Molecular Classification
Other (Metabolite/Small molecule), Organic acids and derivatives (specifically beta hydroxy acids and derivatives), Ketone body
Other Names
β-Hydroxybutyric acid, 3-Hydroxybutyric acid, 3-Hydroxybutanoic acid, BHB, (S)-3-Hydroxybutyric acid, D-beta-hydroxybutyrate
Disease Roles
Metabolic diseases (e.g., diabetes mellitus—marker for diabetic ketoacidosis)Liver diseases (potential therapeutic role in liver protection and repair)Neurological disorders (alternative energy source for brain during hypoglycemia/fasting; potential neuroprotective effects)

Beta-hydroxybutyrate Overview

Beta-hydroxybutyrate (BHB) is the most abundant ketone body produced primarily in the liver from fatty acids during periods of low carbohydrate intake, prolonged exercise, starvation, or untreated diabetes mellitus. It serves both as an alternative energy substrate, especially important for the brain when glucose availability is limited, and acts as a signaling molecule, influencing cellular processes through direct inhibition of class I histone deacetylases and modulation of gene expression related to metabolism and stress responses. Elevated blood levels are characteristic markers for metabolic states like ketosis but also serve diagnostically in conditions such as diabetic ketoacidosis. While exogenously administered BHB has been explored therapeutically—for example via supplements—it does not represent a conventional drug target but rather functions within broader metabolic networks.

Mechanism of Action

Not applicable in the traditional sense since BHB is not targeted by drugs but can act: - As an HDAC inhibitor when present at high concentrations—modulating gene expression epigenetically. - As an alternative fuel source for tissues during low glucose availability by entering mitochondrial metabolism via conversion to acetyl-CoA.

Biological Functions

Energy substrate during fasting or low glucose states
Signaling molecule affecting gene expression and metabolism
Inhibits class I histone deacetylases (HDACs)
Modulates lipid/protein metabolism, neuronal function, metabolic rate
Alters biosynthesis of neurotransmitters such as GABA in astrocytes

Disease Associations

Metabolic diseases (e.g., diabetes mellitus—marker for diabetic ketoacidosis)
Liver diseases (potential therapeutic role in liver protection and repair)
Neurological disorders (alternative energy source for brain during hypoglycemia/fasting; potential neuroprotective effects)

Safety Considerations

  • High levels of BHB can indicate pathological states such as: Diabetic ketoacidosis—a life-threatening complication if uncontrolled. Alcoholic ketoacidosis.
  • Excessive exogenous supplementation may cause electrolyte imbalances or gastrointestinal side effects at high doses.

Interacting Drugs

Exogenous BHB supplements (used therapeutically to induce ketosis or provide alternative energy sources in clinical trials for various conditions)

Associated Biomarkers

Biomarker
Diabetic ketoacidosis diagnosis/monitoring in diabetes patients
Monitoring ketosis status during ketogenic diets or fasting