The short answer
LDL particle number, or LDL-P, counts the LDL particles in your blood rather than the cholesterol they carry. When the two disagree, your risk tends to follow the count.1,2 Labcorp calls under 1,000 nmol/L low.5
- A good result
- Under 1,000 nmol/L, which Labcorp calls low.5 That’s a lab category, not a guideline target. Guidelines set targets for LDL cholesterol and ApoB instead.3,4
- If yours is high
- Lowering LDL cholesterol, usually with a statin, comes first. If your LDL is already under control, high triglycerides or insulin resistance are the likely cause.2
Check your result
Type the number from your report. It stays on this page.
- Low Under 1,000
- Moderate 1,000 to 1,299
- Borderline high 1,300 to 1,599
- High 1,600 to 2,000
- Very high 2,001 or more
Enter your result to see what it means and what to do next.
Got a result from another lab? Ask Picardo about it. The app explains your results, and a physician can follow up.
Categories from Labcorp, not guideline targets.5 Other labs’ methods give different numbers, so these only fit a Labcorp NMR result.2 The bar isn’t to scale.
Low: relatively few LDL particles
You have relatively few LDL particles. Labcorp calls this low.5 If you’re on cholesterol treatment, it means the particle count has come down, not just the cholesterol.1
Nothing to worry about.
- 1 Keep doing what you’re doing.
- 2 If you’ve never checked Lp(a), do it once. It’s an inherited risk that this test doesn’t report.
Moderate: whether it’s low enough depends on your risk
Labcorp calls this moderate.5 Whether that’s low enough depends on your overall heart risk. There’s no guideline target for LDL-P, so your goal for LDL cholesterol or ApoB is the better guide.3,4
Not a worry on its own.
- 1 Compare it with your LDL cholesterol on the same report. If LDL-P looks higher than your LDL suggests, check your triglycerides and blood sugar.1,2
- 2 Check ApoB, which has targets for each level of heart risk.4
Borderline high: worth a closer look
Labcorp calls this borderline high.5 The more LDL particles you have, the more can lodge in your artery walls and build plaque over the years.1
Worth acting on over the next few months. It isn’t urgent.
- 1 See a clinician to estimate your overall risk. If you need treatment, lowering LDL cholesterol, usually with a statin, comes first.2
- 2 If your LDL cholesterol is already in range, look at triglycerides, weight and blood sugar. They’re the usual reason the count stays high.2
- 3 Recheck 4 to 12 weeks after any change in treatment.2
High: time to talk about treatment
Labcorp calls this high.5 Most often it goes with high LDL cholesterol. When LDL looks normal, high triglycerides and insulin resistance are the usual reason.1,2
Worth acting on in the next month or two. It isn’t urgent.
- 1 See a clinician about treatment. A statin is usually the first step.2
- 2 Check ApoB and Lp(a) if you haven’t. ApoB has guideline targets, and Lp(a) is a separate, inherited risk.4
- 3 Recheck 4 to 12 weeks after any change.2
Very high: see a clinician about treatment
Labcorp calls this very high.5 Your blood is carrying a large number of LDL particles, the kind that build plaque over years.1
Book an appointment in the next few weeks. It isn’t an emergency.
- 1 See a clinician about treatment. Lowering LDL with a statin comes first, and other medicines can be added if that isn’t enough.2
- 2 Look at the LDL cholesterol on the same report. If it’s 190 mg/dL or more, that’s severe high cholesterol, which can be inherited.2
- 3 Check ApoB and Lp(a).
What is a normal LDL particle number?
Labcorp sorts LDL-P into five groups. They’re lab categories, not treatment targets: guidelines set targets for LDL cholesterol and ApoB, but not for LDL-P.3,4,5 Results from different labs’ methods aren’t interchangeable, so compare like with like:2
Low: relatively few LDL particles
You have relatively few LDL particles. Labcorp calls this low.5 If you’re on cholesterol treatment, it means the particle count has come down, not just the cholesterol.1
Nothing to worry about.
- 1 Keep doing what you’re doing.
- 2 If you’ve never checked Lp(a), do it once. It’s an inherited risk that this test doesn’t report.
