How often should I retest my blood biomarkers?

Short answer: it depends on which biomarker, your age and risk factors, and whether you’re changing medications or lifestyle. Below are practical general rules and specific intervals you can use as a starting point — always discuss with your clinician and confirm testing cadence for any medical condition or medication.

When to test (general guidance)

• Healthy adult, low risk (baseline): get a baseline panel (CBC, CMP/basic metabolic, lipid panel, fasting glucose or HbA1c, TSH, vitamin D, maybe CRP and ferritin). After that, repeat most routine panels every 1–3 years; lipids can be stretched to every 4–6 years if truly low risk.
• Age >45 or with risk factors (hypertension, family history, smoking, obesity): annual testing or as recommended by your clinician.
• New symptoms, unexplained weight change, fatigue, bruising, infection, bleeding, or new meds: test sooner — don’t wait for the routine interval.

Typical intervals for common tests

• Complete blood count (CBC): baseline, then annually if stable; sooner with symptoms or medication that affects blood counts.
• Basic/metabolic panel (electrolytes, kidney, liver): baseline, annually if stable; sooner if on meds that affect liver/kidney.
• Lipid panel: baseline, then every 4–6 years if low risk; every 1 year if higher risk or on/starting statin (see below).
• HbA1c (diabetes): every 3 months until controlled; then every 3–6 months. For prediabetes, at least annually.
• Fasting glucose: annually or with symptoms/risk.
• Thyroid (TSH ± free T4): baseline, then every 6–12 months if stable; 6–8 weeks after a dose change in thyroid medication.
• Vitamin D (25‑OH): baseline, then 8–12 weeks after starting repletion therapy to confirm response, or every 6–12 months if supplementing.
• Ferritin/iron studies: 8–12 weeks after starting iron therapy; otherwise as clinically indicated.
• CRP/high‑sensitivity CRP: every 6–12 months if tracking cardiovascular inflammation or after interventions.
• PSA (men): discuss with your clinician; screening intervals vary by age and risk (often every 1–2 years if screening).
• Testosterone (men with symptoms): morning sample; frequency depends on treatment — recheck 6–12 weeks after starting/changing therapy, then every 6–12 months.
• Medication monitoring (examples):
  • Statin: lipid panel 4–12 weeks after starting/dose change, then every 3–12 months.
  • Anticoagulants, immunosuppressants, mood stabilizers: follow drug-specific schedules—often much more frequent.

When to test sooner

• After starting or changing medications that affect labs.
• After beginning a major diet or exercise program (retest ~3 months to measure meaningful change).
• New symptoms or abnormal prior result.
• If you want to track response to supplements (e.g., vitamin D or iron) — see intervals above.

Practical tips

• Use the same lab and similar conditions (fasting vs nonfasting, time of day) for comparable results.
• Avoid over-testing — it can increase cost, anxiety, and false positives; focus on meaningful intervals where you expect change.
• Always confirm unexpected results with your clinician before acting.

Services and labs (options to consider)

• Quest Diagnostics or Labcorp — widely available, clinician-ordered, usually covered by insurance; good for comprehensive panels and follow-up testing.
• LetsGetChecked and Everlywell — convenient at‑home sample kits for common panels (cholesterol, A1c, thyroid, hormones); good if you prefer home collection, but confirm abnormal results with your doctor.
• InsideTracker — personalized biomarker panels with data-driven lifestyle recommendations and coaching; useful if you want deeper interpretation and trend analysis.
• Thorne — offers at‑home testing plus supplements and practitioner support; helpful if you want an integrative approach.
• For continuous glucose tracking, Levels partners with CGM manufacturers (useful for metabolic optimization but not a substitute for A1c).

Bottom line Make a baseline set of labs, then tailor retesting frequency to your risk profile, health goals, and any treatments. Talk with your primary care provider or specialist to set a specific schedule — they’ll balance clinical need, cost, and how soon a result should change management. If you’d like, tell me your age, health conditions, medications, and goals and I’ll suggest a more specific retesting plan.