ApoB (Apolipoprotein B) Blood Test
ApoB counts the actual number of artery-clogging particles in your blood — many researchers consider it a sharper cardiovascular risk marker than LDL cholesterol.
What ApoB measures
Every atherogenic (artery-clogging) lipoprotein — LDL, VLDL, IDL and lipoprotein(a) — carries exactly one ApoB protein. So an ApoB measurement is effectively a direct count of how many of these particles are circulating, regardless of how much cholesterol each one happens to carry. Standard LDL cholesterol measures the cholesterol weight inside the particles, which can understate risk when particles are small and numerous.
Who should consider checking ApoB
Have you noticed any of these:
- family history of heart attack or stroke
- a 'normal' cholesterol result but wanting a clearer read on risk
- in your 40s or 50s and building a cardiovascular baseline
- training seriously and tracking your numbers over time
- heard about ApoB and want to know yours
- tracking the impact of diet, exercise or medication
How the test works
Single blood draw, usually run alongside a fasted lipid panel — an 8–12 hour fast is recommended for the most accurate companion lipids. Results back in 24 hours.
What "normal" can look like
ApoB is reported in g/L. Lower is generally considered better, and risk-focused discussion often cites optimal levels below roughly 0.8 g/L, with tighter targets for higher-risk individuals. The most useful pattern is discordance — a 'normal' LDL paired with a high ApoB — which is exactly the situation a standard lipid test can miss. Interpret your number with your doctor.
Where to get a ApoB test
ApoB is included in these panels:
- Cardiovascular Risk Panel — Beyond standard cholesterol — the advanced cardiovascular markers most GPs don't routinely check. $269
Frequently asked questions
What's the difference between ApoB and LDL cholesterol?
LDL cholesterol measures the cholesterol carried inside your LDL particles; ApoB counts the particles themselves. When the two disagree — a normal LDL but a high ApoB — ApoB is generally considered the better indicator of cardiovascular risk.
Do I need to fast?
ApoB itself is fairly stable, but it's usually measured with a lipid panel, so an 8–12 hour fast is recommended for accurate companion results.
Is a high ApoB a diagnosis?
No. Elevated ApoB is a risk marker, not a diagnosis. It's most useful read alongside your other cardiovascular markers and discussed with your doctor.