What Do Ketones Smell Like?


Ketones, a fat-metabolism leftover, give off an unmistakable odor. Folks on a low-carb, high-fat diet may experience this smell as their bodies enter ketosis. People say it smells like fruit or nail polish remover, thanks to acetone in breath and sweat. Brushing teeth and drinking lots of water can help reduce the smell. Although safe, it’s important to check ketone levels for people with diabetes; it could mean diabetic ketoacidosis.

What are Ketones?

Ketones are chemicals created by the liver when it breaks down fat for energy. They’re detected in blood and urine, showing a shift towards fat burning.

Ketones have a unique odor – described as fruity or sweet. It could remind you of acetone or nail polish remover. This smell may be noticed on breath or skin, particularly during ketosis.

Ketones have other roles too, such as controlling appetite and keeping your brain going. Plus, they can act as signaling molecules and have anti-inflammatory effects. However, too many ketones can cause DKA in people with uncontrolled diabetes.

Why do Ketones Smell?

In individuals with uncontrolled diabetes, the excess production of ketones leads to a distinctive smell called “ketosis breath.” This occurs as a result of the breakdown of fatty acids in the liver and subsequent release of ketones into the bloodstream, which are then expelled through the breath. Ketones emit an odor that is often described as sweet, fruity, or similar to acetone. The reason why ketones smell is due to the presence of organic compounds such as acetone and beta-hydroxybutyric acid.

Further, it is essential to understand that the production of ketones is a normal metabolic process that occurs in the body during fasting or vigorous exercise. However, when the blood glucose level is not regulated in individuals with diabetes, this process is disrupted, leading to an accumulation of ketones in the bloodstream. This buildup of ketones results in the characteristic odor that is easily detectable on the breath.

Historically, the smell of “acetone breath” has been utilized in medical settings to diagnose and monitor diabetic ketoacidosis by healthcare professionals. However, with advances in technology, such as the development of ketone meters, the detection of ketones in the blood and urine has become more accurate and practical. Despite this, understanding the reason behind the smell of ketones can still provide valuable insight into the metabolic processes occurring in the body.

Ketosis: when your breath smells like a chemistry lab, but at least you’re losing weight!


When the body lacks carbs as energy, it burns fat for fuel instead. This is called Ketogenic diet. The metabolism of fats produces molecules called ketones. One of the by-products of ketone metabolism is acetone, which leaves through exhalation and sweat. This results in a fruity smell called ‘keto breath’. Keto breath increases when the body is on a Ketogenic diet or fasting. But, it usually goes away when the body adapts to burning fat over carbs.

Diabetic Ketoacidosis

Diabetic Acidosis occurs when cells don’t get enough glucose to produce energy. So, they use fat instead, causing a buildup of ketones in the blood. This lowers blood pH levels and can be life-threatening.

Fruity breath is a sign of ketone production. Acetone is what causes it. People with poorly managed diabetes usually have a stronger smell.

If you experience symptoms of Diabetic Ketoacidosis, you must seek help immediately. These include:

  • Frequent urination and thirst.
  • Unexplainable fatigue and rapid breathing.
  • Stomach pain, nausea, and vomiting.
  • Fruity breath or extreme dry mouth.

Side Effects of High Protein or Low Carb Diet

High-protein or low-carb diets can bring some consequences. Excess ketones, a by-product of these diets, cause a smell called “ketosis breath.

  • 1. Eating too much protein may cause digestive issues, fatigue and bad breath.
  • 2. Cutting carbs can lead to headaches, constipation and low energy levels.
  • 3. High-protein diets can put strain on kidneys, which may be fatal for people with impaired functioning.

It’s important to choose foods that provide all-round nutrition. Also, drink plenty of fluids to avoid dehydration.

What do Ketones Smell Like?

Ketones, organic compounds with a carbonyl group, have a distinct odor that can be described as fruity or sometimes sweet. Their smell is similar to that of nail polish remover or acetone. It is crucial to note that the amount of ketones in the body can increase in conditions such as diabetes, fasting, or a low-carb diet, leading to a stronger scent that can be detected on the breath or sweat.

Apart from the smell, other symptoms may indicate ketone buildup in the body, including increased thirst, frequent urination, confusion, and fatigue. In severe cases, it can lead to a medical emergency called diabetic ketoacidosis. Therefore, it is vital to monitor the body’s ketone levels and seek medical attention when necessary.

Many factors, such as diet and exercise, can affect the production of ketones in the body. For instance, a low-carb, high-fat diet like the ketogenic diet can cause significant weight loss due to the increased production of ketones, leading to their release in breath and sweat.

In the past, ketones were considered waste products or byproducts of fat metabolism. Still, in recent years, research has shown their potential benefits, such as improving cognitive function, treating neurological disorders like epilepsy, and reducing inflammation.

It is crucial to understand the distinct odor of ketones and its potential implications on overall health. Regular monitoring and maintenance of appropriate ketone levels can improve overall wellness.

If you smell something sweet and fruity, it might just be your body entering ketosis or someone nearby eating a questionable fruit salad.

Sweet Fruity Smell

The distinct scent of ketones is usually described as pleasant and sweet, like fresh fruit. It is similar to the smell of ripe apples, pears or berries, even though it is created in the body. This “fruity” odour happens when fat is burned for energy, instead of glucose. It can be noticed on someone’s breath, sweat or urine. But, too much of it can lead to dangerous medical problems, like diabetic ketoacidosis.

