Exogenous Ketones Comparison (Ketone Esters, Ketone Salts and C8 MCT Oil) – Experiment Results

What Exogenous Ketone Supplements Are

Exogenous ketone supplements are supplements that boost levels of ketones in the blood.

Exogenous ketone supplements include ketone esters, ketone salts, MCT oils, and 1,3-butanediol.

You can also find supplements and foods that contain the above as “active ingredients”. For instance, there are MCT powders (containing C8 MCT oil or mixed MCT oil). There are also snacks and bars available (like the Ketone Bar) which contain these.

However, the ability of each powder and snack to boost ketone levels relies on the ketone ester, ketone salt, or MCT it contains. So we designed our experiment to test each of these ‘active ingredients’ in its isolated/ pure form.

What the Experiment Was and Why We Did It

We wanted to know how well each exogenous ketone supplement could boost levels of beta-hydroxybutyrate. This is also known as BHB ketone. It is the ketone body that is measured by handheld blood meters and often used in studies.

To do this, we tested blood ketone and glucose responses to the most popular exogenous ketone supplements at the time to know for sure.

How the Experiment Was Run

What Was Tested?

For the experiment, two participants took four days’ worth of baseline readings. These measured blood levels of glucose and BHB ketone.

Next, participants tested one exogenous ketone supplement per week. Seven days was left between each test as a ‘washout period’. This made sure that there were no leftover effects from one test spilling over to another.

Here are the ketone supplements that were tested:

1. HVMN Ketone Ester (now discontinued – it was licensed from TΔS)
2. KE4 ketone Aid Ketone Ester
3. KetoCaNa Ketone Salt
4. Pruvit Keto OS Max Ketone Salt (now discontinued)
5. Ketosource Pure C8 MCT Oil

Table 1: The five ketone supplements used in the experiment and their dosages

*The HVMN and Pruvit products listed here are now discontinued
**One UK tablespoon is now known to be 15ml. This has been corrected on the nutrition label for Pure C8 MCT Oil. A dose of 18ml was used in this experiment.

The Experiment Results

Average Blood BHB Ketone Responses

Figure 2. Average blood BHB ketone levels following consumption of each exogenous ketone supplement

As expected, we saw the ketone esters boost BHB ketone levels much higher than the ketone salts or C8 MCT oil.

On average, both the esters and salts had their maximal effects after 30-60 minutes. This is similar to results from published studies.

In contrast, it took 120 minutes on average for C8 MCT oil to do the same. This is longer than the expected results for C8 MCT oil.

One possible explanation for this is that both participants were on ketogenic diets during the experiment. On average, the participants were at or near appetite reduction ketosis at the start of each test. This is the BHB level where you can expect a reduced appetite. It is often referred to simply as ‘ketosis’ or ‘nutritional ketosis’. The participants’ baseline ketogenic metabolism may have effected their responses to C8 MCT oil.

The BHB ketone boost lasted longer for the esters compared to the salts or C8 MCT oil. BHB ketone levels returned to baseline after 120 minutes following salt consumption. But they remained boosted 180 minutes following consumption of the ester.

Average Blood Glucose Responses

Figure 3. Average blood glucose levels following consumption of each exogenous ketone supplement

We saw that the ketone esters and ketone salts reduced blood glucose levels, whereas the C8 MCT oil did not. Similar to the BHB ketone boosts, this effect was most pronounced with the ketone esters. Blood glucose levels remained lower at 180 minutes following consumption of either ketone ester.