Exogenous ketones (also called ketone esters) are supplements that contain the metabolized form of fat your body relies on when it’s in a state of ketosis.
Usually, the only way to achieve high levels of ketones in your blood is to either fast or to eat a diet extremely low in carbohydrates.
Exogenous ketones, because they come from outside of your body, allow you to create a state of ketosis even when your diet doesn’t support it.
Ketone supplements can act as weight loss supplements because of the fat loss involved in the state of ketosis. They’re quite popular among ketogenic dieters when they need to “cheat” their diet with a meal that’s high in carbohydrates or protein, but there is also some evidence that ketone esters can be helpful for athletic performance, even in the absence of a ketogenic diet.
If you need a way to maintain ketosis during periods where it’s difficult to stick to a keto diet, or if you are looking for an extra boost to your endurance performance during long, continuous efforts, our researchers have ranked the ten best exogenous ester supplements that will keep your body burning fat for fuel and maintaining a steady and reliable energy source.
1. HVMN Ketone
HVMN is bolstered by a range of scientific studies testifying to its efficacy. The taste is harsh, but the effects are impressive, even if you aren’t on a ketogenic diet.
After years of development and scientific reserach, this product has finally hit the market in 2018. This high-end exogenous ketone supplement is the best choice when it comes to both sport and cognitive performance.
2. Zhou Keto Drive
Zhou Keto Drive provides a shot of vitamin A alongside three salt forms of ketone esters: calcium, sodium, and magnesium beta-hydroxybutyrate.
These salt forms of ketone don’t have quite the harsh taste as liquid ketone esters do, which makes it a far better option if you can’t stomach a liquid supplement.
Since it’s sweetened with a little stevia and citric acid, this ketone ester supplement goes down much easier.
3. KetoSports KetoForce
KetoSports KetoForce is a liquid-based ketone supplement, but it’s still based on ketone ester salts—they are just dissolved in the solution.
This makes it easy to mix into a shake or a smoothie, and the fact that this supplement only uses potassium as a salt ion makes it advantageous for people trying to watch their sodium.
The taste is not the greatest, but if you can stomach it, it’s a highly effective ketone ester source.
4. Perfect Keto Base
Perfect Keto makes a powder-based ketone supplement that’s flavored with stevia and natural chocolate flavor.
It goes the job done, but as a result of using sodium salts of beta-hydroxybutyrate, its sodium content is pretty hefty. This could prove to be an issue if you are trying to keep your salt intake low to control your blood pressure. That aside, it’s a great product.
5. Left Coast Performance Keto Burst
Left Coast Performance makes a pretty clean ketone supplement that’s flavored with monk fruit extract, stevia, natural flavoring, and ascorbic acid (vitamin C).
The sodium content is pretty high, which is bad news if you’re looking to keep your salt intake low, but aside from that it’s a pretty solid product.
6. Vitamonk Ketosene
Vitamonk Ketosene is a simple and clean source of ketone esters that uses a balanced array of ketone ester salts alongside stevia and some natural flavoring to spice up the typically-foul ketone ester taste.
It’s a mainstay for keto fans who aren’t looking for anything fancy, and is deserving of a look if that sounds like what you need.
7. Zenwise Health Keto-Lift BHB
It’s a good choice if you want lower sodium but the advantages of multiple different ketone ester salts.
8. Giant Keto Exogenous Ketones
Giant Keto is more than just an exogenous ketone—it’s a comprehensive supplement to help you perform optimally when on a low carb or ketogenic diet.
To this end, it has additional ingredients like selenium, vitamin K, and vitamin D, which you might be lacking if you are on a restrictive diet.
This does mean the ketone ester content is not quite as high, pound for pound, but overall it’ll still be a good choice for some people.
9. Kegenix Prime
Kegenix Prime offers something a little unusual: a combination of ketone ester salts and MCT oil in the same supplement.
While this has some theoretical advantages, the fact that Kegenix Prime mixes these together in a proprietary blend with the MCT oil makes it slightly tricky to figure out the precise ketone ester dosage, and it necessarily dilutes the raw ketone ester content. It’s an okay option if you want the benefits of MCT oil alongside your ketone esters, though.
10. Julian Bakery InstaKetones
InstaKetones uses a ketone ester salt that’s heavy on calcium and sodium, and is flavored with luo han guo as opposed to the usual stevia.
It’s got taurine for an extra workout boost, but the taste is a real buzzkill and many users find it’s not as effective as they’d like.
Exogenous ketone supplements benefits and side effects
Exogenous ester supplements have two primary uses: first, as a way to keep your body in a state of ketosis even if you have to “cheat” a bit on some of your meals from time to time, and second, as a way to leverage ketogenic energy pathways for better athletic and cognitive performance, even if you are not on a ketogenic diet.
While the health benefits of a keto diet are widely reported, the potential performance advantages of ketone esters outside of the usual ketogenic diet routine are less well-known.
Your blood levels of ketone are the best indicator of your ketogenic status. While monitoring urine levels of ketones is the most popular and practical method of assessing ketogenic status, it’s not the best predictor of how effective your ketogenic diet (or supplement) actually is.
Research on ketogenic diets in epileptic children has found that the best predictor of success on the diet is not urinary ketone levels, but blood levels of beta-hydroxybutyrate (1).