Not everyone can smell it; some may find it sickly sweet or unpleasant. Also, other things like dehydration, stress and poor hygiene, can affect the strength and character of the smell. So, just because you can smell a fruity smell, doesn’t always mean ketones are present. Doctors usually test for blood or urine ketone levels to get an accurate diagnosis.

Nail Polish Remover Odor

The scent of nail polish remover is a key indicator of ketones. Ketones are compounds with a strong, pungent odor like acetone or nail polish remover.

This smell comes from fat burning in the body. It can be strong on the breath and in urine when fasting or exercising for a long time.

It’s important to remember that this odor is usually safe. But if it’s with other signs like confusion or belly pain, a doctor should check it out.

Musty Smell

Ketones produce a scent often described as moldy or damp. Folks call it a musky aroma. It emanates from the breath or urine of people with high ketone levels. Acetoacetate breaking down into acetone creates this musty smell. It’s like the odor of mold and mildew, but unpleasantly sweet. Factors such as age, diet, and genetics can impact the intensity of this smell.

How to Test for Ketones?

In order to determine the presence of ketones in the body, one can perform a test known as Ketone Testing.

  1. Obtain a Ketone Testing Strip
  2. Wash Hands with Soap and Water
  3. Collect Urine Sample in a Clean Container
  4. Immerse testing strip into the Urine Sample
  5. Wait for the stipulated amount of time
  6. Compare the Color of the Strip against the Color Scale provided on the packaging

It is important to keep in mind that the concentration of ketones in the body can vary depending on factors such as diet, exercise routine, and overall health.

Research has shown that excessive ketone production in the body can lead to a condition known as diabetic ketoacidosis. (Source: American Diabetes Association)

Why go to the doctor for a urine analysis when you can just sniff your ketone breath and confirm you’re in ketosis?


Uroscopy is the commonly used term for analyzing and measuring substances in urine. In medical terms, Urinalysis involves a range of diagnostic tests done on a urine sample.

The table below displays data collected through Urinalysis tests:

Test Name Normal range Potential Causes for Abnormal Results
Color Straw-colored yellowish hue Dehydration, liver disease, and some medications can lead to changes in urine color.
Odor Faint or pungent-sweet odor If the urine smells strong, it may indicate problems with kidneys or metabolic disorders.
pH level 4.5-8.0 sometimes varies within this range depending on food intake. Infections like UTI, diet high in alkaline ash producing foods can change the pH level significantly from its normal value.

It’s noteworthy that Urinalysis can detect various conditions such as kidney disease, urinary tract infections (UTIs), liver problems, and diabetes. Be sure to follow your doctor’s advice about testing intervals and practices.

In conclusion, regular laboratory testing like urinalysis is essential for prevention and early diagnosis enhancement.

Blood Tests

Lab tests are a must for tracking ketosis! These tests check the amount of Beta-hydroxybutyrate (BHB) in your blood. Typically, a finger prick is used to get a sample, which is then tested with a special meter. This device reads the BHB level in mmol/L. It may use electrochemical or colorimetric analysis.

Note: Not all meters test BHB levels. Some measure Acetoacetate (AcAc). This info can be very different from BHB results. Be sure to check with your healthcare practitioner or pharmacist when selecting a device for proper evaluation and monitoring of ketone-related health conditions.

Breath Tests

Using a Ketone breathalyzer is a great way to measure ketones. This method looks at the amount of acetone in exhaled breath, and can show ketone levels in your body. It’s fast and easy, and much less painful than other testing methods.

Simply blow into the mouthpiece for the right amount of time. The device will show how many milligrams of acetone are in your breath. You can do this process several times a day, or as your doctor suggests.

Be aware that dehydration or drinking alcohol can change ketone levels. So, keep an eye on those variables before you take the test.

Breath tests are super helpful for people on a low-carb or keto diet, and those with type 1 diabetes. They’re not expensive, and they’re easy to use. Always speak to your doctor before using any testing method to monitor your health regularly.


Ketones, a compound made by our liver when glucose is absent, have a unique smell. It can be sweet and fruity or like nail polish remover. It can even have a metallic scent. This odor can signal a serious medical issue, such as diabetes or ketoacidosis.

If you smell ketones in your breath or urine, it’s important to seek medical help right away.

Frequently Asked Questions

Q: What are ketones and why do they smell?

A: Ketones are chemicals produced by the body when it burns fat for energy. In large amounts, they can cause a fruity or sweet smell.

Q: What do ketones smell like?

A: Ketones can have a fruity, sweet, or acetone-like smell, similar to nail polish remover.

Q: What conditions can cause ketones to build up in the body and cause a smell?

A: Ketones can be produced in the body during fasting, low-carbohydrate diets, diabetes, or alcoholism.

Q: Is the smell from ketones harmful?

A: The smell itself is not harmful, but it can be a sign of a serious medical condition, such as diabetic ketoacidosis, if accompanied by other symptoms such as nausea, vomiting, and difficulty breathing.

Q: How can I test for ketones in my body?

A: You can test for ketones in your urine using over-the-counter test strips. However, it’s important to follow up with a healthcare provider if you have a positive test result.

Q: How can I prevent the buildup of ketones in my body?

A: Eating a balanced diet, exercising regularly, and managing underlying medical conditions such as diabetes can help prevent the buildup of ketones in the body.