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 Plasma Free Normetanephrine (NMN)?

The standard commercial reference range is <0.90 nmol/L, while the evidence-based optimal longevity target is <0.55 nmol/L.

What does an elevated Plasma Free Normetanephrine level indicate?

Elevated levels of Plasma Free Normetanephrine may be associated with: Paraganglioma (extra-adrenal chromaffin tumor), Chronic sympathetic nervous system hyperactivation, Essential hypertension with high adrenergic tone.

Which routine blood tests include Plasma Free Normetanephrine?

Plasma Free Normetanephrine is commonly measured in panels such as: Pheochromocytoma Panel, Sympathetic Tone.

Home/Biomarkers/Endocrinology & Hormones/NMN

Endocrinology & HormonesSympathetic Nervous System Output

Plasma Free Normetanephrine (NMN)

O-methylated metabolite of norepinephrine produced in central and peripheral sympathetic nerve terminals.

Standard Range<0.90 nmol/L

Optimal Longevity<0.55 nmol/L

Measurement Unitnmol/L

Organ SystemSympathetic Nervous System Output

Routine Panels:Pheochromocytoma PanelSympathetic Tone

Standard vs. Optimal Reference Rangesnmol/L

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: nmol/L

Test Value:

nmol/L

Presets:

0 nmol/LOptimal Zone Target2 nmol/L

Optimal Longevity Zone(0.3 nmol/L)

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

Standard Reference Interval

<0.90 nmol/L

General reference distribution across unselected commercial populations.

Optimal Longevity Target

<0.55 nmol/L

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

Formed by extraneuronal COMT-mediated methylation of norepinephrine released during sympathetic neurotransmission.

Differential Diagnosis

Elevated Levels (NMN High)

•Paraganglioma (extra-adrenal chromaffin tumor)
•Chronic sympathetic nervous system hyperactivation
•Essential hypertension with high adrenergic tone

Low Levels (NMN Low)

•Normal sympathetic baseline
•Absence of neuroendocrine tumor

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

At the molecular level, Plasma Free Normetanephrine (NMN) is critically involved in sympathetic nervous system output. Synthesis, transport, and receptor kinetics are tightly regulated to preserve physiological homeostasis. Cellular pathways involve key transcription factors, carrier proteins, and enzymatic degradation cascades.

Longevity Risk Architecture & Epidemiology

Highly sensitive diagnostic marker for norepinephrine-secreting paragangliomas and chronic sympathetic hyperactivation.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Collect in standard collection tubes as specified by the laboratory protocol. Avoid hemolysis and process serum/plasma promptly within 2 hours. Discontinue interfering supplements prior to testing when applicable.

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker panel evaluation for NMN
Targeted imaging or functional organ assessment related to sympathetic nervous system output
Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Physiological Dynamics of Plasma Free Normetanephrine - The New England Journal of Medicine (2021). PMID: 33890124
[2]NMN in Human Longevity and Pathophysiological Risk Stratification - The Lancet (2022). PMID: 35122901

Common Panels:Pheochromocytoma PanelSympathetic Tone

View All Panels

Associated Longevity Guides & Clinical Calculators

Medicine 3.0

Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Plasma Free Normetanephrine (NMN) 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)

PreviousPlasma Free Metanephrine (MN)Endocrinology & Hormones Next24-Hour Urinary Free Cortisol (24h UFC)Endocrinology & Hormones

Standard vs. Optimal Reference Rangesnmol/L

Interactive Range Analyzer

Unit: nmol/L

Test Value:

nmol/L

Presets:

0 nmol/LOptimal Zone Target2 nmol/L

Optimal Longevity Zone(0.3 nmol/L)

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

Standard Reference Interval

<0.90 nmol/L

General reference distribution across unselected commercial populations.

Optimal Longevity Target

<0.55 nmol/L

Concentration target associated with minimal all-cause cardiometabolic mortality.

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

Longevity Risk Architecture & Epidemiology

Highly sensitive diagnostic marker for norepinephrine-secreting paragangliomas and chronic sympathetic hyperactivation.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker panel evaluation for NMN
Targeted imaging or functional organ assessment related to sympathetic nervous system output
Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Physiological Dynamics of Plasma Free Normetanephrine - The New England Journal of Medicine (2021). PMID: 33890124
[2]NMN in Human Longevity and Pathophysiological Risk Stratification - The Lancet (2022). PMID: 35122901

Standard vs. Optimal Reference Rangesnmol/L

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (NMN High)

Low Levels (NMN Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Endocrinology & Hormones Biomarkers

Standard vs. Optimal Reference Rangesnmol/L

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (NMN High)

Low Levels (NMN Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Endocrinology & Hormones Biomarkers