For this reason, if you need to boost your ketosis state, the easiest way to achieve this in short order is to increase your beta-hydroxybutyrate content. One way to do this is restricting your diet even more, but simply taking a ketone ester is a lot faster.
Exogenous ketones could protect your brain from neurodegenerative diseases. As many people know, the ketogenic diet was first developed to treat intractable epilepsy in children.
Even today, the reasons why it works so well are shrouded in mystery, but given that it does work, there’s incontrovertible evidence that ketones have a profound effect on your brain function.
Emerging scientific evidence suggest that the ketone esters that your body uses for fuel during ketosis could protect your brain from chronic neurodegenerative diseases like Alzheimer’s.
One study, published in 2005 in the journal Nutrition & Metabolism, used lab mice to study how a state of ketosis (characterized by high levels of beta-hydroxybutyrate—aka ketone ester—in the blood) affected the buildup of damaging plaques (2).
In the paper, the researchers described their experiment: two groups of mice bred with a specific genetic trait to predispose them to the mouse equivalent of Alzheimer’s disease were fed either a high carbohydrate and low fat diet (the usual procedure for lab mice), or a strongly ketogenic diet high in fat and very low in carbohydrates.
After 43 days, the researchers dissected the brains of the mice to test them for levels of beta amyloid, a plaque protein closely linked to brain tissue degeneration.
They found that the mice in a state of ketosis had 25% less beta amyloid buildup compared to the mice on the standard diet, and the main discriminating factor between the group was the level of ketone esters in their blood. This suggests that, in addition to short-term cognitive benefits, ketone esters could protect your brain in the long run.
Exogenous ketones can keep you in a state of ketosis even when you aren’t on a ketogenic diet. Given the extreme difficulty of adhering to a true ketogenic diet, it would be advantageous if you could get the same benefits without the highly restrictive macronutrient requirements. Fortunately, a ketone ester supplement appears to offer this possibility.
A large and comprehensive scientific study published by researchers at the University of Oxford in the UK demonstrated that either a liquid form ketone ester or a ketone salt, when taken in an adequate dosage, could maintain similar blood levels of ketones as are found in a ketogenic state, even when preceded by consuming a traditional meal that does not follow ketogenic diet requirements (3).
To actually accomplish this long-term, it takes fairly regular ingestion of ketone ester, as each dose only raises blood levels of beta-hydroxybutyrate for about three to four hours.
Hence, this is why ketone esters are more popular as a way to “cheat” on a ketogenic diet versus a stand-alone solution.
Exogenous ketones can improve endurance exercise performance, even on a normal diet. While a ketogenic diet has been toyed with by some ultra-endurance athletes, it doesn’t appeal to many high-intensity sport athletes because it requires severely curtailing your intake of carbohydrates, the primary fuel for short, intense exercise.
However, recent research suggests that a ketone ester supplement could boost your exercise performance by inducing ketogenic-like metabolic effects, even when you are on a regular diet.
A series of studies described in the journal Cell Metabolism in 2016 detailed the biochemistry behind the use of ketone esters to improve exercise performance (4).
In short, a ketone ester supplement ingested before high intensity aerobic exercise allows you to maintain the same exercise intensity, but with less fatigue accumulation.Even though glycogen is available in the muscles, your body burns ketones instead, sparing energy and postponing fatigue.
Exogenous ketones could prove incredibly valuable to marathoners, cyclists, swimmers, and other endurance athletes when incorporated into their workouts.
Exogenous ketones are so new that there are no clinical trials that would be able to detect or report any side effects directly.
The most obvious side effect of any ketone ester supplement is simply its bad taste—ketone esters have a reputation for having a pretty foul taste, especially when they are in their liquid ester form.
Journalists from Business Insider reported gagging and tearing up when they tried one of the latest liquid ketone ester supplement thanks to its pungent taste (5).
The ketogenic diet itself has a few reported side effects, such as rare cardiac complications and selenium deficiency, but it’s not clear whether a ketone ester supplement would cause similar problems when consumed with an otherwise normal diet (6).
For most people, a ketone ester is most effective at boosting you into a ketogenic state by taking a dose of 12 to 24 grams of beta-hydroxybutyrate, either in liquid ester form or in a salt.
This will raise your blood levels of ketone ester for about three to four hours, after which they will return back to normal.
For most cognitive and physical performance tasks, this should be sufficient, but if you are working through a massive project or competing in an ultraendurance event, you might need a boost halfway through.
Exogenous ketones are supplements that offer the promise of extending the benefits of a ketogenic diet beyond the usual highly restrictive requirements of very high fat intake and very low carb intake.
If you are trying to stay in a state of ketosis, a ketone ester supplement can keep you there even if you have to cheat for a meal or two.
Ketone ester intake on a regular basis might not only improve cognitive performance, but have a neuroprotective effect, staving off degeneration of your brain tissue.
Most interestingly, ketone esters appear to improve endurance exercise performance, without the requirement of actually adopting a ketogenic diet.
There’s sure to be more research on ketone ester supplements in the coming years, but they already show a lot of promise when it comes to advancing the benefits of ketosis beyond the ketogenic diet itself.