Moderate: whether it’s low enough depends on your risk
Labcorp calls this moderate.5 Whether that’s low enough depends on your overall heart risk. There’s no guideline target for LDL-P, so your goal for LDL cholesterol or ApoB is the better guide.3,4
Not a worry on its own.
Borderline high: worth a closer look
Labcorp calls this borderline high.5 The more LDL particles you have, the more can lodge in your artery walls and build plaque over the years.1
Worth acting on over the next few months. It isn’t urgent.
- 1 See a clinician to estimate your overall risk. If you need treatment, lowering LDL cholesterol, usually with a statin, comes first.2
- 2 If your LDL cholesterol is already in range, look at triglycerides, weight and blood sugar. They’re the usual reason the count stays high.2
- 3 Recheck 4 to 12 weeks after any change in treatment.2
High: time to talk about treatment
Labcorp calls this high.5 Most often it goes with high LDL cholesterol. When LDL looks normal, high triglycerides and insulin resistance are the usual reason.1,2
Worth acting on in the next month or two. It isn’t urgent.
What is LDL particle number?
Picture two roads carrying the same number of people. On one they ride in buses, on the other in small cars. The second road has far more vehicles, and vehicles are what cause jams. LDL cholesterol counts the people; LDL-P counts the vehicles.
LDL particles carry cholesterol through your blood. How much each one carries varies more than twofold from person to person, so the same LDL cholesterol can mean very different numbers of particles.1 LDL-P is that number, in nanomoles per liter (nmol/L).
Labcorp measures it with NMR spectroscopy, the technology behind MRI scanners. It reads the signal from the fat inside the particles, which differs by particle size, and works out how many particles of each size there are.1
How is LDL particle number different from ApoB?
Both count particles rather than cholesterol. ApoB counts every particle that can build plaque, including LDL, VLDL and Lp(a), because each carries one ApoB.3 LDL-P counts only LDL particles, which make up most of that total, and uses a different method.4
Guidelines prefer ApoB. European guidelines call ApoB an accurate count of these particles, and note that ApoB tests are standardized and inexpensive.4 US guidelines don’t use advanced lipoprotein tests, NMR included, to estimate heart risk or decide whether to start treatment. They say most of their numbers add little beyond a standard cholesterol test plus ApoB or Lp(a), that the methods lack standardization, and that they’re most useful when the result could change the treatment plan.3 The National Lipid Association says LDL-P can help guide treatment in some people, but that different LDL-P methods give results that can’t be compared.2
| ApoB | LDL particle number | |
|---|---|---|
| What it counts | Every particle that can build plaque | LDL particles only |
| How it’s measured | A standard blood protein test | NMR spectroscopy |
| Standardized across labs | Yes | No |
| Guideline targets | Yes | No |
| Fasting | Not needed | 8 to 12 hours |
From European and US guidelines, the National Lipid Association and Labcorp.2,3,4,6
Why can LDL particle number be high when LDL cholesterol is normal?
Your particles may be small and carry less cholesterol each. That’s most common with high triglycerides, low HDL, insulin resistance, diabetes or extra weight.1 Statins also lower LDL cholesterol more than they lower the count, so on treatment, LDL-P can stay higher than your LDL suggests.1
In MESA, a US study of 5,598 adults, people whose LDL-P and LDL cholesterol disagreed had a risk of heart disease and stroke that followed their LDL-P, not their LDL cholesterol.1 But in other large studies, LDL-P didn’t predict a first heart attack or stroke any better than a standard cholesterol test.2 It’s also unclear whether the extra risk comes from the particles themselves or from the high triglycerides and insulin resistance that tend to come with them.1,2
What do small LDL particles and LDL size mean?
Your NMR report also lists small LDL-P, the number of small LDL particles, and LDL size, the average size of your particles. Lots of small particles usually go with high triglycerides and insulin resistance.1,2
They add less than the total count. The National Lipid Association says LDL size adds little to predicting heart disease, and in MESA, small LDL-P wasn’t linked to a higher risk of heart disease.2 Treat the total LDL-P as the number that matters, and read a high small LDL-P as a prompt to check your triglycerides and blood sugar.
