Lipoprotein(a)

Lipoprotein(a), or Lp(a), is a cholesterol particle you are largely born with. Roughly 80 to 90% of your level is fixed by a single gene, it stays nearly flat from your twenties onward, and a standard cholesterol panel does not measure it ¹. That combination makes Lp(a) a once-in-a-lifetime test for a lifetime risk, and it changes what 'high' means and what you can do about it.

What is Lp(a)?

Lp(a) is an LDL-like particle: a core of cholesterol wrapped around one apolipoprotein B (apoB) molecule, with an extra protein called apolipoprotein(a), or apo(a), bound on top ¹. That apo(a) tail is what makes Lp(a) its own risk factor rather than just more LDL. The apoB underneath means Lp(a) is counted whenever you measure apoB, but the apo(a) piece, and the inherited risk it carries, is invisible to your LDL number.

So apoB counts the Lp(a) particle in its total, but it cannot separate out how much of that count is inherited Lp(a) ⁶. A normal apoB does not rule out high Lp(a). The two tests answer different questions, which is why elevated Lp(a) has to be looked for directly. For the difference in full, see apolipoprotein B.

What does a high Lp(a) level mean?

Elevated Lp(a) is an independent, causal driver of atherosclerotic disease, meaning it adds risk on top of your LDL, blood pressure, and everything else ¹. The higher the number, the higher the lifetime risk, with no level at which the risk turns benign.

Lp(a) is reported two ways, and they are not interchangeable. Mass units (mg/dL) weigh the whole particle; molar units (nmol/L) count particles. Because apo(a) size varies between people, there is no single validated conversion, so a lab-swap or a rough multiplier can push you into the wrong tier ¹. Always check which unit your report uses.

Interactive

Read your Lp(a), in the right unit

mg/dL and nmol/L are not the same scale. Enter your value with its unit. Nothing leaves your browser.

Your Lp(a)

Unit

mg/dLnmol/L

Enter your Lp(a) value and choose its unit to see where it sits.

Educational, not a diagnosis. The mg/dL to nmol/L conversion is only approximate and depends on your particle size, so treat the other-unit figure as a rough range, not an exact value. Lp(a) is largely inherited; there is no proven way to meaningfully lower it, and any decisions belong with your clinician.

Don’t have your numbers yet?Get the complete panel, actually readStart with a comprehensive blood panel, then have every marker interpreted by LifeFrom’s medical AI and human reviewers, into plain language and a protocol you can act on. Not a lab that hands you a wall of numbers.Get started

Why is Lp(a) tested only once?

Your Lp(a) level is set almost entirely at birth and holds steady across decades, so a second test rarely tells you anything the first did not ¹. LDL cholesterol drifts with your diet, weight, thyroid, and medications; Lp(a) mostly ignores all of that. The chart below shows the contrast: LDL climbing and then dropping when treatment starts, while Lp(a) runs flat straight through.

Lp(a) measurement should be considered at least once in each adult person's lifetime to identify those with very high inherited levels.2019 ESC/EAS Guidelines for the management of dyslipidaemias, Eur Heart J 2020 [[2]]

How do you lower lipoprotein(a)?

As of 2026, no lifestyle change or standard cholesterol drug is proven to lower Lp(a) enough to change outcomes. Diet, exercise, and weight loss, which move LDL and triglycerides, barely touch Lp(a) ¹. Statins, the backbone of LDL treatment, do not lower Lp(a) and may nudge it slightly upward ¹³. That surprises people who assume a normal LDL on a statin has covered everything.

PCSK9-targeted agents, used mainly to drive LDL down further, lower Lp(a) by roughly a quarter, but no trial has yet shown that this drop by itself prevents heart attacks or strokes ¹. RNA-targeted drugs built specifically to cut Lp(a), pelacarsen (in the Lp(a)HORIZON trial) ⁴ and olpasiran (in OCEAN(a)) ⁷, lower it by 80% or more and are in phase 3 outcome trials. They are investigational, not available treatments, and the question of whether lowering Lp(a) lowers events is exactly what those trials are testing.

The practical lever today is everything around the Lp(a) number: driving LDL and apoB as low as your clinician recommends, controlling blood pressure, not smoking, and treating diabetes. High Lp(a) raises the stakes on every other risk factor, which is why aggressive control of the modifiable ones is the current standard of care ¹⁵.

Test your family: cascade screening

The single most useful thing a high Lp(a) result does is flag your relatives. Because the level is inherited through the LPA gene, a high number in you means your parents, siblings, and children each have meaningful odds of carrying it too, and many will not know ¹. This is called cascade screening, and it is the concrete action a high Lp(a) unlocks.

1. 1Confirm your own units and tierNote whether your result is in mg/dL or nmol/L and where it falls, so relatives can compare against the same scale.
2. 2Tell first-degree relativesParents, siblings, and children share the most genetic overlap with you and are the priority for testing.
3. 3Have each tested onceA single Lp(a) measurement settles the question for each person, since the level is stable for life.
4. 4Loop in a clinician for anyone who is highA high result in a relative is a reason for them to manage their other risk factors early, ideally before any symptoms appear.

Why Lp(a) also threatens the aortic valve

Lp(a) does more than fuel plaque in arteries. It carries oxidized phospholipids that deposit in the leaflets of the aortic valve and drive calcification, the slow stiffening and narrowing known as calcific aortic valve stenosis ¹. This is one risk that LDL alone does not predict, and it is part of why Lp(a) earns a separate look even when the rest of a panel is clean.

Lipoprotein(a) vs apoB vs LDL cholesterol

These three overlap but answer different questions. LDL-C measures cholesterol cargo. apoB counts atherogenic particles, including Lp(a). Lp(a) isolates the inherited particle none of the others can separate out.

A normal LDL, or even a normal apoB, does not clear you of high Lp(a), because Lp(a) is a specific inherited particle that only a direct Lp(a) test reveals. For how particle count and cholesterol cargo can disagree, see apolipoprotein B; for how the standard numbers fit together, see how to read your lipid panel and LDL cholesterol.

Who should get tested, and how it works

The 2019 ESC/EAS guideline recommends measuring Lp(a) at least once in every adult's lifetime ². The case is strongest if any of the following apply to you:

• Premature atherosclerotic disease: a heart attack, stroke, or stent earlier than expected (roughly before 55 in men, 65 in women) ²
• A family history of premature cardiovascular disease or of known high Lp(a)
• Familial hypercholesterolemia (FH) or very high LDL that runs in the family
• Recurrent cardiovascular events despite well-controlled LDL on treatment
• A first-degree relative found to have elevated Lp(a) (cascade screening)

Practically, Lp(a) is a single blood test that does not require fasting ², but it is a separate order that is not part of a routine lipid panel, so it has to be requested specifically. Insurance coverage is more likely when there is premature disease or a strong family history. When you get the result, confirm whether it is reported in mg/dL or nmol/L before comparing it to any threshold, and connect a high number to a clinician who can put it in context with the rest of your risk.