Do Exogenous Ketones Break a Fast?

Some of you might know that intermittent fasting and keto are the easiest ways to lose more fat and make your diet life much better.

However, after a few days of fasting, you’re already starting to experience lagging cognitive function, low physical energy, and in dire need of a pick-me-up state. 

Then, you reach out to your solution, which is exogenous ketones supplements. 

This should give you a good amount of energy, right?

But then, many questions come up.

Shouldn’t you only be drinking water while fasting? Would it be okay if you take exogenous ketones? Won’t this break your fast? 

We are telling you that those are valid questions, and we’ll answer that in this article. 

What are Exogenous Ketones?

When you limit your carbohydrate consumption and keep your protein intake to a moderate amount, your body switches from using sugar to utilizing fats as an energy source, this is the process called ketosis. (1) 

The liver converts your stored fats into ketones, which are molecules that the body uses as fuel when there aren’t enough carbohydrates in your blood. 

When in ketosis, the body is burning ketones for energy. 

Exogenous ketones are the term used to refer to the type of ketones that are synthetically produced outside of the body.

The type of exogenous ketones commonly used for keto is beta-hydroxybutyrate salts (BHB) salts, and they are designed to increase the levels of ketones in the body.

Why Taking Exogenous Ketones While Fasting?

The truth is these supplements are quite popular with people on the keto diet and intermittent fasting. 

They are known to help you get into ketosis faster and minimize the side effects you may feel when doing keto. 

Here are some of the known benefits of exogenous ketones on intermittent fasting:

Boost your energy levels.

Exogenous ketones increase the levels of ketones in the body. The higher the level of ketones are, the more energy you’ll have.

Because of this, one of the most popular benefits of exogenous ketones is they can surely make you energetic and resolve any energy-related issues you might experience during fasting. 

Decrease your appetite.

One of the main reasons why you go on a fast is to lose weight. Unfortunately, it can be challenging to stick to your fasting schedule if you have lots of appetites.

The good news is, taking exogenous ketones can come with a decreased appetite, which means you will eat less.

And when you eat less, it will be easier for you to lose weight. (2)

Improves insulin sensitivity.

Exogenous ketones are also said to improve insulin sensitivity. (3) 

Insulin is the type of enzyme that reduces blood glucose levels by facilitating glucose movement from the blood and into your cells, where it can either be burnt for energy or stored as body fat. 

So, how can exogenous ketones help in fat loss? 

When there’s a high insulin level in your blood, the fats may not be able to add energy to your body. 

Exogenous ketones help improve insulin sensitivity, which can keep blood insulin levels low. (4) 

Can Exogenous Ketones Break Your Fast?

We will keep the answer plain and simple. 

“No, exogenous ketones won’t break your fast.”

Therefore, it’s safe to take exogenous ketones when fasting. 

You see, when your body is in the fasting state, it mobilizes fats and turns them into ketones. 

In short, there are already ketones in your blood levels. 

When you take exogenous ketones to help you get into ketosis faster, you’re only adding more of the same type of substance already present in your body during fasting. 

As a result, there will be no metabolically changes will occur. 

But of course, the result will depend on the type of ingredients the supplement has. 

If, in addition to exogenous ketones, the supplements also contain lots of fillings, additives, and sweeteners, which can increase your carbohydrate consumption, that will be the time that you’ll get kicked out of ketosis. 

Because of this, it’s essential that you carefully choose which exogenous ketones supplements to take. 

Other Keto Supplements You Can Take While Fasting

Aside from exogenous ketones, there are other types of keto supplements that you can take while fasting. These include: 


If you’re just starting on your keto diet, you’ll pee a lot to the point that you’ll be losing electrolytes. 

To avoid electrolyte imbalance, it’s recommended that you take keto electrolyte supplements to remove some side effects associated with electrolyte deficiencies. 

C8 MCT Oil

Like exogenous ketones, MCT oil is considered an instant fuel when on the keto diet. 

This is because the liver rapidly converts them into ketones, which you can readily use for energy. 

If you’re looking for the most potent form of MCT oils, it’s not other than the C8 MCT Oil as it is more rapidly metabolized than long-chain triglycerides (C10 and C12). 

Aside from the energy boost, MCT oil has also been linked to suppressed appetite and enhance cognitive functions. 

The great thing about these supplements is they come in either powder or oil form, so you can easily incorporate these into your diet.

The fact that they are tasteless is a big bonus too!


Magnesium is a critical element in different body functions including muscle relaxation and contraction, nerve function, bone formation, and heart rhythm. 

Since it’s also involved in AT-generating processes, it can also significantly affect your energy levels. 

Some Final Words

Exogenous ketones, especially beta-hydroxybutyrate salts, won’t break your fast, so they are safe to have during fasting. 

But as mentioned, you should pay extra attention to the type of ingredients and the supplement’s nutritional content. 

Since electrolytes are one of the safest supplements that you can also take while fasting, it’s okay to take BHB salts. 

However, you should stay away from supplements that contain too many fillers or sweeteners so you can stay in your fasted state. 

If you are looking for right exogenous ketones supplements, here is our buying guide on many brands and products.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top