Lp(a) is an LDL-like particle almost entirely determined by genetics. It independently raises cardiovascular risk — and the 2026 ACC/AHA guidelines now recommend that every adult test it at least once. Most people never have.
Lipoprotein(a) — pronounced "L-P-little-a" — is a lipoprotein particle structurally similar to LDL but with an additional protein called apolipoprotein(a) covalently bonded to it. This extra protein makes Lp(a) more adhesive to arterial walls, more prone to triggering thrombosis, and more atherogenic than a comparably sized LDL particle.[1]
What makes Lp(a) unlike almost any other cardiovascular biomarker: its concentration in your blood is 80–90% determined by genetics, specifically by the LPA gene. Diet, exercise, statins, and most other lipid-lowering strategies have minimal effect on Lp(a). You either have it or you don't — and your level stays essentially constant throughout your adult life.[2]
This is why the 2026 ACC/AHA guideline recommends testing it just once. Unlike ApoB or fasting insulin — which respond to lifestyle and require retesting — Lp(a) is a one-time risk stratification tool. You need the number, you need to know what it means, and you plan accordingly.
About 20% of adults globally have Lp(a) levels above 125 nmol/L (approximately 50 mg/dL) — the threshold at which the 2026 ACC/AHA guideline considers cardiovascular risk substantially elevated.[3] At very high levels (above 300 nmol/L), risk is comparable to heterozygous familial hypercholesterolemia.
Because Lp(a) elevation is genetic and largely asymptomatic, the only way to know is to test. The standard lipid panel your doctor orders does not include Lp(a). You have to ask for it specifically — or order it directly.
The guideline's rationale for universal testing is straightforward: elevated Lp(a) changes how aggressively other risk factors should be managed, including LDL-C targets and the threshold for treatment. Knowing your number informs a cascade of downstream decisions.
Both are atherogenic particles. Both predict cardiovascular risk better than LDL-C alone. But they work through different mechanisms and require different responses:
| Lp(a) | ApoB | |
|---|---|---|
| What it is | LDL-like particle + apo(a) protein | Protein on every atherogenic particle |
| Determined by | Genetics (~80–90%) | Lifestyle + genetics |
| Responds to lifestyle | Minimally | Significantly |
| Responds to statins | Minimally (may slightly increase) | Yes — meaningfully |
| How often to test | Once in lifetime | Every 90 days if elevated |
| Optimal level | Below 75 nmol/L (<30 mg/dL) | Below 80 mg/dL |
| High-risk threshold | Above 125 nmol/L (50 mg/dL) | Above 100 mg/dL |
| Actionability | Informs risk — drives ApoB + LDL targets lower | Directly modifiable target |
Reference ranges vary by lab and units used (nmol/L vs mg/dL). Conversion is not exact — 125 nmol/L ≈ 50 mg/dL but this varies by particle size. Use nmol/L where available as it is more accurate.
nmol/L (preferred) or mg/dL. Check which your lab uses.
Below 75 nmol/L (<30 mg/dL) — low risk zone
Above 125 nmol/L (≈50 mg/dL) — Class I recommendation to flag as risk-enhancing
Above 300 nmol/L (≈120 mg/dL) — risk comparable to familial hypercholesterolemia
Once in a lifetime. Levels are genetically stable.
~80–90% genetic. If your Lp(a) is elevated, test first-degree family members.
Direct-to-consumer. No doctor required.
The 2026 ACC/AHA/Multisociety Dyslipidemia Guideline — the first update since 2018 — elevated Lp(a)'s clinical standing substantially. Key provisions relevant to health optimization:
Lp(a) measurement is now recommended at least once in all adults. Class I is the highest level of recommendation — meaning the benefit substantially outweighs the risk and the evidence is strong. This moves Lp(a) from a selective test for high-risk patients to a population-level screening recommendation.
Above 125 nmol/L, Lp(a) is designated a risk-enhancing factor that should prompt more aggressive LDL-C management. If your LDL-C target was 100 mg/dL, elevated Lp(a) may push it to 70 mg/dL. If you were at the borderline for statin treatment, elevated Lp(a) tips the decision toward treatment.
Lp(a) is inherited in an autosomal dominant pattern. Elevated Lp(a) in one family member should prompt testing of first-degree relatives — parents, siblings, children — because they have a 50% chance of inheriting it.
Unlike ApoB, which responds to lifestyle and existing medications, Lp(a)-specific treatments (including RNA-interference therapies such as pelacarsen and olpasiran) are in advanced clinical trials. The guideline anticipates these will change management substantially over the next few years.
Lp(a) is not part of a standard lipid panel. You need to request it specifically — your doctor may not offer it unprompted even after the 2026 guideline, as clinical adoption of new recommendations typically lags by 2–3 years.
Request "lipoprotein(a)" or "Lp(a)" specifically. Mention the 2026 ACC/AHA guideline if needed. It is a standard lab test available at all major clinical labs. It may or may not be covered by insurance depending on your plan and risk profile.
Order without a doctor's referral. Results in 3–5 days. You own your results directly.
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Function Health and InsideTracker include Lp(a) in their full panels alongside 100+ other biomarkers — useful if you want Lp(a) as part of a complete baseline rather than a single test.
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Yes. The 2026 ACC/AHA guideline makes universal testing a Class I recommendation, but clinical adoption typically lags guidelines by 2–3 years. Many physicians are aware but won't order it unprompted. Ask specifically for "lipoprotein(a) testing" and reference the 2026 ACC/AHA guideline if needed. Alternatively, order directly through Quest Health.
See the full interpretation guide: What high Lp(a) means and what to do →. The short version: elevated Lp(a) changes how aggressively you should manage other modifiable risk factors — ApoB, LDL-C, inflammation, blood pressure. It doesn't mean immediate medication; it means tightening everything else.
Normal Lp(a) removes one inherited risk factor — it doesn't eliminate cardiovascular risk. ApoB, fasting insulin, blood pressure, hs-CRP, and lifestyle factors remain important. A normal Lp(a) just means your inherited particle risk is low.
Both are used, and conversion is not exact (varies by particle size). Roughly: 125 nmol/L ≈ 50 mg/dL; 300 nmol/L ≈ 120 mg/dL. Where possible, use nmol/L as it is more standardized. Check your lab report header for the unit used.
No. Unlike fasting insulin or triglycerides, Lp(a) is not significantly affected by food intake. You can test at any time of day without fasting preparation.
Lp(a) is one of the clearest cases where DNA matters. SelfDecode can help you review genetic risk patterns, connect them with blood markers, and turn that information into personalized diet, supplement, and lifestyle recommendations.
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Lp(a) is one piece. ApoB, hs-CRP, fasting insulin, and blood pressure complete it. The Stack Analyzer tells you which to prioritize for your goals.