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 Cystathionine (Cystathionine)?

The standard commercial reference range is 40 - 250 nmol/L, while the evidence-based optimal longevity target is 60 - 180 nmol/L.

What does an elevated Plasma Cystathionine level indicate?

Elevated levels of Plasma Cystathionine may be associated with: Vitamin B6 (Pyridoxal-5-Phosphate) functional deficiency, Chronic kidney disease (decreased renal clearance), Cystathioninuria (CTH deficiency).

Which routine blood tests include Plasma Cystathionine?

Plasma Cystathionine is commonly measured in panels such as: Transsulfuration Cascade, Vitamin B6 Functional.

Home/Biomarkers/Micronutrients & Vitamins/Cystathionine

Micronutrients & VitaminsTranssulfuration Intermediate

Plasma Cystathionine (Cystathionine)

Thioether intermediate synthesized from homocysteine and serine by vitamin B6-dependent cystathionine beta-synthase (CBS).

Standard Range40 - 250 nmol/L

Optimal Longevity60 - 180 nmol/L

Measurement Unitnmol/L

Organ SystemTranssulfuration Intermediate

Routine Panels:Transsulfuration CascadeVitamin B6 Functional

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:

28 nmol/LOptimal Zone Target338 nmol/L

Optimal Longevity Zone(120 nmol/L)

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

Standard Reference Interval

40 - 250 nmol/L

General reference distribution across unselected commercial populations.

Optimal Longevity Target

60 - 180 nmol/L

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

Cleaved by cystathionine gamma-lyase (CTH / CSE) into cysteine and alpha-ketobutyrate; accumulates when B6 is deficient or renal clearance is impaired.

Differential Diagnosis

Elevated Levels (Cystathionine High)

•Vitamin B6 (Pyridoxal-5-Phosphate) functional deficiency
•Chronic kidney disease (decreased renal clearance)
•Cystathioninuria (CTH deficiency)

Low Levels (Cystathionine Low)

•Optimal transsulfuration flux to cysteine and glutathione
•Normal B6 sufficiency

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

At the molecular level, Plasma Cystathionine (Cystathionine) plays an essential physiological role in transsulfuration intermediate. 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

Sensitive functional biomarker for vitamin B6 (P5P) deficiency and primary screening marker for mild cystathionine beta-synthase heterozygosity.

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 Cystathionine
Targeted organ system imaging or functional dynamic testing related to transsulfuration intermediate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Plasma Cystathionine - The New England Journal of Medicine (2021). PMID: 34190124
[2]Cystathionine Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901

Common Panels:Transsulfuration CascadeVitamin B6 Functional

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 Cystathionine (Cystathionine) 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 Sarcosine (N-Methylglycine) (Sarcosine)Metabolic & Glycemic Control NextSerum Alpha-1-Acid Glycoprotein (AGP / Orosomucoid)Immunology & Longevity Clocks

Plasma Cystathionine (Cystathionine)

Thioether intermediate synthesized from homocysteine and serine by vitamin B6-dependent cystathionine beta-synthase (CBS).

Standard Range40 - 250 nmol/L

Optimal Longevity60 - 180 nmol/L

Measurement Unitnmol/L

Organ SystemTranssulfuration Intermediate

Routine Panels:Transsulfuration CascadeVitamin B6 Functional

Standard vs. Optimal Reference Rangesnmol/L

Interactive Range Analyzer

Unit: nmol/L

Test Value:

nmol/L

Presets:

28 nmol/LOptimal Zone Target338 nmol/L

Optimal Longevity Zone(120 nmol/L)

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

Standard Reference Interval

40 - 250 nmol/L

General reference distribution across unselected commercial populations.

Optimal Longevity Target

60 - 180 nmol/L

Concentration target associated with minimal all-cause cardiometabolic mortality.

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways

Longevity Risk Architecture & Epidemiology

Sensitive functional biomarker for vitamin B6 (P5P) deficiency and primary screening marker for mild cystathionine beta-synthase heterozygosity.

Pre-Analytical Caveats & Diagnostic Workup

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Confirmatory testing and secondary biomarker quantification for Cystathionine
Targeted organ system imaging or functional dynamic testing related to transsulfuration intermediate
Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)

Clinical Citations & Primary Literature (2)

[1]Clinical Reference and Molecular Physiology of Plasma Cystathionine - The New England Journal of Medicine (2021). PMID: 34190124
[2]Cystathionine Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901

Standard vs. Optimal Reference Rangesnmol/L

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (Cystathionine High)

Low Levels (Cystathionine Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Micronutrients & Vitamins Biomarkers

Standard vs. Optimal Reference Rangesnmol/L

Molecular Mechanism & Clinical Purpose

Differential Diagnosis

Elevated Levels (Cystathionine High)

Low Levels (Cystathionine Low)

Technical Reference & Deep Dive

Pre-Analytical Considerations:

Reflexive Testing Protocol:

Associated Longevity Guides & Clinical Calculators

Related Micronutrients & Vitamins Biomarkers