What Are Exogenous Ketones?

In order to experience the maximum benefit of the ketogenic diet, your body needs to enter a state of ketosis and then it needs to stay there. This requires you to make certain adjustments to your diet such as significantly reducing your carbohydrate intake and increasing your fat intake. By reducing your consumption of carbohydrates, your body will have no choice but to start burning fat for fuel and that will trigger ketosis.

Ketones, also known as ketone bodies, are byproducts of the process through which the body breaks down fats for fuel in the absence of carbohydrate energy. As such, ketones are a natural substance produced in the body, but there are also supplemental forms available.

When they are produced naturally in the body, ketone bodies are referred to as endogenous ketones. Supplemental ketones, on the other hand, are known as exogenous ketones – these are ketones that are produced artificially and frequently combined with other substances to create a dietary supplement. Exogenous ketones are available in the form of a capsule, pill, or powder and they are a popular choice for ketogenic dieters as well as athletes and bodybuilders.

If you are considering taking exogenous ketone supplements, take the time to learn everything you can about them. Keep reading to learn the basics about exogenous ketones including what they are, how they may benefit you, where to find them, and how to take them.

Exogenous ketone supplements offer numerous potential benefits which may include weight loss, enhanced cognitive performance, and improved health and longevity. Most notably, however, they provide support for athletes following the ketogenic diet.

In order to understand what exogenous ketones are and how they work, you must first know about the different types of ketones. When the body enters a state of ketosis, it produces several different kinds of ketones, namely:

• Acetoacetate (AcAc)
  
• Beta-hydroxybutyric acid (BHB)
  
• Acetone

As you may remember, acetoacetate is the first ketone formed in the body, and it is converted into beta-hydroxybutyric acid and then into acetone. Beta-hydroxybutyric acid is the active form of ketones that flows freely in the blood for uptake by cells and tissues. Because it is the most useful form of ketones, this is the ketone on which most exogenous ketone supplements are based – this is why exogenous ketone supplements are also sometimes called BHB supplements.

Though endogenous ketones are proven to provide the greatest benefit, there are certainly times when ketone supplements may be beneficial. One of the main reasons people consider the ketogenic diet is because they want to burn fat and lose weight. Taking exogenous ketones can, to some degree, provide the fat-burning benefit of the ketogenic diet without reducing your carbohydrate intake quite so drastically. It also enables you to skip the sometimes-unpleasant transition into ketosis during which you might experience symptoms of keto flu.

Exogenous ketones come in various forms, here is a quick overview of the different types:

• Ketone Esters – These ketones are formed when a synthetic ketone compound is bonded to an alcohol compound. While they are technically synthetic, ketone esters are metabolized in the liver into raw ketones. The main benefit is that they provide instant energy, but the taste can be very unpleasant.
  
• Ketone Salts – This type of ketone forms when raw ketones are bonded to various salts like potassium, sodium, or calcium to boost absorption. They may not raise ketone levels as high as ketone esters, but they have a better taste and lower risk for gastrointestinal side effects.
• Ketone Oils – Various oils such as MCTs and other fats may not directly provide ketone energy, but the breakdown of these oils produces ketones as a byproduct which can then be used for energy. The downside is that they are calorie-dense and may not raise ketone levels as much as ketone esters or salts.

In addition to three types of ketones, you may also come across supplements like raspberry ketones. It is important to realize that these supplements may offer nutritional support for ketosis, but they do not actually increase ketone levels in the body.

Though the ketogenic diet has been scientifically proven to speed weight loss, boost energy, improve mental focus, and suppress hunger and cravings, the diet itself can sometimes be difficult to stick to. You must also consider that the body will go through a transition period before entering ketosis which might produce undesirable symptoms such as fatigue, headache, and irritability. The main benefit of exogenous ketones, then, is that you will experience certain benefits of ketosis without having to fully commit to the ketogenic diet or without waiting so long for it to work. Aside from weight loss, when might it be beneficial to use exogenous ketones? Here are a few situations in which you might consider taking ketone supplements:

• When you want to burn more fat
  
• When you want to enter or return to ketosis quickly
  
•  When you want to avoid the keto flu
  
• When you plan to engage in endurance exercise
  
• When you want to boost cognitive ability

To explore the first point in greater depth, understand that taking ketone supplements will not cause body fat to magically melt away. It will, however, help your body enter a state of ketosis more quickly and, once in ketosis, your body turns into a fat-burning machine. Not only does it burn through the fats you consume as part of your daily diet, but it will help burn stored fats as well.

