ApoB (apolipoprotein B) is a protein found on every particle that can cause plaque, one per particle, so an ApoB blood test counts the number of those particles rather than the cholesterol they carry.
Also called: apolipoprotein B, apo B, apoB-100.
General information, not medical advice
Ranges and goals vary with your overall heart risk and between labs. Go through your own results with your doctor or another qualified health professional.
What it measures
Each LDL, VLDL and Lp(a) particle carries exactly one ApoB molecule, so the ApoB level is a direct count of potentially plaque-forming particles. LDL cholesterol measures how much cholesterol those particles hold. Usually the two agree. When they don't, for example an LDL at goal but a high ApoB, ApoB predicts risk more accurately.
That mismatch is most common with high triglycerides (150 mg/dL / 1.7 mmol/L or more), type 2 diabetes, heart disease and other cardiometabolic conditions. ApoB isn't on a standard lipid panel. It's standardised between labs and doesn't need fasting.
The 2026 ACC/AHA guideline says ApoB testing can be useful for people already on treatment, once their LDL and non-HDL goals are met, particularly with high triglycerides, diabetes or a very low LDL. It may also help some people not yet on treatment.
Numbers to know
The guideline doesn't give one normal range for ApoB, and your lab report will show its own. These are the figures it does use. US labs report ApoB in mg/dL; UK and European labs often use g/L (divide mg/dL by 100).
| ApoB | What the 2026 guideline says |
|---|---|
| 140 mg/dL (1.4 g/L) or more | Severe high cholesterol, alongside or instead of an LDL of 190 mg/dL (4.9 mmol/L) or more |
| Under 100 mg/dL (1.0 g/L) | Paired with an LDL goal of under 100 mg/dL for people with a low coronary calcium score (1 to 99) |
| Under 55 mg/dL (0.55 g/L) | May be a reasonable goal for people with heart disease and severe high cholesterol, once their LDL and non-HDL goals are met |
What raises and lowers it
- Raises it: the same things that raise LDL and triglycerides, including saturated fat, excess weight, insulin resistance and type 2 diabetes, and inherited lipid disorders.
- Lowers it: statins and other LDL-lowering medicines (ezetimibe, PCSK9 inhibitors), and diet changes that lower LDL.
Deeper reading
Related terms
- HDL cholesterol
- LDL cholesterol
- Lipoprotein(a)
- Non-HDL cholesterol
- PREVENT risk calculator
- Triglycerides
- VLDL cholesterol
- All glossary terms
Frequently asked questions
Is ApoB better than LDL cholesterol?
When the two disagree, ApoB predicts heart risk more accurately, because it counts the particles rather than the cholesterol in them. The 2026 ACC/AHA guideline still uses LDL and non-HDL as the main goals, and suggests ApoB mainly for people on treatment who have already reached them.
What is a good ApoB level?
The 2026 ACC/AHA guideline doesn't set one normal range. It pairs ApoB under 100 mg/dL (1.0 g/L) with an LDL goal of under 100 mg/dL in one group, and says a goal under 55 mg/dL may be reasonable for people with heart disease and severe high cholesterol. Check the reference range on your own lab report.
Do I need to fast for an ApoB test?
No. The 2026 guideline notes that ApoB measurement is standardised and unaffected by fasting.
Sources
- Blumenthal RS, Morris PB, et al. 2026 ACC/AHA Guideline on the Management of Dyslipidemia. J Am Coll Cardiol. 2026;87(19). Also in Circulation, doi:10.1161/CIR.0000000000001423.
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