Thus, ketones found in supplements are exogenous ketones.
These supplements contain only the beta-hydroxybutyrate ketone. The other primary ketone body, acetoacetate, is not chemically stable as a supplement.
There are two main forms of ketone supplements:
- Ketone salts: These are ketones bound to a salt, typically sodium, potassium, calcium or magnesium. They’re most often found in powder form and mixed with liquid.
- Ketone esters: These are ketones linked to another compound called an ester and packaged in liquid form. Ketone esters are used primarily in research and aren’t as readily available for purchase as ketone salts (6Trusted Source).
Both forms of ketone supplements have been shown to increase blood ketone levels, mimicking what happens in ketosis when you follow a ketogenic diet (7Trusted Source, 8Trusted Source, 9Trusted Source, 10Trusted Source).
In one study, supplementing with approximately 12 grams (12,000 mg) of ketone salts increased participants’ blood ketone levels by over 300% (8Trusted Source).
For reference, most available ketone supplements contain 8–12 grams of ketones per serving.
This elevation in blood ketone levels following supplementation is beneficial for people who want to transition into ketosis without necessarily having to follow the diet (11Trusted Source).
That said, supplementing with ketones is thought to have many of the same health benefits as a ketogenic diet, including weight loss.
People also take ketone supplements along with a ketogenic diet, especially when first beginning the diet.
This reduces the time it takes to reach ketosis and lessens the unpleasant effects that may come from transitioning from a standard, higher-carb diet to a ketogenic one.
The symptoms that often accompany the transition to a ketogenic diet, more commonly known as the “keto flu,” include constipation, headache, bad breath, muscle cramps and diarrhea.
Ketone supplements have been shown to decrease appetite, which may help you lose weight by eating less.
In one study in 15 people of normal weight, those drinking a beverage containing ketone esters experienced 50% less hunger after an overnight fast than those drinking a sugary beverage (13Trusted Source).
This appetite-suppressing effect was attributed to lower levels of the hunger hormone ghrelin between two and four hours after drinking the ketone ester drink (13Trusted Source).
However, ketone supplements may not affect appetite as much in people who have had a meal beforehand.
Studies have observed higher blood ketone levels in those who didn’t eat a meal before taking a ketone supplement compared to those who did (14Trusted Source, 15Trusted Source, 16).
And since it’s the elevated ketones that are associated with reduced appetite and lower ghrelin levels, ketone supplements may only be beneficial during a fast, such as upon rising in the morning, rather than after a meal that contains carbs (13Trusted Source).
In other words, taking a ketone supplement after a carb-containing meal will still raise blood ketone levels but not as high as if you fasted, suggesting that your body is using fewer ketones as fuel since there is more available glucose from the carbs.
