Potassium
Potassium is the main intracellular cation and is essential for heart rhythm, muscle contraction, and nerve conduction. Low potassium (hypokalemia) causes weakness, cramping, and arrhythmias and is often from diuretics, vomiting, or diarrhea; high potassium (hyperkalemia) can cause dangerous arrhythmias and usually reflects kidney dysfunction or potassium-sparing drugs.
Units: mEq/L; some labs report mmol/L (same number in both units). Check the units on your report before comparing to any range here.
Optimal range: who says what
Institutions, researchers and practitioners draw the line in different places. Each position is listed with who holds it and, where a document states it, a link. How we verify ranges.
- Institution or study4.0-4.5 mEq/LCardiac outcome cohorts favor mid-range potassium
- Lab reference interval3.5-5.0 mEq/LWhat a lab report flags against. A lab interval is not an optimal target.
20 of 21 itemized panels
Electrolytes & Minerals
Why Potassium matters
Essential for heart rhythm and muscle contraction. Abnormal levels can cause fatal arrhythmias. Affected by kidney function and medications.
Which Providers Test Potassium?
Cheapest: Oura Health Panels at $99/year. Most comprehensive: Function Health, 160+ biomarkers for $365/year.
20 panels that include it, cheapest first
| Provider | Annual Cost | Total Biomarkers | $/Biomarker |
|---|---|---|---|
| $99 | 50 | $1.98 | |
| $190 | 100+ | $1.90 | |
| $250 | 65 | $3.85 | |
| $297 | 100+ | $2.97 | |
 Labcorp OnDemand | $338 | 50+ | $6.76 |
 Superpower | $349 | 100+ | $3.49 |
| $349 | 75+ | $4.65 | |
 WHOOP Advanced Labs | $349 | 65 | $5.37 |
 Function Health | $365 | 160+ | $2.28 |
| $365 | 100+ | $3.65 | |
| $375 | 108 | $3.47 | |
| $449 | 83 | $5.41 | |
| $495 | 80+ | $6.19 | |
| $499 | 100+ | $4.99 | |
| $700 | 138 | $5.07 | |
| $829 | 54 | $15.35 | |
| $895 | 100+ | $8.95 | |
| $1188 | 70+ | $16.97 | |
| $1198 | 40+ | $29.95 | |
| $1950 | 130+ | $15.00 |
$/Biomarker is annual cost divided by the panel's advertised biomarker count, not the price of this one test. We track 23 blood test providers (32 plans); 21 of those plans are itemized marker by marker. Compare all of them.
1 itemized panel does not include Potassium
11 providers not itemized in our matrix
We have not itemized these marker by marker (some sell tests one at a time), so this page cannot say whether they offer Potassium. Check with them directly.
Life Extension Standard · Quest Health · Ultrahuman Blood Vision · Lifeforce · Hundred Health · Personalabs · Walk-In Lab · HealthLabs · WHOOP Specialized Panels · Marek Health Essential · Vitality Blueprint Upload
Experts discussing Potassium
Podcast episodes where clinicians and researchers cover this marker in depth. Curated by hand; an episode is listed only when the marker is a substantial topic, not a passing mention.
- Using Salt to Optimize Mental & Physical PerformanceDisclosure: Huberman Lab has been sponsored by Function Health, which appears in our blood-test comparisons.
Frequently Asked Questions
What is the optimal range for Potassium?
Published position: 4.0-4.5 mEq/L (Cardiac outcome cohorts favor mid-range potassium). Lab reference interval: 3.5-5.0 mEq/L. That is what a lab report flags against, not an optimal target.
Which blood test providers include Potassium?
20 of the 21 blood testing panels we itemize marker by marker include Potassium in their panels. This biomarker is widely available across major providers.
Related: YouBoost rates lifestyle and supplement interventions by evidence.
Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed Aug 26, 2026 · First published Sep 30, 2025