What ApoB measures
ApoB is a protein on the surface of LDL, VLDL, IDL and Lp(a) particles – the lipoproteins that can carry cholesterol into artery walls. Each of these particles carries exactly one ApoB molecule, so your ApoB level is effectively a count of them.
A standard cholesterol test measures how much cholesterol those particles carry. ApoB measures how many particles there are. The two usually move together, but not always: some people have an ordinary LDL cholesterol result but a higher number of smaller particles.
Why it matters for longevity
Research over several decades links a higher number of ApoB-containing particles with more build-up of plaque in the arteries over time. European cardiology guidelines (ESC/EAS) describe ApoB as a useful additional measure alongside LDL cholesterol, particularly for people with high triglycerides, diabetes or excess weight.
For longevity-focused testing, ApoB is popular because it is a single, direct number that can be tracked over years. It is still one piece of a bigger picture: your doctor will consider it together with blood pressure, smoking, family history and your other results.
How it's tested
- Sample
- Finger-prick or venous, depending on the provider
- Fasting
- Usually not required – follow your provider's instructions
- Units
- g/L in the UK and Europe, mg/dL in the US
Before you test
- Test at a similar time of day each time you re-test, so results are comparable.
- Tell the provider about lipid-lowering medicines you take.
What can affect your result
- Recent changes in diet, weight or alcohol intake
- Lipid-lowering and some other medicines
- Thyroid function – ApoB can be higher when the thyroid is underactive
- Pregnancy
Talking to your doctor about your result
Your report will show your result next to the lab's reference range. Ranges differ between labs and units, and a result inside or outside the range isn't a diagnosis on its own. Share the full report with your doctor – especially if a result is flagged, you have symptoms, or there's a family history that concerns you. Don't start, stop or change any medicine or supplement based on a home test without medical advice.
What a ApoB test costs
In our European price check (12 October 2026), the cheapest ApoB test we found was €78 (SYNLAB, Finland); the cheapest option in the most expensive country was €200 (Germany). Lab prices often exclude a small blood-draw or visit fee. It can be better value as part of a panel if you want several of the core markers. See every price by country in our European blood test price guide.
ApoB: common questions
Is ApoB better than LDL cholesterol?
They measure different things. LDL cholesterol measures the cholesterol inside particles; ApoB counts the particles themselves. Many doctors look at both, and ApoB adds the most information when the two disagree. Your doctor can tell you which matters most in your situation.
Do I need to fast for an ApoB test?
Usually not, because ApoB changes little after a meal. Some providers still ask you to fast if ApoB is part of a bigger panel that includes triglycerides, so follow their instructions.
Can I test ApoB with a finger-prick kit?
Some at-home kits include ApoB on a finger-prick sample; others only offer it with a venous draw. The comparison table shows which providers include it and how the sample is taken.
Related markers
Sources
[PLACEHOLDER: 2–4 primary references (guidelines, consensus statements) confirmed by the medical reviewer]