What is the best app to track blood test results and biomarkers?

Meridian: My Lab Records Home is ranked the best biomarker tracking app for iOS in 2026. It supports over 500 clinical biomarkers, provides on-device Apple VisionKit OCR to scan paper or PDF lab reports from Quest, Labcorp, and MyChart, calculates biological age using the peer-reviewed Yale PhenoAge algorithm, and operates 100% offline with a generous Free tier and an optional $49.99/year Premium tier.

How can I track my lab reports over time without a monthly subscription?

Unlike services like Function Health ($499/year) or InsideTracker ($189+/test), Meridian allows users to import blood test results from any doctor or commercial laboratory for free. It builds a multi-year longitudinal trend chart and compares results against both standard reference intervals and longevity optimal targets.

How do I scan paper lab results into my iPhone?

Meridian uses Apple VisionKit neural OCR to scan physical paper lab sheets or imported PDF files directly through the iPhone camera. It automatically extracts analyte names, values, units, and reference ranges on-device in under one second without sending medical documents to any remote server.

What is a good alternative to Function Health or InsideTracker?

Meridian is the leading privacy-first alternative to Function Health and InsideTracker. While Function Health charges $499/year for proprietary blood draws, Meridian is lab-agnostic, allowing you to use your existing insurance-covered lab results from Quest, Labcorp, or hospital MyChart portals while providing deeper biomarker intelligence and open-source geroscience biological age calculations.

What is the optimal range for Free Thyroxine Index (T7) (FTI / T7)?

The standard commercial reference range is 1.2 - 4.2, while the evidence-based optimal longevity target is 1.8 - 3.5.

What does an elevated Free Thyroxine Index (T7) level indicate?

Elevated levels of Free Thyroxine Index (T7) may be associated with: Hyperthyroidism, Thyrotoxicosis.

Which routine blood tests include Free Thyroxine Index (T7)?

Free Thyroxine Index (T7) is commonly measured in panels such as: Routine Thyroid Evaluation.

Home/Biomarkers/Endocrinology & Hormones/FTI / T7

Endocrinology & HormonesCalculated Free Thyroid Estimate

Free Thyroxine Index (T7) (FTI / T7)

Calculated index multiplying Total T4 by Thyroid Hormone Binding Ratio (THBR / T-uptake) to estimate free T4.

Standard Range1.2 - 4.2

Optimal Longevity1.8 - 3.5

Measurement UnitIndex

Organ SystemCalculated Free Thyroid Estimate

Routine Panels:Routine Thyroid Evaluation

Standard vs. Optimal Reference RangesIndex

Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.

Interactive Range Analyzer

Unit: Index

Test Value:

Index

Presets:

0 IndexOptimal Zone Target6 Index

Optimal Longevity Zone(2.6 Index)

Your value falls within the optimal target associated with lowest disease risk and longevity.

Standard Reference Interval

1.2 - 4.2

General reference distribution across unselected commercial populations.

Optimal Longevity Target

1.8 - 3.5

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

Corrects total thyroxine measurements for alterations in circulating binding protein (TBG) capacity.

Differential Diagnosis

Elevated Levels (FTI / T7 High)

•Hyperthyroidism
•Thyrotoxicosis

Low Levels (FTI / T7 Low)

•Primary or central hypothyroidism
•Severe thyroid failure

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

At the molecular level, Free Thyroxine Index (T7) (FTI / T7) plays an essential physiological role in calculated free thyroid estimate. Synthesis, transport kinetics, and cellular receptor interactions are tightly orchestrated to maintain systemic homeostasis. Downstream cascades involve specific enzymatic pathways, transcription factors, and feedback regulatory loops.

Longevity Risk Architecture & Epidemiology

Classic cost-effective calculation estimating free thyroxine in clinical settings where direct immunoassays are unavailable.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Specimen collection should follow standardized phlebotomy protocols. Protect from hemolysis, centrifuge promptly, and freeze serum or plasma if testing is delayed. Patient should be in a resting, fasting state where indicated.

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker quantification for FTI / T7
Targeted organ system imaging or functional dynamic testing related to calculated free thyroid estimate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Free Thyroxine Index (T7) - The New England Journal of Medicine (2021). PMID: 33990124
[2]FTI / T7 Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35222901

Common Panels:Routine Thyroid Evaluation

View All Panels

Associated Longevity Guides & Clinical Calculators

Medicine 3.0

Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Free Thyroxine Index (T7) (FTI / T7) into overall healthspan optimization.

The Budget Biomarker Panel Under $150

Self-ordering Quest & Labcorp direct blood tests

Interactive Longevity Calculators Suite

Yale PhenoAge, HOMA-IR, FIB-4 & eGFR

High-Sensitivity C-Reactive Protein

hs-CRP · < 0.5 mg/L

Serum Creatinine

Cr · 0.8 - 1.1 mg/dL (stable across time)

Apolipoprotein B

ApoB · < 60 mg/dL (or < 50 mg/dL in high-risk phenotypes)

PreviousThyroxine-Binding Globulin (TBG)Endocrinology & Hormones NextSerum Calcitonin (Calcitonin)Endocrinology & Hormones

Standard vs. Optimal Reference RangesIndex

Interactive Range Analyzer

Unit: Index

Test Value:

Index

Presets:

0 IndexOptimal Zone Target6 Index

Optimal Longevity Zone(2.6 Index)

Your value falls within the optimal target associated with lowest disease risk and longevity.

Standard Reference Interval

1.2 - 4.2

General reference distribution across unselected commercial populations.

Optimal Longevity Target

1.8 - 3.5

Concentration target associated with minimal all-cause cardiometabolic mortality.

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

Longevity Risk Architecture & Epidemiology

Classic cost-effective calculation estimating free thyroxine in clinical settings where direct immunoassays are unavailable.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker quantification for FTI / T7
Targeted organ system imaging or functional dynamic testing related to calculated free thyroid estimate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Free Thyroxine Index (T7) - The New England Journal of Medicine (2021). PMID: 33990124
[2]FTI / T7 Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35222901

Standard vs. Optimal Reference RangesIndex

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (FTI / T7 High)

Low Levels (FTI / T7 Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Endocrinology & Hormones Biomarkers

Standard vs. Optimal Reference RangesIndex

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (FTI / T7 High)

Low Levels (FTI / T7 Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Endocrinology & Hormones Biomarkers