Lab Testing FAQ
Common questions about at-home blood tests and direct-to-consumer lab services.
Are at-home lab tests as accurate as tests ordered by my doctor?▼
Yes—if they use professional labs like Quest or LabCorp.
Services like Marek Health, Function Health, and InsideTracker send you to the same Quest/LabCorp facilities your doctor would use. The samples are processed identically. Accuracy is the same.
Finger-prick at-home kits (Everlywell, LetsGetChecked) are slightly less accurate (±3-5% variance) but fine for routine screening and trending over time.
Do I need to fast before lab tests?▼
Depends on what you're testing:
- Fasting required (8-12 hours): Lipid panel, fasting glucose, insulin, comprehensive metabolic panels
- No fasting needed: Hormones (testosterone, estrogen), thyroid (TSH), vitamin D, CBC
- Morning best: Testosterone and cortisol (they fluctuate throughout the day)
Always check the specific requirements for your panel. Most services send detailed instructions.
What labs should I get as a baseline?▼
Start with these core markers (~$150-250 total):
- Complete Blood Count (CBC): Red/white blood cells, overall health
- Comprehensive Metabolic Panel (CMP): Kidney, liver function, electrolytes
- Lipid Panel: Cholesterol (total, LDL, HDL), triglycerides
- HbA1c: 3-month average blood sugar
- TSH: Thyroid function
- Vitamin D: Most people are deficient
This gives you a solid baseline. Add hormones (testosterone, estrogen) if optimizing performance or addressing symptoms.
Can I get lab tests without insurance?▼
Yes! That's the entire point of these services.
You don't need insurance, a doctor's referral, or pre-authorization. Just order, get tested, and receive results. Most services don't involve insurance at all—you pay cash/card directly.
However: You CAN use HSA/FSA funds for lab testing, since it's a qualified medical expense.
How often should I get labs done?▼
Depends on your situation:
- Healthy baseline: Once per year
- Optimizing/making changes: Every 3-6 months to track progress
- On medications (TRT, thyroid, etc.): Every 3-6 months or as prescribed
- Monitoring chronic conditions: Every 3 months or as recommended
Testing too frequently is wasteful—most markers don't change meaningfully week-to-week or even month-to-month.
What do I do if my results show something abnormal?▼
It depends on how abnormal:
Slightly out of range:
- Don't panic—single values can fluctuate
- Retest in a few weeks to confirm
- Consider context (diet, sleep, stress before the test)
- Services like Marek include physician consultation to interpret
Significantly abnormal or concerning values:
- See a doctor ASAP
- Bring your lab results with you
- Don't try to self-treat serious abnormalities
At-home testing is great for optimization and tracking, but not a replacement for medical diagnosis when something might be seriously wrong.