If you’re having trouble following a low-carb, high-fat diet then taking ketone supplements might help. Whether you’ve gone off the diet for an extended period of time or you ate more carbs than usual on a single day, taking ketone supplements can help kick-start your body’s fat-burning ability by getting you back into a state of ketosis more quickly. If you take the supplement shortly after a high-carb meal, it will help to ensure that your body uses ketones for energy instead of those carbs.

The keto flu has already been mentioned as a transition period between high carb intake and ketosis. When you make significant changes to your diet, your body will go through an adjustment period, and you might experience symptoms such as headache, irritability, fatigue, low energy, and bloating. These symptoms result from the fact that your body is no longer able to rely on carbs for energy, but it has not yet completely transitioned into burning fats for fuel. Taking exogenous ketones during this transition can help you enter ketosis more quickly so you can avoid the whole keto flu phase.

Not only are exogenous ketones great for weight loss, but they can also provide support for endurance athletes. In the absence of carbohydrates, your body burns through its stored glycogen – this is particularly true for high-intensity exercise. In order to utilize stored glycogen, however, the body needs high levels of oxygen. Taking exogenous ketones prior to exercise enables the body to utilize fats as an immediate source of energy and at a much lower level of oxygen.

Aside from its physical benefits, ketosis also offers certain cognitive benefits such as improved mental clarity and focus. Taking exogenous ketones provide a direct boost of fuel for the brain, crossing the blood-brain barrier to deliver a clean source of usable energy. These effects are most noticeable when you take exogenous ketones on an empty stomach.

In addition to the benefits discussed above, taking ketone supplements may provide additional benefits such as hormone regulation, appetite suppression, blood sugar stability, and more. The key to maximizing your benefits is to enter and stay in a state of ketosis, and exogenous ketone supplements might help get you there.

Testing Your Ketone Levels

Whether you are taking exogenous ketones or just following the ketogenic diet, you’ll need to test your ketone levels to determine whether you’ve entered a state of ketosis. Once your body has entered ketosis, you should still test periodically to make sure your macronutrient ratio is producing the desired result. So, how do you test your ketone levels? There are three options:

• Blood test
  
• Breath test
  
• Urine test

If you think back, you may recall that there are three types of ketones produced in the body but beta-hydroxybutyric acid (BHB) is the form that flows most freely in the blood. Not all of the ketones in your body are BHB, however, and ketone levels in the blood may not always match ketone levels in your urine. Even so, a blood ketone test is still the most accurate of the three options.

To test your blood for ketones, you’ll need to purchase a blood meter then prick your finger to obtain a sample of blood. After inserting the strip into the meter, you’ll need to wait for about 10 seconds until you get the results. Typically, BHB levels in the blood are measured in millimolar concentration or mmol. Optimal ranges for BHB are between 1.5 and 3 mmol. Though this form of testing is the most accurate, it can also be somewhat expensive with test strips costing $5 to $10 each.

When you test your urine for ketones, you’ll be testing for acetoacetate in particular. Keep in mind, however, that you’ll only find ketones in your urine if ketone levels in the rest of the body are sufficiently high for them to spill over into the blood. As your body becomes keto-adapted, it will become more efficient at using acetoacetate, so urine testing may not be the most accurate method when testing for ketosis.

Taking a urine test for ketosis is very simple – just urinate on the test strip or pee into a cup and dip the strip. Wait for the designated period of time (usually 45 to 60 seconds) and then compare the color on the strip to the color chart. For most urine ketone tests, the darker the color, the higher the ketone level. Though it may not be the most accurate method, urine tests for ketones are easy to do, and you can purchase a pack of 120 test strips for around $20.

The third method of testing for ketones is the breath test, the least accurate of the three. A breath test for ketones relies on acetone and you can use a breath meter to test for it. All you have to do is blow into the unit, and it will show a color that correlates with acetone levels in the blood. Not only is this method the least accurate, but it also takes longer than either urine or blood tests to get a reading.

If you’re thinking about taking exogenous ketone supplements, you may be wondering where to find them. Generally speaking, you’ll find the highest number of options if you shop online. There are plenty of supplement companies out there that sell their products online, so it won’t take you long to find a handful of options.  You may also be able to find ketone supplements at your local health food store or health supply store.

