Dr. Anthony Gustin is a board-certified sports chiropractor, functional medicine practitioner, entrepreneur, podcast host, and founder of Perfect Keto.
Exogenous ketones are one of those products that seem too good to be true. You can just take a pill or a powder and instantly get the benefits of ketosis?
But what exactly are exogenous ketones and how exactly do they work? If you’re interested in the benefits of a ketogenic diet, exogenous ketones are definitely something to look into. Which is what this guide is all about.
Exogenous ketones 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 in-depth info about the different types of exogenous ketones, how they work, how to take them, and more.
If you are new to ketosis and don’t know much about it, it is a metabolic state where your body preferentially uses ketones (instead of glucose) for energy.
This can lead to a host of different health benefits from lowering chronic inflammation to fat loss and muscle maintenance. If you’d like to learn more about ketosis, what ketones are, and how to benefit from these, feel free to read through our guides:
If you’ve read the guide about 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:
However, there are ways to get ketones easily from exogenous (outside of your body) sources.
Beta-hydroxybutyrate is the active ketone that can flow freely in the blood and be used by your tissues, so that is the one that most exogenous ketone supplements are based off.
Ketone esters are in a raw form (in this case, beta-hydroxybutyrate) that is 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.
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.
Another form of exogenous ketone supplements come in the form of ketone “salts.” This is where the ketone body (again, typically beta-hydroxybutyrate) is bound to a salt — usually sodium, calcium, magnesium, or potassium.
While ketone salts do not raise ketone levels as quickly as ketone esters, the taste is much more palatable and the potential side effects (like loose stools) are lessened. This is the type of ketone supplement that works well just a majority of the population.
It comes in powder and capsule form.
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.
Whereas your body can use beta-hydroxybutyrate 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 downsides to MCT oil for ketone production is that too much MCTs can result in an upset stomach[*]. Anecdotally, fewer people experience stomach upset with MCT powder.
MCT oil and powder are also calorically dense compared to ketone supplements, so opt for exogenous ketones if you’re watching your caloric intake.
There are times when eating a fully ketogenic diet is not realistic or when you want to get the benefits of a keto diet without restricting carbs as much.
Here are just a few reasons why you might want to try exogenous ketones:
- When keto is too restrictive and you eat a few more carbs than you should. Exogenous ketones can provide you with the energy and mental clarity of keto without the restriction.
- Holidays and travel when a strict keto diet isn’t as realistic.
- When your energy is low — usually when you’re first transitioning into ketosis. Exogenous ketones can give you the boost of mental and physical performance you need.
- In between keto meals for 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.
- If you eat too many carbs, you can take exogenous ketones to get you back into ketosis rapidly instead of waiting 2-3 days.
#1: May Stimulate Weight Loss
Weight loss is probably the number one reason most people want to get into ketosis. Taking exogenous ketones doesn’t make you magically burn fat, but it does get you into ketosis quickly.
Exogenous ketones stimulate weight loss by increasing energy and decreasing hunger.
How to: Use a scoop of exogenous ketone powder or 1 dose of BHB capsules to help transition into ketosis or to boost your body’s ability to utilize ketones and stored fat as energy.
#2: To Get Back Into Ketosis Quickly
Not everyone can follow a very strict, high-fat, low-carb diet. For those who have done keto before, you’ll know that when you get kicked out of ketosis, it can take a while to get back in.
Not anymore. You can use exogenous ketones to put your body back into ketosis quickly and easily.
Using an exogenous ketone supplement shortly after a meal with carbohydrates will tell your body that it’s time to use ketones for energy instead of relying on carbs in the near future. Instead of eating very-low-carb for days after a carb binge, you can just take a scoop of exogenous ketones or a few days of BHB pills and get back into ketosis.
This also means you don’t have to go through the keto flu again if you happen to have the occasional carb relapse.
How to: Take half to a full serving of exogenous ketones when transitioning to ketosis.
#3: To Avoid The “Keto Flu”
When you transition from eating lots of carbohydrates 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 and hasn’t gain efficiency 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 eliminate with the common side effects of your keto transition.
How to: Split into smaller doses of 1/3 – 1/2 scoop or a 1/3-1/2 dose of capsules and spread throughout the day for 3-5 days while transitioning to ketosis.
#4: For Endurance Exercise Benefits
When your body faces the energy demands of physical activity, there are three different energy systems it can use. Each requires different types 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 to use for explosive movements, 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: 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.
#5: For Mental Productivity
Your brain has a very effective way 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 is 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 super dense carb meal? That is the dip in energy and a ton of metabolic processes trying to shuttle glucose around your body. No one wants to feel mentally foggy, so good thing there are exogenous ketones.
Ketones, however, are transported by a different type of transporter: monocarboxylic acid transporters (MCT1 and MCT2). Unlike GLUT1, MCT1 and MCT2 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 to the brain. This is when you can take exogenous ketones.
Think of one of the benefits of exogenous ketones as on-demand brain fuel. If you need some mental energy, you can take exogenous ketones on an empty stomach and they will readily cross the blood-brain barrier and be used as such.
How to: Take a scoop of exogenous ketones or 1 dose of BHB capsules on an empty stomach for 4-6 hours of mental energy enhancement.
The Takeaway: Use Exogenous Ketones for Energy, Ketosis, and Performance
As you can see, there are plenty of ways to use exogenous ketones for a variety of benefits.
You can take ketone esters or salts, although salts tend to be more palatable. In fact, some ketone salts come in different flavors and mix easily into water, coffee, tea, and smoothies.
How do you use exogenous ketones? Any results that you’ve noticed that could help someone else? Let us know in the comments below!