Blood tests for long-term health and longevity

The tests that matter most

Most important first. Each one links to its full page, where the note for this group sits near the top.

• Apolipoprotein B (ApoB)

  The 2026 U.S. cholesterol guideline counts a high ApoB as a factor that adds to heart risk, and says ApoB predicts risk better than LDL when the two disagree. For people on cholesterol treatment, it finds ApoB useful once LDL and non-HDL goals are met.

  Source: Circulation (2026)

  Usual adult range

  up to 90 mg/dL

• Lipoprotein(a), molar (nmol/L)

  Lp(a) is mostly inherited. The 2026 U.S. cholesterol guideline newly recommends measuring it at least once in all adults, and counts a high level as a factor that adds to heart risk. One test is generally enough unless something can shift the level, such as the menopause transition or kidney, liver or thyroid disease.

  Source: Circulation (2026)

  Usual adult range

  up to 75 nmol/L

• C-Reactive Protein (CRP, incl. hs-CRP)

  If high-sensitivity CRP (hs-CRP) is measured, the 2026 U.S. cholesterol guideline counts a level of 2 mg/L or more on more than one occasion, with no other cause found, as a factor that adds to heart risk.

  Source: Circulation (2026)

  Usual adult range

  0–5 mg/L

• Hemoglobin A1c (HbA1c)

  The ADA suggests diabetes screening for all adults starting at age 35, repeated at least every 3 years when results are normal and yearly with prediabetes. A1c can mislead with anemia, recent blood loss or some hemoglobin variants, and the ADA suggests glucose-based criteria in those cases.

  Source: American Diabetes Association (2026)

  Usual adult range

  4.8–5.6 %

• eGFR (Creatinine + Cystatin C, CKD-EPI 2021)

  Creatinine depends on muscle and diet, so people who do extreme sport or bodybuilding, eat a high-protein diet or take creatine supplements can get a misleading creatinine-based eGFR. KDIGO recommends adding cystatin C when the creatinine-based result is less accurate and would affect decisions.

  Source: Kidney Disease: Improving Global Outcomes (2024)

  Usual adult range

  60 and above mL/min/1.73 m²

• Insulin

  An ADA workgroup reported in 2010 that commercial insulin tests give a range of values for the same sample, so fasting insulin results from different labs are not directly comparable. A 2023 international guideline on PCOS (also called PMOS) says insulin tests in clinical use are of limited value and not recommended in routine PCOS care.

  Sources: Diabetes Care (2010) and The Journal of Clinical Endocrinology & Metabolism (2023)

  Usual adult range

  2.6–24.9 µIU/mL

• HOMA-IR

  HOMA-IR is worked out from fasting insulin and glucose, so it carries the same lab-to-lab problem. In 2010, an ADA workgroup said insulin sensitivity measures were used only in research, had no clinical applications yet, and gave results that were not comparable from one study to the next.

  Source: Diabetes Care (2010)

• Alanine Aminotransferase (ALT)

  ALT is a liver enzyme on standard blood panels, and it is often ordered with GGT and other liver tests. Hard exercise before a test is one of the things MedlinePlus lists as able to change lab results.

  Sources: MedlinePlus and MedlinePlus

  Men, 18+

  0–44 U/L

  Women, 18+

  0–32 U/L

• Gamma-Glutamyl Transferase (GGT)

  GGT is a liver enzyme that alcohol raises. Smoking, some medicines and supplements, and conditions such as diabetes and heart failure can also affect it, so a high GGT on its own doesn't show the cause.

  Source: MedlinePlus

  Men, 18+

  0–65 U/L

  Women, 18+

  0–60 U/L

• Vitamin D (25-Hydroxy)

  The Endocrine Society suggests against routine vitamin D testing in the general population at every adult age. It also says the vitamin D levels that bring specific health benefits have not been set in clinical trials.

  Source: Endocrine Society (2024)

  Usual adult range

  30–100 ng/mL

• Omega-3 Index (EPA+DHA)

  A pooled analysis of 17 cohort studies linked higher blood levels of EPA and DHA, the two omega-3 fats this test adds up, with a lower risk of death. It measured them in red cells or plasma rather than reporting the omega-3 index by name, and as an observational study it can't rule out that higher levels partly reflect a healthy lifestyle.

  Source: Nature Communications (2021)

Ranges shown are the usual adult ranges labs print. The range on your own report is the one your result is judged against.

Also written for

• High cholesterol or heart risk
• Prediabetes or diabetes
• Keto or low-carb eating
• Strength training