Potassium aspartate is a potassium salt of L-aspartic acid, an amino acid, with the chemical formula KO2CCH(NH2)CH2CO2H·H2O. It is used as a dietary supplement to treat low potassium levels (hypokalemia) and high blood ammonia (hyperammonemia), and is under investigation as an adjunctive treatment for hypertension. Potassium aspartate is also employed in cosmetics as a buffering agent and in research settings for electrophysiological studies.
Chemical properties Potassium aspartate is a white powder that is water-soluble. It consists of potassium cations (K⁺) bound to aspartate anion. The monohydrate form has a molecular weight of 171.19 g/mol. In supplements, each 450 mg capsule typically provides 99 mg of elemental potassium, equivalent to approximately 2.53 mEq. In research, Potassium aspartate is used in electrophysiological studies, such as in pipette solutions for voltage-clamp experiments, to maintain intracellular potassium levels and support ionic currents (e.g., Ca²⁺-activated K⁺ currents in gonadotropes).
Medical application Potassium aspartate is not approved for use as a chemical in its own right (but may be approved as a component in a product covered by a group standard) in the United States or European Union or New Zealand or Australia, for treating any medical condition, but is studied as an alternative to potassium chloride to treat high blood pressure (hypertension): potassium chloride reduces blood pressure, with a more pronounced effect in patients with hypertension—averaging a reduction of 8.2 mm Hg systolic and 4.5 mm Hg diastolic; yet, potassium aspartate may have a greater impact on lowering blood pressure at lower doses. While increasing intake of potassium-rich foods like bananas, grapefruit, dried beans, peas, broccoli, spinach, pumpkins, and squash is preferable, potassium aspartate is studied as a potential adjunctive treatment for hypertension.
Hypokalemia Potassium aspartate is used as a dietary supplement to treat or prevent hypokalemia (low blood potassium levels), which can cause muscle weakness, cramps, fatigue, and irregular heart rhythms. Hypokalemia is typically due to excessive potassium loss (e.g., via urine or intestines) rather than dietary deficiency, often triggered by diuretics, vomiting, or diarrhea. In cases of metabolic acidosis, Potassium aspartate may be preferred over potassium chloride due to its alkalinizing properties. Doses of 1.5 to 3 g (20–33 mEq) per day are recommended when dietary sources (e.g., bananas, spinach) are insufficient, with serum potassium levels monitored to avoid hyperkalemia.
Hypertension Potassium aspartate is under investigation as an alternative to potassium chloride for managing hypertension (high blood pressure). A meta-analysis of 19 studies found that potassium chloride reduces blood pressure by an average of 8.2 mm Hg systolic and 4.5 mm Hg diastolic in hypertensive patients, but a more recent study suggested Potassium aspartate may achieve similar effects at lower doses. The mechanism involves potassium's role in balancing sodium levels, relaxing vascular smooth muscle, and reducing blood vessel stiffness. However, clinical evidence for Potassium aspartate's superiority is limited.
Chronic Fatigue Historical studies from the 1960s explored oral Potassium aspartate combined with magnesium aspartate (1 g each) for chronic fatigue, reporting symptom relief in 75–91% of nearly 3,000 patients after 4–10 days of treatment, compared to 9–26% with placebo. These findings lack modern replication, and Potassium aspartate is not approved for fatigue treatment due to insufficient evidence.
Hyperammonemia Potassium aspartate is used in some settings to treat hyperammonemia (high blood ammonia), particularly in liver cirrhosis, by enhancing ammonia detoxification pathways. This application is typically intravenous and administered by healthcare professionals.
Other uses
Cosmetics Potassium aspartate is used in cosmetics and personal care products (e.g., baby products, bath products, hair care) as a buffering agent to stabilize pH and enhance product texture. The Cosmetic Ingredient Review (CIR) Expert Panel has deemed it safe for topical use, citing its low hazard profile and established safety as a food additive. The Food and Drug Administration (FDA) permits its use in over-the-counter products.
Research Applications In electrophysiological research, Potassium aspartate is a component of pipette solutions for patch-clamp studies, maintaining intracellular potassium concentrations. For example, a solution with 120 mM Potassium aspartate is used to study gonadotrope responses to gonadotropin-releasing hormone (GnRH), supporting oscillatory Ca²⁺-activated K⁺ currents.
See also Magnesium aspartate
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