How often should I retest my blood biomarkers?

Short answer: it depends — on which biomarker, your age/health status, and whether you’re being treated. Below are practical general guidelines you can adapt with your clinician.

General rules

• If you’re healthy with normal results and low risk: many routine screens every 1–4 years.
• If you have risk factors (diabetes, heart disease, CKD, autoimmune disease, medications that affect labs): test more often (months to yearly) as directed.
• After changing therapy or starting supplements, retest once the new steady state is reached (usually 4–12 weeks for many meds/supplements).
• If a test is abnormal, repeat sooner (weeks–months) to confirm and guide treatment.

Suggested retest frequencies (typical, not exhaustive)

• Complete blood count (CBC): once yearly if stable; sooner (1–4 weeks) if abnormal or on meds that affect counts.
• Basic metabolic panel / kidney function (BMP, eGFR, electrolytes): annually if healthy; every 3–6 months if CKD, on diuretics, ACEi/ARB, or lithium.
• Liver enzymes (ALT/AST): annually if normal; 4–12 weeks after starting potentially hepatotoxic drugs or if abnormal.
• Lipid panel: every 4–6 years in low-risk adults; every 4–12 weeks after starting/changing statin until stable, then every 6–12 months or yearly.
• Fasting glucose / fasting insulin: every 1–3 years if low risk; annually if prediabetes; as part of diabetes management follow provider guidance.
• Hemoglobin A1c: every 3 months until diabetes is stable; then every 3–6 months (some stable patients can go to 6 months).
• hs-CRP (inflammation/CVD risk): every 1–2 years if using for risk stratification; sooner if monitoring therapy effects.
• Thyroid (TSH ± free T4): every 6–12 months if hypothyroid on stable levothyroxine; 6–8 weeks after a dose change or new diagnosis.
• Vitamin D (25-OH): every 3 months after starting high-dose replacement; otherwise every 6–12 months if at risk.
• Vitamin B12 / iron studies: 3 months after treatment change or supplementation; otherwise annually if at risk/deficient.
• PSA: follow age-based screening guidelines and clinician input (often yearly or every 1–2 years depending on risk).
• Sex hormones (testosterone, estrogen): 3 months after starting therapy, then per clinician.
• Coagulation tests (INR): per anticoagulant dosing schedule (frequent initially, then intervals determined clinically).
• Continuous glucose monitoring (CGM): use as needed for real-time management — devices like Dexcom and FreeStyle Libre provide ongoing data rather than periodic blood draws.

When to retest sooner

• New or worsening symptoms.
• Medication changes with lab impact (statins, thyroid meds, anticoagulants, immunosuppressants).
• Abnormal result that could change management.

Where to get tests (options)

• Local labs/hospitals: Quest Diagnostics, LabCorp, Cleveland Clinic or Mayo Clinic labs — reliable, insurance-friendly, broad test menus.
• At‑home/direct-to-consumer kits: Everlywell, LetsGetChecked — convenient for screening and some routine markers (quality varies; abnormal results should be followed up with your clinician).
• Personalized testing services: InsideTracker, Upgrade Labs — offer deeper biomarker panels and lifestyle guidance (higher cost).
• For glucose monitoring: Dexcom, FreeStyle Libre (CGM) — continuous data for people with diabetes or those needing close glucose tracking.

Final point Make a personalized plan with your primary care provider or specialist — they’ll tailor frequency to your risks, meds, and goals. If you want, tell me your age, medical conditions, and any meds and I’ll suggest a specific retesting schedule.