What are exogenous ketones? Do you need them?

You’ve probably heard about exogenous ketones, but you’re not sure if they are necessary on your keto diet. What are exogenous ketones, do you need them?

If you’re following the keto diet, reaching and staying in ketosis is going to be a very important goal for you.

It is the state of ketosis which gives the keto diet all its weight loss and health benefits.

You’ll need to stay within 20g net carbs each day.  When you do this, you’ll  be able to reach ketosis quickly. Normally within a week or two of starting the diet.

So, is there any need to supplement with exogenous ketones?

What are the claims for exogenous ketones?

What are exogenous ketones? Do you need them?

There are several companies that produce exogenous ketones. They all make fairly similar claims about their product.

At first glance, these claims seem to be good.

They all claim to be able to increase your level of ketosis.

Even when you are not limiting your carbohydrate intake.

So, you can enjoy all the benefits of the keto diet without having to super glue yourself to the strict carb limit.

But is this true or even desirable?

Further, most producers of exogenous ketones claim:

  • A quick and easy way to reach/maintain ketosis
  • A boost to your fat burning capabilities, and therefor quicker weight loss
  • Increased cognitive ability. Improved mood, focus and energy
  • Increased stamina for exercise

In other words, supplement your keto diet with exogenous ketones. This way you’ll be able to take the keto shortcut.

All the weight loss and health benefits without having to lower your carb intake.

What types of exogenous ketones are available?

What are exogenous ketones? Do you need them?

There are two types of exogenous ketones:

Ketone salts – These ketones are bound to either sodium, calcium, magnesium or potassium.

Ketone esters – An ester is a carbonyl with an ether group on the carbon atom and are common in fats and oils. It is possible to reduce the ester to ketones.

Both of these types of ketones have been proven to increase ketosis.

What is the difference between low carb induced ketosis and taking exogenous ketones?

What are exogenous ketones? Do you need them?

When following a keto diet, the very low carb allowance is insufficient to meet your daily energy needs.

To deal with this, your body will first use up all the glycogen that you have stored in your liver.

Once this store is depleted your body will switch over to its second metabolic pathway: burning fat for fuel.

It is this burning of your fat stores that produces the ketones. These  give the keto diet its name.

Ketones can be used as an alternative fuel by your body. They  are  associated with numerous health benefits as well as weight loss.

It can take from several weeks to a month or more to become fully fat adapted on the keto diet.

When you reach this stage, you are able to burn fats efficiently. You’ll also enter ketosis more quickly.

In contrast, exogenous ketones do not require time or adjustment to work in your body.

They will give you a quick ketogenic boost, which will normally last for a few hours

When we enter ketosis via diet, it is a slow and steady approach. Fat stores are utilized for energy, and the production of ketones is monitored by the liver.

The liver will produce sufficient ketones to serve our energy needs. It will not supply extra ketones if they are not required for this purpose.

The slow build up to ketosis sets this mechanism in place. That way there are no excessive amounts of unnecessary ketones produced.

Quick surge in ketone levels

However, when you consume exogenous ketones, your body is faced with a very quick surge in your ketone levels.

To attempt to keep this under control, mechanisms are triggered that do two important things:

  • Decrease the amount of fatty acids released from the fat cells, to reduce the fuel available for ketones production.
  • Increase the effects of Insulin, enhancing fat storage. This also has the effect of reducing available fatty acids.

Due to this control of ketone levels, taking exogenous ketones actually reduces rather than enhances fat burning.

So, although exogenous ketones will temporarily increase your level of ketosis, this effect does not last long.

After a few hours, your ketone levels will be due to your diet rather than a supplement.

Is there any benefit in taking exogenous ketones?

Having just said that exogenous ketones do not have a positive effect on ketosis long term, they are not completely worthless.

There are several short term conditions that can be helped by taking exogenous ketones, which can make them useful.

Keto Flu

Keto Flu is a condition that often effects people when they first start the keto diet.

It is caused by the body needing to adjust its metabolic pathway to burning fat for fuel before you’re fully fat adapted.

