--- title: Magnesium Test type: test id: magnesium url: "https://www.test-well.com/tests/magnesium" price_usd: 19.99 lab_fee_usd: 6 all_in_usd: 25.99 cpt: 83735 category: Vitamins & Nutrients sample: Blood draw fasting_required: false results_in: "2–4 business days" labs: - Quest - Labcorp - BioReference orderable: true reviewed_at: 2026-09-14 order_url: "https://www.test-well.com/cart?add=magnesium&utm_source=ai_agent&utm_medium=markdown" --- # Magnesium Test > Essential mineral for muscles, nerves, and sleep — up to 50% of Americans don't get enough, measured from a standard blood draw. At TestWell it costs $19.99 plus a $6 lab fee, needs no fasting, and results post in 2–4 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest or Labcorp. ## Key facts | Fact | Value | | --- | --- | | Price | $19.99 + $6 lab processing fee per order ($25.99 all-in for this test alone) | | CPT code | 83735 | | Sample | Blood draw | | Fasting | Not required | | Results | 2–4 business days | | Labs | Quest Diagnostics, Labcorp, BioReference (NY & NJ) | | Biomarkers measured | 1 | | Physician authorization | Included — no doctor's visit, referral or insurance needed | | Payment | Card, HSA or FSA; cash-pay only (no insurance billing) | ## What does the Magnesium test tell you? Essential mineral for muscles, nerves, and sleep — up to 50% of Americans don't get enough. Magnesium is involved in over 300 enzymatic reactions in the body, including muscle and nerve function, blood sugar regulation, and blood pressure control. Despite its importance, an estimated 50% of Americans don't meet the recommended daily intake. Deficiency can cause muscle cramps, insomnia, anxiety, headaches, and irregular heartbeat. **Clinical use:** Measures serum magnesium — a cofactor in 300+ enzymatic reactions including energy production, muscle contraction, sleep regulation, and blood-sugar control. ## Who should order it? Anyone with muscle cramps, restless legs, insomnia, palpitations, migraine, or on medications that deplete magnesium (PPIs, diuretics, metformin). Increasingly ordered alongside Vitamin D for general wellness. ## Biomarkers measured - [Magnesium](https://www.test-well.com/biomarkers/magnesium) ## Price by lab | Lab | Test price | All-in (with $6 fee) | Notes | | --- | --- | --- | --- | | Quest Diagnostics | $19.99 | $25.99 | Choose at checkout; walk-in patient service centers nationwide (not NY/NJ) | | Labcorp | $19.99 | $25.99 | Choose at checkout; walk-in patient service centers nationwide (not NY/NJ) | | BioReference (NY & NJ) | $20.99 | $26.99 | New York and New Jersey orders route here automatically | Rhode Island is not served. Prices are identical online and in the lab; no draw fee or physician fee is added. ## How much does a Magnesium test cost? A Magnesium test costs $19.99 at TestWell — $25.99 all-in when ordered alone, because the $6 lab processing fee is charged once per order, with no draw fee or physician fee added. Ordered directly from the labs' own consumer sites, the same test lists at $39.00 at Quest Health and $39.00 at Labcorp OnDemand (list prices checked Sep 12, 2026). Hospital outpatient labs typically bill around $80.00 self-pay for the same test, and often more. With insurance, what you pay depends on your deductible and your plan's negotiated rate; TestWell's price is fixed before the draw and is HSA/FSA-eligible. | Where you order | Price | One test, all-in | Notes | | --- | --- | --- | --- | | TestWell (drawn at Quest or Labcorp) | $19.99 | $25.99 | Includes the one $6 lab processing fee, charged once per order | | Quest Health (Quest Diagnostics' own site) | $39.00 | $39.00 | [list price checked 2026-09-12](https://www.questhealth.com/product/magnesium-test/622M.html) | | Labcorp OnDemand (Labcorp's own site) | $39.00 | $39.00 | [list price checked 2026-09-12](https://www.ondemand.labcorp.com/lab-tests/magnesium-test) | | Hospital outpatient lab, self-pay (typical) | $80.00 | $80.00 | Reference figure; hospital charges vary widely by facility and are often higher | Lab test codes: Quest test code 622 · Labcorp test no. 001537 · BioReference code 0120-6. ## How do you prepare? No fasting required. ## Related conditions - Hypomagnesemia (E83.42) - [Type 2 diabetes](https://www.test-well.com/conditions/diabetes-screening) (E11.9) - [Insomnia](https://www.test-well.com/conditions/insomnia) (G47.00) - Migraine (G43.909) ## Common questions about the Magnesium test ### Serum vs RBC magnesium — which test should I order? Serum magnesium is the standard and what most clinicians order. Only ~1% of body magnesium is in serum, so it can miss intracellular deficiency — but RBC magnesium isn't reliably validated outside research settings. Serum is the right call for routine testing. ### How much does a magnesium test cost without insurance? TestWell charges $19.99 — vs $29 at Quest Direct and $50-$120 at hospital outpatient labs. ### Do I need to fast for a magnesium test? No fasting required. Avoid magnesium supplements for 24 hours before the draw for an accurate baseline. ### What's a normal magnesium level? Reference range: 1.7-2.2 mg/dL. Functional optimal: 2.0-2.2 mg/dL. <1.7 is overt deficiency; <2.0 is subclinical and often missed. ### What's the CPT code for a magnesium test? 83735 (Magnesium, serum). HSA/FSA eligible. ## How to order 1. Add to cart: https://www.test-well.com/cart?add=magnesium&utm_source=ai_agent&utm_medium=markdown 2. Create an account or sign in, confirm your state and preferred lab, pay by card, HSA or FSA. 3. A licensed physician authorizes the order (usually within minutes); the requisition arrives by email. 4. Walk into any Quest Diagnostics, Labcorp, BioReference (NY & NJ) patient service center — no appointment needed at most sites. 5. Results post to your TestWell portal in 2–4 business days with reference ranges and flags. ## Related - [Blood Tests for Athletes](https://www.test-well.com/guides/blood-tests-for-athletes) - [Fitness & Performance Panel](https://www.test-well.com/tests/fitness-performance-panel) — 8 tests · $119.99 - [Sleep Health Panel](https://www.test-well.com/tests/sleep-health-panel) — 8 tests · $129.99 - [Vitamin & Mineral Deficiency Panel](https://www.test-well.com/tests/vitamin-mineral-panel) — 9 tests · $189.99 - [Biotin (Vitamin B7)](https://www.test-well.com/tests/biotin) — $259.99 - [Calcium](https://www.test-well.com/tests/calcium) — $26.99 - [Copper](https://www.test-well.com/tests/copper) — $31.99 - [CoQ10 (Coenzyme Q10)](https://www.test-well.com/tests/coq10-coenzyme-q10) — $74.99 - [Folate (Vitamin B9)](https://www.test-well.com/tests/folate) — $32.99 - [All Vitamins & Nutrients tests](https://www.test-well.com/tests/category/vitamins-nutrients) - [Full test directory](https://www.test-well.com/tests/directory) --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-14. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/tests/magnesium Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.