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Exogenous Ketones: When and How to Supplement With Ketones

Exogenous ketones are one of those products that seem too good to be true. Can you just take a pill or a powder and instantly get the benefits of ketosis?


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Well, it’s not that easy. But if you’re interested in the benefits of a ketogenic diet, exogenous ketones are definitely something to look into.

These supplements come in different forms and you can use them for different purposes, from reducing keto flu symptoms to enhancing physical and mental performance.

Read on for a deep dive into the different types of exogenous ketones, how they work, how to take them, and more.

What Is Ketosis?

Exogenous Ketones

Ketosis is a metabolic state where your body uses ketones (instead of glucose) for energy. Contrary to what many people assume, your body can run remarkably well without relying on blood glucose or blood sugar for fuel.

You’re in a state of ketosis when your body is running on energy produced by its own ketones, but you can also get there with exogenous ketones. Ketosis can lead to a host of health benefits, from lowering chronic inflammation to fat loss and muscle maintenance.

The ketones your body makes are called endogenous ketones. The prefix “endo” means something is produced inside your body while the prefix “exo” means it’s derived outside of your body (as in a supplement).

If you’d like to learn more about nutritional ketosis, what ketones are, and how to benefit from these, you’ll want to read through these helpful guides:

Types of Exogenous Ketones

If you’ve read the ultimate guide to ketones, you’ll know that there are three different types of ketones your body can make in the absence of carbohydrates, typically from stored fat. They are:

There are also ways to get ketones easily from exogenous (outside of your body) sources. Beta-hydroxybutyrate is the active ketone that can flow freely in blood and be used by your tissues — it’s the one that most ketone supplements are based on.

Ketone Esters

Ketone esters are in a raw form (in this case, beta-hydroxybutyrate) that’s not bound to any other compound. Your body can use these faster and they’re more efficient at raising blood ketone levels because your body doesn’t have to cleave the BHB from any other compound. However, there are some trade-offs.

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Most users of traditional ketone esters claim they don’t enjoy the taste, to say the least. Gastric distress is also a very common side effect.

Ketone Salts

Another form of exogenous ketone supplements is ketone salts, available in both powder and capsule forms. This is where the ketone body (again, typically beta-hydroxybutyrate) is bound to a salt — usually sodium, calcium, magnesium, or potassium. The BHB may also be bound to an amino acid such as lysine or arginine.

While ketone salts don’t raise ketone levels as quickly as ketone esters, the taste is much more palatable and the potential side effects (such as loose stools) are lessened. This is the type of ketone supplement that works well for most people.

MCT Oil and Powder

MCT (medium-chain triglyceride) oil, and other medium- to short-chain fats can be used to help boost ketone production as well, albeit through an indirect pathway[*].

While your body can use BHB from ketone salts or esters immediately for energy, your body has to transport MCTs to your cells to be broken down. From there, your cells make ketone bodies as a byproduct and only then can you use them for energy.

MCT oil is a great way to get extra fat into your diet. It’s tasteless and versatile, so you can use it on everything from your salad to your morning latte.

The downside to MCT oil for ketone production is that using too much can result in an upset stomach[*]. Anecdotally, fewer people experience stomach upset with MCT powder.

Types of exogenous ketones

Why Use Ketone Supplements?

Exogenous ketones are valuable when eating a fully keto diet is not realistic or when you want the benefits of keto without restricting carbs as much.

Although it’s better to burn ketones your body produces (endogenous ketones), there are times when you need a little help raising your blood ketones. Here are just a few examples of why you might want to use exogenous ketones:

  • When you eat a few more carbs than you should: Ketone supplements can provide you with the energy and mental clarity of ketosis without the restriction.
  • Holidays and travel: Supplements can help when following a strict keto diet isn’t realistic.
  • When your energy is low: This is usually when you’re first transitioning into ketosis; using supplements can give you the boost of mental and physical performance you need.
  • In between keto meals: They can offer more energy and mental clarity.
  • For athletes who typically rely on carbs for performance: BHB powder or pills can offer a clean, efficient form of energy that can fuel your training sessions and allow you to stay in ketosis, unlike carbohydrates.

