Function Health

What Is Function Health?

Function Health is a membership-based blood testing service that measures 110+ lab markers in a single panel — roughly 3-4 times the number of biomarkers in a standard physician-ordered blood test. Founded by Jonathan Johnson, former CEO of Overstock.com, the platform takes a volume-first approach: test as many clinically relevant markers as possible, present them with optimal ranges, and let members track trends over time.

The service operates on a $499/year membership that includes two comprehensive blood draws per year at Labcorp locations. This positions Function Health as one of the most cost-effective ways to access a broad biomarker panel, particularly for markers that many physicians do not routinely order, such as ApoB, insulin, homocysteine, and advanced thyroid panels.

How It Works

After enrolling in the annual membership, you schedule a blood draw at a Labcorp location. The panel covers over 110 markers spanning metabolic health, cardiovascular risk, hormones, vitamins and minerals, organ function, inflammation, autoimmune indicators, and cancer screening markers. Results typically arrive within 7-10 business days.

The Function Health dashboard displays each marker against two reference frameworks: the standard medical reference range (what your doctor uses) and Function's "optimal range" — a narrower band derived from longevity research and preventive medicine literature. Markers outside the optimal range are flagged with color coding and context about potential health implications.

Critically, Function Health does not provide prescriptive recommendations. Unlike InsideTracker, which tells you what to eat and supplement, Function surfaces the data and context but leaves intervention decisions to you and your healthcare provider. The platform includes a physician review of your results, and you can share your dashboard with your own doctor.

Key Features

• 110+ biomarkers per panel: The most comprehensive consumer blood test available, covering metabolic, cardiovascular, hormonal, nutritional, organ function, inflammatory, and cancer screening markers
• Optimal range framework: Each marker is mapped against both standard medical ranges and research-backed optimal ranges for proactive health management
• Two tests per year: Membership includes biannual testing for longitudinal trend tracking
• Physician review included: A licensed physician reviews every panel, with the option to discuss results
• Labcorp network: Blood draws at Labcorp locations, which are widely available across the United States

Our Testing Experience

The breadth of Function Health's panel is genuinely impressive. Markers like ApoB (a superior cardiovascular risk predictor to standard LDL cholesterol), fasting insulin (an early metabolic health indicator), and comprehensive thyroid panels (TSH, Free T3, Free T4, thyroid antibodies) are tests that most people would need to specifically request — and sometimes argue for — from their primary care physician. Function includes all of them by default. The panel also covers markers that even proactive doctors rarely order: lipoprotein(a), which is a genetically determined cardiovascular risk factor that most people never discover unless specifically tested; DHEA-S, an adrenal marker that tracks stress resilience and aging; and a full iron panel (serum iron, ferritin, TIBC, transferrin saturation) rather than just the ferritin-only test common in standard physicals.

The dashboard is clean and well-organized, with markers grouped by health category. The dual reference range display (standard vs. optimal) is immediately useful: you can quickly identify markers that your doctor would call "normal" but that fall outside the optimal range favored by longevity-focused physicians. For example, a fasting glucose of 95 mg/dL is well within the standard reference range (65-99) but outside Function's optimal range (70-85), prompting earlier attention to metabolic health. Similarly, a standard LDL cholesterol of 120 mg/dL might pass a typical checkup, but Function's inclusion of ApoB testing provides a more granular cardiovascular risk assessment.

The biannual testing cadence enables meaningful trend analysis. Seeing how your markers shift between your first and second tests — particularly in response to dietary, exercise, or supplement changes — transforms static lab numbers into a dynamic health narrative. The dashboard includes trend charts that make six-month comparisons intuitive.

The limitation is interpretation depth. Function tells you that a marker is suboptimal but does not prescribe specific foods, supplements, or lifestyle changes the way InsideTracker does. This design is intentional — Function positions itself as a data layer, not a recommendation engine — but it means you need either a knowledgeable healthcare provider or your own research capacity to translate flagged markers into action. For users without a functional medicine doctor or strong self-research habits, the sheer volume of data can feel overwhelming rather than empowering. The 7-10 day result window is also longer than InsideTracker's typical 5-7 days.

The Bottom Line

Function Health delivers the most comprehensive consumer blood panel available at a competitive price point. For $499/year, you receive two tests totaling 220+ data points — a volume of testing that would cost thousands through traditional ordering and insurance billing. The platform excels at surfacing markers you did not know to ask about and establishing longitudinal baselines. The tradeoff is a lack of prescriptive guidance: you get the data, but turning it into action requires additional effort or a proactive healthcare provider.