--- title: LDL Particle Size Test type: biomarker url: "https://www.test-well.com/biomarkers/ldl-particle-size" also_known_as: - ldl particle size - ldl size category: Heart Health units: - nm order_price_usd: 70.99 order_item: Advanced Cholesterol Particle Test (NMR) order_url: "https://www.test-well.com/tests/nmr-lipoprofile" reviewed_at: 2026-09-08 --- # LDL Particle Size > LDL Particle Size is measured with a standard blood draw after an 8–12 hour fast. A typical reference range is 20.6 – 22.0 nm. At TestWell it's $70.99 all-in as Advanced Cholesterol Particle Test (NMR), results in 3–5 business days, drawn at Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis. Also known as: ldl particle size, ldl size. ## Key facts | Fact | Value | | --- | --- | | Units | nm | | Sample | Blood draw | | Fasting | 8–12 hours | | Results | 3–5 business days | | Price | $70.99 | | Labs | Labcorp | ## What does LDL Particle Size measure? The average diameter of your LDL particles. Larger is generally healthier. ## What is the normal range for LDL Particle Size? | Population | Reference range | | --- | --- | | age 18+ | 20.6 – 22.0 nm | Reference intervals differ slightly between labs; the range printed on your report is the one to interpret against. Ranges are usually set so 95% of healthy people fall inside them. ## What does a low LDL Particle Size mean? Small LDL particles (below about 20.5 nm — 'pattern B') are more atherogenic than large ones: they enter the artery wall more easily and oxidize faster. Small size is driven almost entirely by high triglycerides and insulin resistance; it is the lipid signature of metabolic syndrome and type 2 diabetes. Lowering triglycerides shifts particles larger within months. ### Common causes of low LDL Particle Size 1. Insulin resistance, prediabetes, type 2 diabetes, central obesity 2. High triglycerides, low HDL 3. Refined-carbohydrate diets, inactivity 4. Genetic pattern B phenotype 5. Hypothyroidism ### Symptoms that go with low LDL Particle Size - None ### What clinicians usually check next - Triglycerides, fasting insulin or A1c, ApoB (the particle count matters more than size for risk decisions) - Lifestyle changes aimed at triglycerides; retest in 3–6 months - Cardiovascular risk review with a clinician **Does LDL particle size matter if my ApoB is normal?** Less than people think — particle number (ApoB or LDL-P) carries most of the risk information. Small size mainly tells you insulin resistance is present, which is itself worth acting on. ## How do you get tested for LDL Particle Size? | Order | Type | Price | Includes | | --- | --- | --- | --- | | [Advanced Cholesterol Particle Test (NMR)](https://www.test-well.com/tests/nmr-lipoprofile) | Single test | $70.99 | This marker | ## Quest vs Labcorp vs BioReference | Lab | Available | Price | Notes | | --- | --- | --- | --- | | Quest Diagnostics | No | — | Not offered through Quest for this test. | | Labcorp | Yes | $70.99 | Choose Labcorp at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. | | BioReference (NY & NJ) | No | — | Not available in NY/NJ for this test. | ## Common questions about LDL Particle Size ### Do I need a doctor's order to test my ldl particle size? No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor. ### How long does it take to get LDL Particle Size results? Most LDL Particle Size results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal. ### How much does a LDL Particle Size test cost? Our Advanced Cholesterol Particle Test (NMR) starts at $70.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted. ### Do I need to fast before my LDL Particle Size test? Yes — for the most accurate result, fast for 8–12 hours before your blood draw. Water is fine; coffee, food, and supplements are not. Your prep instructions will be included with your order. ### Which lab will process my LDL Particle Size test? Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations. ## Sources - [Quest Diagnostics](https://testdirectory.questdiagnostics.com/test/test-detail/91716/cardio-iq-ion-mobility-lipoprotein-fractionation) - [Testing.com (AACC) — LDL-P Test: A LDL Particle Number](https://www.testing.com/tests/ldl-particle-testing/) ## Related biomarkers - [Apolipoprotein B](https://www.test-well.com/biomarkers/apolipoprotein-b) - [Lipoprotein(a)](https://www.test-well.com/biomarkers/lipoprotein-a) - [NT-proBNP](https://www.test-well.com/biomarkers/nt-probnp) - [Homocysteine](https://www.test-well.com/biomarkers/homocysteine) - [LDL Particle Number](https://www.test-well.com/biomarkers/ldl-particle-number) - [Small LDL Particle](https://www.test-well.com/biomarkers/small-ldl-particle) - [Reference range lookup tool](https://www.test-well.com/tools/reference-range-lookup) - [Lab unit converter](https://www.test-well.com/tools/lab-unit-converter) - [All biomarkers](https://www.test-well.com/biomarkers) --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-08. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/biomarkers/ldl-particle-size 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.