When to Use Exogenous Ketones

Exogenous Ketones


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Now that you know what exogenous ketones are, take a look at the types of situations in which this supplement may come in handy for you. There may be more uses than you think.

To Stimulate Weight Loss

Weight loss is probably the number one reason most people want to get into ketosis. Exogenous ketone supplementation doesn’t make you magically burn body fat, but it can help raise your ketone levels.

How to Use: Add a scoop of powder or one dose of BHB capsules to boost your body’s ability to utilize ketones and stored fat as energy.

To Avoid the Keto Flu

When you transition from eating lots of carbs to the ketogenic diet, unwanted side effects can occur.

These often include low energy, bloating, irritability, headaches, and fatigue. This is because your body is in between burning carbs and burning ketones. It hasn’t become efficient at producing ketones from your fat stores and using them for energy yet.

The good news is that you can use exogenous ketones to bridge the gap. While your body is getting used to producing ketones, you can supply it with energy to reduce the common side effects of your keto transition.

How to Use: Split into smaller doses of 1/3 to 1/2 of a scoop or a 1/3 to 1/2 dose of capsules and spread throughout the day for 3-5 days while transitioning to ketosis.

For Endurance Exercise Benefits

When your body faces the energy demands of physical activity, there are three different energy systems it can use. Each system requires a different type of fuel.

If you engage in explosive activities, such as sprints or quick movements, your energy comes from ATP (adenosine triphosphate). This is a high-energy molecule your body stores for future use. However, your body only has a certain amount of ATP available, which is why you can’t be maximally explosive for more than 10-30 seconds.

When you run out of ATP, your body begins making energy from glycogen, circulating glucose, or free fatty acids. Some of these processes are dependent on using oxygen for energy. However, when you take exogenous ketones, your body can use that energy immediately with lower oxygen utilization[*].

This translates well to endurance exercise performance, where a big limitation is the amount of oxygen that is available for metabolism (VO2max)[*].

How to Use: Take a single scoop before a workout that will last 45 minutes or longer. Take another 1/2 scoop for each additional hour. This is a winning strategy for training sessions as well as competitive marathons, triathlons, and ultra runs.

For Mental Productivity

Your brain has a very effective means of keeping foreign substances out. This is called the blood-brain barrier. Because your brain consumes 20% of your body’s overall energy, you need to make sure it’s fueled appropriately.

Glucose can’t cross the blood-brain barrier by itself — it relies on glucose transporter 1 (GLUT1). When you eat carbs, you get swings in the energy that is available to cross the blood-brain barrier using GLUT1. And it’s these swings that lead to bouts of energy, followed by periods of brain fog.

Ever feel mentally foggy after you eat a carb-dense meal? That’s the dip in energy and numerous metabolic processes trying to shuttle glucose around your body. Ketones are moved about by a different type of transporter: monocarboxylic acid transporters (MCT1 and MCT2). Unlike GLUT1, the MCT1 and MCT2 transporters are inducible, meaning that they become more efficient when more ketones are available[*].

You can have a constant supply of energy to your brain just by taking more ketones, with no other processing needed. But if you’re not always in a state of ketosis, you won’t always have a supply of ketones for the brain.

This is when taking exogenous ketones can really help with your brain’s energy levels. Taken on an empty stomach, they can cross the blood-brain barrier to be used as a fuel source.

How to Use: Take a scoop of exogenous ketones or one dose of BHB capsules on an empty stomach for 4-6 hours of mental energy enhancement.

Use Ketone Supplements for Energy, Ketosis, and Performance

Exogenous Ketones

Exogenous ketones are one of the most popular keto supplements for good reason. They’re a clean energy source that offer a variety of potential benefits such as fat loss, higher levels of athletic performance, and increased mental clarity.

You can take ketone esters or salts, although salts tend to be more palatable. Some ketone salts come in different flavors and mix easily into water, coffee, tea, and smoothies. Try them today and get ready to reap the benefits.


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