Exogenous ketones are drinks or supplements that raise blood beta-hydroxybutyrate (BHB), a ketone, without fasting or a low-carb diet. They come as ketone esters or as ketone salts (BHB bound to sodium and potassium), and are taken for exercise performance and blood sugar.
Also known as: ketone esters, ketone salts, BHB salts, beta-hydroxybutyrate, ketone monoester.
A metabolic study gave ester or salt drinks that delivered about 12 g or 24 g of BHB (Stubbs 2017). These are study protocols, not a recommendation.
It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling.
What studies show: a 2022 meta-analysis of 43 trials (586 people) found a single dose raised blood BHB and lowered blood sugar (by about 0.5 mmol/L), more with esters than salts, with little evidence on longer use (Falkenhain 2022). A 2020 meta-analysis of 13 trials found no clear effect on exercise performance, from sprints to events of about 50 minutes (Valenzuela 2020). A 2024 meta-analysis found no change in blood pressure, with a possible rise in resting heart rate at higher doses (Marcotte-Chénard 2024).
In the metabolic study, the ester drink lowered blood pH slightly and the salt drink made urine alkaline; blood electrolytes stayed normal. Half the BHB in the salt drinks was the L form, which stayed in the blood for over 8 hours (Stubbs 2017).
We could not find a single published half-life. In a metabolic study, blood D-BHB peaked at about 2.8 mmol/L after an ester drink and 1.0 mmol/L after a salt drink and returned to baseline within 3 to 4 hours; a meal before the ester drink lowered the peak by a third (Stubbs 2017).
How Dose Track handles peptides · Reconstitution calculator · Half-life calculator