Feeling fatigued, experiencing muscle cramps, or struggling with low energy? Magnesium is essential for muscle function, nerve signalling, and heart health, but low levels can often go unnoticed. This test measures your serum magnesium levels, helping to identify deficiencies that could be affecting your energy, mood, or overall well-being.




Magnesium (serum) Blood Test
- Results estimated in 3 working days
- Convenient testing options
- Bespoke doctor’s report
- Free delivery
Measures serum magnesium to assess magnesium levels in the blood and detect deficiencies or imbalances. For a more comprehensive test including magnesium, upgrade to our Advanced Well Man Blood Test or Advanced Well Woman Blood Test.
How do you want to take your sample?
Please choose one option below-
Collect your own finger-prick blood sample at homeFreeWe’ll send you everything you need to collect your blood sample from your finger at home.
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Book a venous draw at a clinic Venous+£35Visit one of our national clinic partners for a nurse to take your venous blood sample from a vein in your arm. We’ll email you instructions on how to book after we’ve processed your order.
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Book a venous draw at home with a nurse Venous+£59Book a home nurse appointment for a nurse to take your venous blood sample from a vein in your arm.
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Self-arrange a professional sample collection VenousFreeMake an appointment at a phlebotomy clinic to have your venous blood sample taken. You will be responsible for arranging your appointment and any additional fees.
18+ Only. T&Cs apply.
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Go beyond the numbers
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How it works
You have the flexibility to choose what works best for you. Enjoy the comfort of having a friendly nurse visit your home for a quick blood draw, opt for a convenient visit to one of our nationwide partner clinics, or self-arrange a draw at a location that suits you.
Take control of your health with Medichecks – order your blood test today!

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What's in the test?
Minerals
Magnesium - serum
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How to prepare for your test
Test limitations
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FAQs
What can I learn from a magnesium test?
Our test can tell you if your magnesium levels are normal and whether you need to eat more magnesium-rich foods. Magnesium is in fibre-rich foods such as green leafy vegetables, avocados, bananas, wholemeal bread, brown rice, fish, and meat. Too much magnesium is often caused by over-supplementation or taking too many antacids or milk of magnesia.
What are the symptoms of too much magnesium?
Symptoms of excess magnesium include breathing problems, skin and eye irritation, flu-like symptoms, and an upset stomach. Low magnesium can cause muscle twitching and cramps, fatigue, osteoporosis, an irregular heartbeat, and high blood pressure. Low magnesium is associated with heart disease, atherosclerosis, stroke, and diabetes.
What is magnesium?
Magnesium is a mineral that supports proper muscle, nerve, and enzyme function. It helps your body make and use energy and is needed to move other electrolytes (potassium and sodium) into and out of cells. Most magnesium is found in your bones and inside your cells. Only a tiny amount is usually present in your blood.