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Science & Reference Ranges

Last updated: 24 June 2026

1. Science-Based Health Dashboard

twyn is built on a foundation of scientific transparency and data sovereignty. We believe that users (and their AI agents) must have full clarity regarding how their health data is evaluated.

Unlike conventional wellness apps that use arbitrary scoring systems, twyn evaluates your blood biomarkers using two distinct, evidence-based reference frameworks:

  • Standard Clinical Reference Ranges — established by major diagnostic institutes (such as Mayo Clinic Laboratories, Quest Diagnostics, and LabCorp) to identify and rule out clinical pathology and disease.
  • Optimal Longevity Targets — drawn from aggressive preventive guidelines, namely Peter Attia’s Outlive and Bryan Johnson’s Blueprint, designed to optimize physiological resilience and healthspan.

2. Reference Range Resolution Hierarchy

Every biomarker result on twyn resolves its reference bounds deterministically using the following hierarchy of specificity:

  1. Lab-Provided Range (Quest/LabCorp/etc.) — If your uploaded lab PDF or manually entered reading contains an explicit reference range, twyn prioritizes it first. This ensures that your values are compared against the exact assay methodology, reagents, and calibration used by the laboratory performing the test.
  2. Global Clinical Fallback — If no lab-provided range is available, twyn falls back to standard clinical reference ranges (Mayo Clinic, AHA, ADA) matched to your biological sex and age.
  3. Longevity Target Overlay — Separately, where a marker has an aggressive preventive target (e.g. ApoB < 60 mg/dL, HbA1c < 5.4%), twyn renders it as an aspirational overlay on the chart. These longevity targets are informational only and do not change your clinical status: a value that is clinically normal but above its longevity target is still shown as clinically normal, not flagged. They mark where to aim for proactive optimization, without alarming you against an intentionally strict goal.

3. Detailed Biomarker References & Citations

Metabolic & Glycemic Panel

  • HbA1c — Clinical Normal: < 5.7% (American Diabetes Association). Longevity Target: < 5.4% (Peter Attia, Outlive).
  • Fasting Glucose — Clinical Normal: 70–99 mg/dL (American Diabetes Association).
  • Fasting Insulin — Clinical Normal: < 25 µIU/mL. Longevity Target: < 5 µIU/mL for optimal insulin sensitivity and prevention of subclinical metabolic dysfunction.

Lipids & Cardiovascular Panel

  • ApoB (Apolipoprotein B) — Clinical Normal: < 100 mg/dL (AHA/ACC multi-society guidelines). Longevity Target: < 60 mg/dL (Peter Attia, Outlive) for aggressive cardiovascular prevention.
  • Lp(a) (Lipoprotein a) — Clinical Normal: < 30 mg/dL (AHA/ACC). Longevity Target: < 30 mg/dL (highly genetically determined; evaluated as optimal, borderline, or risk).
  • LDL Cholesterol — Clinical Normal: < 100 mg/dL (AHA).
  • HDL Cholesterol — Clinical Normal: > 40 mg/dL (Male), > 50 mg/dL (Female) (AHA).
  • Triglycerides — Clinical Normal: < 150 mg/dL (AHA).

Liver & Metabolic Function

  • ALT (Alanine Aminotransferase) — Clinical Normal: 7–55 U/L (Male), 7–45 U/L (Female) (Mayo Clinic Laboratories).
  • AST (Aspartate Aminotransferase) — Clinical Normal: 8–48 U/L (Male), 8–43 U/L (Female) (Mayo Clinic Laboratories).
  • Albumin — Clinical Normal: 3.5–5.0 g/dL (Mayo Clinic Laboratories).
  • Bilirubin Total — Clinical Normal: 0.1–1.2 mg/dL (Mayo Clinic Laboratories).
  • GGT (Gamma-Glutamyl Transferase) — Clinical Normal: 8–61 U/L (Male), 5–36 U/L (Female) (Mayo Clinic Laboratories).

Kidney & Renal Health

  • Creatinine — Clinical Normal: 0.74–1.35 mg/dL (Male), 0.59–1.04 mg/dL (Female) (Mayo Clinic Laboratories).
  • BUN (Blood Urea Nitrogen) — Clinical Normal: 7–20 mg/dL (Mayo Clinic Laboratories).
  • eGFR (Glomerular Filtration Rate) — Clinical Normal: > 60 mL/min/1.73m² (National Kidney Foundation; values 60–89 are not pathological without other markers of kidney damage).
  • Uric Acid — Clinical Normal: 3.5–7.2 mg/dL (Male), 2.6–6.0 mg/dL (Female) (Mayo Clinic Laboratories).

Thyroid Panel

  • TSH (Thyroid Stimulating Hormone) — Clinical Normal: 0.3–4.2 mIU/L (Mayo Clinic Laboratories).
  • Free T4 — Clinical Normal: 0.8–1.8 ng/dL (Mayo Clinic Laboratories).
  • Free T3 — Clinical Normal: 2.3–4.2 pg/mL (Mayo Clinic Laboratories).

Hormones

  • SHBG (Sex Hormone-Binding Globulin) — Clinical Normal: 10–57 nmol/L (Male), 18–144 nmol/L (Female) (Mayo Clinic Laboratories).

Hematology & Complete Blood Count (CBC)

  • Hemoglobin — Clinical Normal: 13.8–17.2 g/dL (Male), 12.1–15.1 g/dL (Female) (Mayo Clinic).
  • Hematocrit — Clinical Normal: 40.7%–50.3% (Male), 36.1%–44.3% (Female) (Mayo Clinic).
  • WBC (White Blood Cells) — Clinical Normal: 3.5–10.5 K/uL (Mayo Clinic).
  • Platelets — Clinical Normal: 150–450 K/uL (Mayo Clinic).
  • Lymphocytes % — Clinical Normal: 20%–40% (Mayo Clinic).
  • Mean Corpuscular Volume (MCV) — Clinical Normal: 80–100 fL (Mayo Clinic).
  • Red Cell Distribution Width (RDW) — Clinical Normal: 11.5%–14.5% (Mayo Clinic).
  • RBC (Red Blood Cells) — Clinical Normal: 4.35–5.65 M/uL (Male), 3.92–5.13 M/uL (Female) (Mayo Clinic).

Vitamins & Minerals

  • Vitamin D (25-OH) — Clinical Normal: 30–100 ng/mL (Endocrine Society). Longevity Target: 40–60 ng/mL (optimal balance for bone mineral density and immunological homeostasis).
  • Vitamin B12 — Clinical Normal: 200–900 pg/mL (Mayo Clinic).
  • Folate — Clinical Normal: 3.4–20.0 ng/mL (Mayo Clinic Laboratories).
  • Magnesium — Clinical Normal: 1.7–2.3 mg/dL (Mayo Clinic Laboratories).

4. Disclaimer

The standard clinical ranges and longevity targets provided on twyn are for informational and educational purposes only. twyn is not a licensed medical provider and does not give medical advice. Reference ranges should always be interpreted in consultation with a qualified medical professional, taking into account individual medical histories, symptoms, and clinical contexts.