Hospital Lab
$95
cash pay
Other Labs
$45
+ lab fees
TestWell
$29.99
+ $6 lab fee
Magnesium, RBC measures the magnesium held inside your red blood cells rather than in the serum. Because most of the body's magnesium is stored intracellularly, RBC magnesium is considered a more sensitive indicator of long-term magnesium status and can reveal a deficiency even when a standard serum magnesium reads normal. It's often ordered by practitioners investigating fatigue, muscle cramps, poor sleep, anxiety, migraines, or irregular heartbeat when a serum test wasn't conclusive.
Sample Type
Blood draw
Fasting
Not required
Results In
5–9 business days
Performed At
Quest or Labcorp
1 biomarker tested
Your Magnesium, RBC results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 5–9 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you.
Your Magnesium, RBC results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 5–9 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you.
No fasting required.
No fasting required.
TestWell Price
$29.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Frequently ordered together
Customers who ordered Magnesium, RBC also added these for a more complete health picture.
Not sure where to start?
Magnesium, RBC
$29.99