grams (g) of carbohydrates per day. Try increasing your intake to 20 g per day to see if your bad breath improves. Then, use a ketone breath analyzer to measure your ketone level. Monitoring your ketone level is key to knowing whether you’re still in ketosis after increasing your carbs.

6. Be patient

Sometimes, you can’t get rid of keto breath. So, if you’re committed to a low-carb diet to lose weight, be patient and allow your body to adjust to its new fuel source. Your bad breath will improve after a couple of weeks.

Keto breath is a side effect of ketosis and a low-carb diet, and there doesn’t appear to be a way to prevent the odor. What you can do, however, is use a ketone breath analyzer to determine the most carbs you can eat without being kicked out of ketosis. If you can add more carbs to your diet and eat less protein, this might be enough to keep your breath fresh.

If you notice keto breath and you’re not intentionally on the ketogenic diet or a low-carb diet, eating more carbs can quickly kick you out of ketosis and eliminate bad breath. For example, if you’re currently consuming 50 g of carbohydrates per day, up your intake to 100 g per day. You can increase your amount of physical activity to compensate for the added carbohydrates.

A low-carb diet can help you lose weight faster, but keto breath is one side effect that you can’t always ignore. If you’re determined to turn your body into a fat-burning machine, don’t give up on the diet. Between mints, gum, and drinking more water, you might be able to mask the odor until keto breath subsides.