Supplement Label Index

Potassium Bicarbonate vs. Potassium Aspartate

Among 3,345 on-market potassium products with an identifiable primary form, 9.9% use Potassium Bicarbonate (332 products) and 9.3% use Potassium Aspartate (310).

Potassium BicarbonatePotassium Aspartate
Quality tierTier 1Tier 2
Potassium by weight39.1%22.8%
Share of market9.9%9.3%
On-market products332310
Median declared dose110 elemental mg
middle half: 95–200
50 elemental mg
middle half: 25–99
Most common brandsIsotonix, Nuun, Pure Essence Ionic-FizzDouglas Laboratories, Bluebonnet, Pure Encapsulations

Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).

Why Potassium Bicarbonate is tier 1

Used at doses shown to reduce urinary calcium excretion and bone-resorption markers in older adults, implying good systemic delivery (not a head-to-head absorption comparison).

Source: Sebastian A et al., PMID 18940881

Why Potassium Aspartate is tier 2

No dedicated comparative bioavailability study located; assumed acceptable given the label cross-check.

Source: uncertain -- needs review

Tiers summarize published comparative bioavailability or outcome evidence for each form (see methodology). This page describes the market; it is not a recommendation to take either form. Talk to a clinician about what's right for you.

Other potassium comparisons