A lipoprotein(a) test is a simple blood draw that measures a specific type of cholesterol particle linked to heart disease and stroke. Unlike standard cholesterol panels, this test captures a genetic risk factor that affects roughly 20% of the population and can’t be detected any other way. Your levels are largely set by your DNA, stay relatively stable throughout life, and don’t respond to diet or exercise, which is why many experts now recommend testing at least once.
What Lipoprotein(a) Actually Is
Lipoprotein(a), often written as Lp(a) and pronounced “L-P-little-a,” is a cholesterol-carrying particle similar to LDL (the so-called “bad cholesterol”) but with an extra protein attached. That extra protein, called apolipoprotein(a), wraps around the particle and gives it two dangerous properties that regular LDL doesn’t have.
First, like LDL, Lp(a) deposits cholesterol into artery walls and drives plaque buildup. Second, because its extra protein closely resembles a natural clot-dissolving molecule called plasminogen, Lp(a) interferes with your body’s ability to break down blood clots. This dual action means elevated Lp(a) both accelerates plaque formation and increases the chance that a clot will form on top of that plaque and block an artery. The combination raises the risk of heart attack, stroke, and narrowing of the aortic valve.
Who Should Get Tested
Guidelines from multiple medical societies converge on a few key groups, though they differ slightly in scope. The American College of Cardiology and American Heart Association recommend Lp(a) testing for people at borderline or intermediate cardiovascular risk during primary prevention screening, as well as anyone with a family history of premature heart disease. The National Lipid Association echoes this, adding people with a personal history of early heart disease or significantly elevated LDL cholesterol.
European guidelines go further. The European Society of Cardiology and European Atherosclerosis Society recommend measuring Lp(a) once in a lifetime in all adults to catch those with extremely high levels. Their reasoning: very high Lp(a) (above 180 mg/dL or 430 nmol/L) carries a lifetime cardiovascular risk comparable to having familial hypercholesterolemia, a well-known genetic cholesterol disorder.
Because Lp(a) levels are genetically determined and remain stable over time, a single test typically gives you a reliable picture. Repeat testing is generally unnecessary unless a health condition that temporarily affects results, like kidney disease or an underactive thyroid, has been treated.
How the Test Works
The test itself is a standard blood draw, usually from a vein in your arm. Most labs require you to fast for 9 to 12 hours beforehand, though your provider will confirm this since requirements vary by lab. Before your test, let your provider know if you’ve been taking niacin supplements, aspirin, oral estrogen hormones, or drinking alcohol, as these can influence results.
Lp(a) is not included in a routine lipid panel. You have to request it specifically, or your provider has to order it separately. This is one reason the particle flies under the radar for so many people: standard cholesterol testing simply doesn’t measure it.
Understanding Your Results
Results are reported in either milligrams per deciliter (mg/dL) or nanomoles per liter (nmol/L), depending on the lab. The CDC defines high Lp(a) as greater than 50 mg/dL (or 125 nmol/L). European guidelines flag an even higher threshold of 180 mg/dL (430 nmol/L) as carrying risk equivalent to a genetic cholesterol disorder. It’s worth noting that these two units don’t convert neatly because of variation in particle size, so comparing results across different measurement systems can be tricky. Make sure you know which unit your lab used.
One critical point: your Lp(a) level can be dangerously high even if your standard LDL cholesterol looks perfectly normal. Research estimates that 20 to 30% of the population may have their cardiovascular risk underestimated because elevated Lp(a) hides behind otherwise reassuring lipid panels. This is especially relevant for women under 40 with low LDL cholesterol, who may carry significant hidden risk from high Lp(a) that wouldn’t show up on a standard panel.
Why Standard Treatments Don’t Lower Lp(a)
This is where Lp(a) differs most dramatically from regular cholesterol. Your Lp(a) level is determined by variations in the LPA gene you inherited. Statins, the most commonly prescribed cholesterol drugs, don’t lower Lp(a). Neither do dietary changes, exercise, or weight loss. Some statins may even raise Lp(a) slightly, though they still provide cardiovascular benefit through other mechanisms.
There are currently no FDA-approved medications specifically designed to lower Lp(a). However, two drugs are in advanced clinical trials. One is an injection given once monthly, and the other is given every 12 weeks. In early-phase studies, one of these reduced Lp(a) levels by more than 90% over 48 weeks. Both are now in large Phase 3 trials designed to determine whether lowering Lp(a) actually reduces heart attacks and strokes, not just the number on a lab report.
What a High Result Means for You
Knowing you have elevated Lp(a) doesn’t leave you without options, even without a targeted drug. The practical value of the test is that it changes how aggressively you and your provider manage every other risk factor you can control. If your Lp(a) is high, there’s a stronger case for keeping LDL cholesterol as low as possible, managing blood pressure tightly, maintaining a healthy weight, and avoiding smoking. Think of it as recalibrating your overall risk picture: you’re starting with a genetic disadvantage, so the controllable factors matter even more.
A high result also has implications for your family. Because Lp(a) is inherited, an elevated level in one person means first-degree relatives (parents, siblings, children) have roughly a 50% chance of carrying the same risk. Testing family members, especially those who wouldn’t otherwise be flagged as high risk, can catch a hidden vulnerability early.