Beta-hydroxybutyrate (BHB) is a naturally occurring compound your body produces, specifically a type of ketone body. It becomes especially prominent when carbohydrate intake is low, serving as an alternative energy source. This molecule is also available in dietary supplement form, offering a way to introduce ketones into the body externally.
Understanding Beta-Hydroxybutyrate
Beta-hydroxybutyrate is one of three primary ketone bodies, alongside acetoacetate and acetone, produced by the liver. Its structure allows efficient energy utilization throughout the body. The liver generates BHB when glucose, the body’s preferred fuel, is scarce, such as during fasting, prolonged exercise, or adherence to a very low-carbohydrate diet, like the ketogenic diet.
BHB functions as an alternative fuel source, providing energy to various tissues, including the brain and muscles. It is the most abundant ketone in the bloodstream, making up about 78% of the ketones present. When the body shifts from burning glucose to burning fat for fuel, BHB becomes a readily available energy molecule for cellular processes.
How BHB Supplements Work
Exogenous BHB supplements are external sources of beta-hydroxybutyrate, meaning they are ingested rather than produced internally. These supplements differ from the BHB your liver naturally makes, which is called endogenous BHB. Consuming exogenous BHB can quickly elevate blood ketone levels, mimicking ketosis without strict dietary adherence.
Common forms of BHB supplements include BHB salts and BHB esters. BHB salts bind BHB to minerals like sodium, potassium, calcium, or magnesium, making them more palatable and easier to incorporate into products. These salts can modestly increase circulating BHB levels, peaking around 0.5 to 1.0 mmol/L, though their effects are more transient.
In contrast, BHB esters involve BHB chemically bonded to an alcohol, such as 1,3-butanediol. Upon ingestion, these ester bonds are broken down, rapidly releasing free BHB into the bloodstream. This leads to a sharper and higher rise in blood ketone concentrations, potentially reaching 3–5 mmol/L within 30–60 minutes. While ketone esters are more potent in elevating blood ketone levels, they may have a less agreeable taste than ketone salts.
Potential Applications of BHB Supplements
Individuals may take BHB supplements to support energy levels and cognitive function. Exogenous ketones can provide an immediate energy source for the brain and muscles. This can be noticeable during the initial stages of a ketogenic diet, helping to mitigate “keto flu” symptoms like fatigue and mental fogginess.
BHB’s ability to cross the blood-brain barrier means it can provide accessible energy to brain tissues, potentially enhancing mental performance, focus, and clarity. Research suggests BHB may help improve cognitive functions, such as multitasking. It may also offer a more efficient energy source for the brain per unit of oxygen than glucose.
Beyond cognitive support, BHB supplements are explored for their potential to aid exercise performance and recovery. BHB can improve endurance and energy during physical activity. This occurs as the body preferentially uses ketones for fuel, sparing carbohydrate stores and promoting fat burning, potentially leading to increased stamina.
Another area of interest is appetite regulation. Studies indicate that exogenous ketone esters may help reduce hunger hormones and act as appetite suppressants. This effect could contribute to feelings of fullness and assist with managing food intake, although more research is needed to fully understand the mechanisms and impact on weight management.
Considerations Before Taking BHB Supplements
When considering BHB supplements, understanding dosage and potential side effects is important. Most exogenous BHB supplements contain between 11-16 grams of BHB per serving, a dose considered effective without causing major issues. Achieving nutritional ketosis, where blood BHB levels are between 0.6 and 3.0 mmol/L, is a common goal for those using these supplements.
Potential side effects, though mild and transient, can include gastrointestinal discomfort such as stomach upset, diarrhea, constipation, or stomach pain. These effects are more likely to occur with very high doses. Less frequent side effects include headache and loss of appetite.
Individuals with pre-existing health conditions, especially diabetes, should exercise caution. BHB can influence blood sugar levels and insulin sensitivity, requiring careful monitoring. Always consult a healthcare professional before starting any new supplement, particularly for those with underlying medical conditions or taking medications, to ensure safety and appropriateness.