As you start shopping around for ketone supplements, there are certain factors to consider. How does the product taste? What form does it come in? Is it generally well tolerated by users? You may need to do some research and read a few reviews to find the answers to these questions, but it is well worth the effort to find a high-quality product you can trust.

We also recommend products, such as KetoAF Keto Superfuel, that contain both BHB and MCT - as clinical studies show that when taken together, blood ketone levels rise higher and are sustained longer than either supplement alone. In effort to raise profits, most supplement companies sell the two products separately and give you the option to stack them together. Consumers can save money by choosing a supplement like Keto Superfuel that contain both BHB and MCT.  

If you’ve ever shopped around for dietary supplements, you know how expensive they can be. It may be tempting to save a little bit of money on a generic product, but you must realize that quality matters – in other words, you get what you pay for. But what exactly makes ketone supplements so costly?

First and foremost, you must realize that exogenous ketones (in their modern form) are still fairly new. Though synthetic ketones have been produced in labs since the 1960s, it is only somewhat recently that BHB supplements have entered the scene. Not only is BHB rather new, but it takes time and resources to produce and purify – time is money, as they say. You also have to factor in the cost of research and development incurred by whatever company is producing the supplement.

Any prescription drug or supplement comes with the risk of side effects; there is no escaping it. One of the main uses for exogenous ketones is avoiding the symptoms of keto flu, but you must realize that you might be putting yourself at risk for a trade-off – ketone supplements can also cause symptoms such as flatulence, bad breath, or electrolyte imbalance.

Not only can exogenous ketones themselves cause side effects like those mentioned, but they may also trigger side effects of ketosis itself. Some potential side effects of ketosis include the following:

In most cases, symptoms such as those listed above only last for a few days – once your body becomes keto-adapted, they will go away. If you take exogenous ketones, however, the side effects may persist for as long as you are taking the supplement. In many cases, however, proper dosage does not produce serious side effects.

Now that you know a little bit more about how to shop for exogenous ketone supplements, you may be wondering how best to take them. Here are some of the best times to take ketone supplements:

The exact timing for exogenous ketone supplements will depend on the intended purpose. If you’re looking for a quick energy boost, take the supplement in the morning on an empty stomach – the resulting energy boost should last you a good 4 to 6 hours. If you are taking ketone supplements for energy to fuel a workout, take it about 30 to 45 minutes before.

If you want to harness the fat-burning benefits of ketone bodies, you can take an exogenous ketone supplement after consuming a very carb-heavy meal to help your body return to a state of ketosis as quickly as possible. If weight loss is your goal, you can take the supplement daily, and you can also try pairing exogenous ketones with intermittent fasting to maximize your fat burn and weight loss.

Though exogenous ketones can certainly boost your results and help you enter a state of ketosis more quickly, they should not be used as a crutch. In order to reap the maximum benefit from ketosis, you should commit to and follow the ketogenic diet as closely as possible.

References:

Cox, Pete. “Nutritional Ketosis Alters Fuel Preference andThereby Endurance Performance in Athletes.” Cell Metabolism. <https://www.sciencedirect.com/science/article/pii/S1550413116303552>

“Exogenous Ketone Supplements: Review of Current Productsand Future Developments.” KetoSource. <https://ketosource.co.uk/exogenous-ketone-supplements-review/>

“Endogenous vs.Exogenous Ketones – What’s the Real Difference?” Ketogenic Supplement Reviews. <https://www.ketogenicsupplementreviews.com/blog/endogenous-vs-exogenous-ketones/>

Kesl, Shannon. “Effects of Exogenous Ketone Supplementationon Blood Ketone, Glucose, Triglyceride, and Lipoprotein Levels inSprague-Dawley Rats.” Nutrition & Metabolism. 2016; 13(9). <https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-016-0069-y>

“Raspberry Ketones – Do They Really Help with Weight Loss?” Dr. Axe. <https://draxe.com/raspberry-ketones/>

Stubbs, Brianna. “On the Metabolism of Exogenous Ketones inHumans.” Frontiers in Physiology. 2017; 8: 848. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5670148/>

“The Beginner’s Guide to Exogenous Ketones.” Keys to Ketosis. <https://keystoketosis.com/the-beginners-guide-to-exogenous-ketones/>