---
title: Large HDL Particle Test
type: biomarker
url: "https://www.test-well.com/biomarkers/large-hdl-particle"
also_known_as:
  - large hdl particle
  - large hdl p
  - large hdl-p
  - hdl large
category: Heart Health
units:
  - umol/L
  - "µmol/L"
  - nmol/L
reviewed_at: 2026-10-09
---

# Large HDL Particle

> Large HDL Particle is measured with a standard blood draw; no fasting is needed. TestWell offers panels that include Large HDL Particle, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.

Also known as: large hdl particle, large hdl p, large hdl-p, hdl large.

## Key facts

| Fact | Value |
| --- | --- |
| Units | umol/L / µmol/L / nmol/L |
| Sample | Blood |
| Fasting | Not required |
| Results | 1–3 business days |
| Labs | Quest or Labcorp |

## What does Large HDL Particle measure?

The count of large HDL particles — the HDL subclass most consistently associated with cardiovascular protection.

## What does a low Large HDL Particle mean?

Low large-HDL counts often accompany insulin resistance, high triglycerides and a Pattern B LDL profile.

## Common questions about Large HDL Particle

### Do I need a doctor's order to test my large hdl particle?

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 Large HDL Particle results?

Most Large HDL Particle 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.

### Where can I order a Large HDL Particle test?

TestWell offers panels that include Large HDL Particle alongside related markers. Browse our test catalog to find the panel that fits your goals.

### Do I need to fast before my Large HDL Particle test?

Fasting is not required for the Large HDL Particle test. You can have your blood drawn any time of day.

### Which lab will process my Large HDL Particle 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

- [Testing.com (AACC) — HDL Cholesterol Test](https://www.testing.com/tests/hdl-cholesterol/)

## 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 2026-10-09. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md

Canonical page: https://www.test-well.com/biomarkers/large-hdl-particle
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.