How to lower LDL particle number
- Statins
The first step when LDL-P is high. They lower the count, though usually by less than they lower LDL cholesterol.1,2
- How much it helps
- A lot
- How sure we are
- Very sure
- Adding ezetimibe or a PCSK9 inhibitor
Lower the count further on top of a statin. Trials haven’t tested whether aiming at LDL-P itself prevents more heart attacks.2
- How much it helps
- A lot
- How sure we are
- Fairly sure
- Treating high triglycerides and insulin resistance
If your LDL cholesterol is already in range, these are the likely reason LDL-P stays high. Losing extra weight and being more active are the place to start.2
- How much it helps
- Some
- How sure we are
- Early evidence
Clinicians usually recheck 4 to 12 weeks after a change.2 Treatment goals are set for LDL and non-HDL cholesterol, and sometimes ApoB, rather than LDL-P.3
Who should get an LDL particle number test?
It adds the most if any of these apply to you:2
- You have high triglycerides, insulin resistance, prediabetes or diabetes.
- You or a close relative has had heart disease.
- You’re on cholesterol treatment and want to see whether the particles, not just the cholesterol, have come down.
If your triglycerides and HDL are normal, it usually tells the same story as a standard cholesterol test.2 US guidelines don’t use it to estimate heart risk or decide whether to start treatment, and see it as most useful when the result could change the plan.3 Guidelines favor ApoB as the main particle count, so read the two together.3,4
How to get an LDL particle number test, and what it costs
It comes from the NMR LipoProfile, which costs $37.00 through Picardo. The Heart Health panel adds 16 more tests from the same visit for $150.90.
Heart Health panel
The panel includes this test and adds ApoB, the particle count guidelines prefer, and Lp(a), which this test doesn’t show. It also has hs-CRP, HbA1c, insulin, and kidney, liver and thyroid tests. See what’s in it
NMR LipoProfile
The test this number comes from.
- Results in 2 to 3 days, in the app
- Physician follow-up if you want one
- Free Labcorp draw, or $75 at home
- No other fees. HSA and FSA eligible.
It’s also part of the Base Core Annual – Men and Base Core Annual – Women panels, if you want a wider checkup.
Already have a result? Ask Picardo about itQuestions people ask
Do I need to fast for an LDL-P test?
Yes. Labcorp asks you to fast for 8 to 12 hours before the NMR LipoProfile.6 If you’re having it as part of a panel, follow the panel’s instructions, which may ask for longer.
What is the NMR LipoProfile?
It’s the Labcorp test that reports LDL-P. Alongside it, you get a standard cholesterol panel, small LDL-P, LDL size, HDL and VLDL particle measures and an insulin resistance score.6
Why is my LDL-P different at another lab?
Labs count LDL particles with different methods, such as NMR or ion mobility, and their results aren’t interchangeable.2 To follow your number over time, use the same lab and the same test.
Is LDL-P part of a standard cholesterol test?
No. A standard test measures cholesterol, not particles. LDL-P needs an NMR test, which reports the standard numbers too.6
Often checked alongside
Test details
Sources
- 1 Otvos JD, Mora S, Shalaurova I, Greenland P, Mackey RH, Goff DC Jr. Clinical implications of discordance between low-density lipoprotein cholesterol and particle number. J Clin Lipidol. 2011;5(2):105–113. doi.org/10.1016/j.jacl.2011.02.001
- 2 Wilson PWF, Jacobson TA, Martin SS, et al. Lipid measurements in the management of cardiovascular diseases: practical recommendations. A scientific statement from the National Lipid Association writing group. J Clin Lipidol. 2021;15(5):629–648. doi.org/10.1016/j.jacl.2021.09.046
- 3 Blumenthal RS, Morris PB, Gaudino M, et al. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of dyslipidemia: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2026;153(17):e1154–e1276. doi.org/10.1161/CIR.0000000000001423
- 4 Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Eur Heart J. 2020;41(1):111–188. doi.org/10.1093/eurheartj/ehz455
- 5 Labcorp. LDL-P, test 123828. Labcorp test menu. Accessed October 28, 2026. www.labcorp.com/tests/123828/ldl-p
- 6 Labcorp. NMR LipoProfile with lipids and insulin resistance markers (with graph), test 123638. Labcorp test menu. Accessed October 28, 2026. www.labcorp.com/tests/123638/nmr-lipoprofile-with-lipids-and-insulin-resistance-markers-with-graph
Updated 28 Oct 2026.
This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.