Short answer
No. ApoB counts all the cholesterol-carrying particles that can clog arteries, because each one carries a single ApoB protein. Lp(a) is one specific type of those particles, set more than 90% by your genes. ApoB can change with diet and treatment; Lp(a) mostly can't. Guidelines say every adult should have Lp(a) measured at least once.
What ApoB measures
A 2019 JAMA Cardiology review explains that VLDL, LDL, chylomicron and Lp(a) particles each contain one molecule of ApoB. So an ApoB test is effectively a particle count of the cholesterol carriers that can enter artery walls. The 2018 AHA/ACC cholesterol guideline lists ApoB of 130 mg/dL or more as a risk-enhancing factor, which corresponds roughly to LDL cholesterol of 160 mg/dL or more.
What Lp(a) measures
Lp(a) is an LDL-like particle that carries ApoB plus an extra protein. The European Atherosclerosis Society's 2022 consensus says its level is more than 90% determined by genetics, which is why one test usually tells you your lifelong level. The consensus and the US National Lipid Association's 2024 update both say to measure it at least once in every adult. The NLA puts low risk below 75 nmol/L (30 mg/dL) and high risk at 125 nmol/L (50 mg/dL) or above, and estimates about 1 in 5 people have elevated levels.
Why you might want both
Because Lp(a) particles carry ApoB, they are included in your ApoB number, but they are a small share of the total for most people. A normal ApoB can sit alongside a high Lp(a), and that is the result an ApoB test alone would miss. That is why many people ask for both tests once, then track ApoB over time. Your doctor can interpret both alongside the rest of your risk factors. Educational content, not medical advice.
Related questions
Do I need to repeat the Lp(a) test?
Usually not. Since the level is mostly genetic, guidelines say measure at least once; your doctor may repeat it in specific cases.
Is ApoB the same as LDL?
No. LDL cholesterol measures how much cholesterol is carried; ApoB counts the particles carrying it.
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Sources
Published 2026-10-04 · Last checked 2026-10-04
Educational content, not medical advice. Made for the United States.