This brings about some unpleasant symptoms. Although they are short-lived, they are difficult to live with, and most people seek a way to alleviate or cure their keto flu.

For a full explanation of this condition see What’s the keto flu and how to avoid it

Exogenous ketone salts contain three of the minerals that are often depleted at the start of a keto diet:

  • Sodium
  • Potassium
  • Magnesium

As these minerals are depleted, the loss of them is often a trigger for the keto flu.

Taking an exogenous ketone supplement is one of the ways that you can elevate the symptoms in the first week or two.

Appetite Control

This study linked the ingestion of ketone esters with appetite suppression. The study concluded that:

Exogenous ketosis following KE drinks reduced two measures of appetite, hunger and desire to eat, compared with DEXT drinks. This occurred in conjunction with decreased levels of the hunger hormone, ghrelin. Therefore, KE drinks offer a unique opportunity to isolate and exploit the effects of ketosis on appetite without other dietary interventions.

However, the same study also pointed out that it was not clear that ketone esters could be consumed long‐term for appetite control.

Therefore, until any chronic effects are fully characterized, ketone supplements should not be used to replace dietary strategies for weight control.

So, as a short term appetite suppressant, especially when you first start the keto diet, it would seem that exogenous ketones can be of benefit.

Another well documented short term benefit is that exogenous ketones can give you an energy boost for several hours.

This seems to be especially effective if you are already well keto adapted.

Exogenous ketones and cognitive function

This is one area where exogenous ketones come into their own.

The brain has massive energy requirements, using 20% of the energy needed for the whole body.

This makes it particularly sensitive to any problems with accessing glucose.

When exogenous ketones are taken, the switch over to using ketones is very fast. This gives the brain an alternative energy supply.

Cognitive Benefits

This study looked into the link between exogenous ketones and improved cognition.

This is an area in which there is overwhelming evidence that exogenous ketones can be of benefit.

The study reports that :

It has been demonstrated in animal—and/or human studies—that ketogenic diets and supplements may have metabolism-based therapeutic potential in the treatment of several diseases, such as Alzheimer’s disease (), Parkinson’s disease (, ), glucose transporter type 1-deficiency syndrome (), amyotrophic lateral sclerosis (, ), cancer (, , , ), epilepsy (, , ), schizophrenia (, ), anxiety (, ), autism spectrum disorder (), and depression (, , ).

It’s important to note that this study found ketone supplements to be equally useful in the treatment of neurodegenerative diseases and psychiatric disorders.

The authors of the study go on to say that sometimes it is difficult for some to stay within the strict 20g carb limit of the keto diet.

In this case, a supplement of exogenous ketones is of benefit.

They further suggest a mix of ketone ether or ketone salts with MCT oil. This mix offers an enhanced cognitive benefit for psychiatric disorders such as depression and anxiety.

Thus, it is possible that exogenous ketone supplementation-induced ketosis may be an effective therapeutic tool against psychiatric diseases.


There is evidence that for fat burning and weight loss it is better to achieve this through the keto diet.

Diet alone has more benefits than combining diet with exogenous ketones.

This is due to the fact that exogenous ketones raise ketone levels much faster than diet alone.

This triggers a response in the body which limits fat burning and at the same time increases sensitivy to Insulin.

Increased sensitivity to Insulin will also have the effect of reducing overall fat loss, as storage of fat will be increased.

However, for a quick mood boost or some extra energy, exogenous ketones can be of benefit.

The effects of which can be felt for several hours.

Further, if you suffer from depression, anxiety or several other mood disorders, exogenous ketones can be very helpful.

It has been shown that they decrease the effects of these conditions.

There is also evidence that exogenous ketones can lessen the effects of neurodegenerative diseases.

So, if you want long term weight loss, its more useful to continue to adhere to the keto diet. Attempting to shortcut this process with exogenous ketones won’t be doing you any good.

In fact, it will slow your progress.

However, if you want to boost your energy levels, focus and mood, there are enormous benefits for you in including exogenous ketones in your routine.

Add some MCT oil to your exogenous ketones and you will enhance these benefits even further.


Click here for a review of the best exogenous ketones






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