Magnesium levels: what's normal, high and low
A mineral involved in 300+ enzyme reactions, including muscle, nerve, and heart function.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Magnesium is measured with a standard blood draw; no fasting is needed. A typical reference range is 1.70 – 2.20 mg/dL. At TestWell it's $19.99 all-in as Magnesium, results in 2–4 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- mg/dL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 2–4 business days
- Price
- $19.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
Magnesium Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 1.70 – 2.20 mg/dL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your Magnesium result may mean
Usually reflects supplement excess or kidney impairment.
What a high Magnesium means: causes, symptoms, next steps →Common in alcohol use, diuretic use, GI losses, or poor diet. Can cause muscle cramps and arrhythmias.
What a low Magnesium means: causes, symptoms, next steps →Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
How do you get a Magnesium test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Magnesium is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Magnesium | This marker only | $19.99 |
| Fitness & Performance Panel | 8 tests | $119.99 |
| Sleep Health Panel | 8 tests | $129.99 |
| Vitamin & Mineral Deficiency Panel | 9 tests | $189.99 |
| Total Body Panel | 49 tests | $499.99 |
Quest vs. Labcorp for Magnesium: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $19.99 |
| Labcorp | Yes | $19.99 |
| BioReference (NY & NJ) | Yes | $20.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
Usually reflects supplement excess or kidney impairment. A single result above the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your magnesium?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $19.99.