Methodology
What Helios reasons from, and how much of it is settled
Helios compares your labs against reference intervals. Those intervals are the whole premise of the tool, so they are published here in full — including the ones that no clinician has signed off on. This page is generated directly from the engine's range table, so it cannot quietly fall out of date with what the software actually does.
Review coverage
Every biomarker Helios can evaluate, numeric and qualitative.
A licensed clinician has read and signed off on the interval.
No clinician has signed these off. Most have a published source behind them; some are genuinely contested.
62 of the 90 reference ranges in Helios have not been signed off by a clinician. Of those, 47 have a citable published source but no clinical sign-off, and 15 are flagged as unsettled — contested, age-dependent, derived from other values, or with no source on record at all. We publish this because a tool that implied all 90 were settled would be lying to you. Findings that rest on an unsettled range are marked as such inside the product, not hidden.
What the three review states mean
A licensed clinician has read this interval and signed off on it.
A published source backs this interval, but no clinician has signed it off. Not the same as reviewed.
The interval is contested, age-dependent, derived, or has no source on record. Treat it as unsettled.
These are not shades of the same thing. "Evidence-established" means a paper or guideline supports the interval — it does not mean a doctor looked at it in the context of this tool. We keep the two separate on purpose.
Two bands per marker: standard vs optimal
Every numeric marker carries two intervals, and the difference between them matters.
- Standard band
- The conventional laboratory "normal" — the range that covers most of the general population. Falling outside it is what a typical lab report flags. It describes what is common, which is not the same as what is healthy: it is derived from a population that includes plenty of unwell people.
- Optimal band
- The tighter target used in longevity and preventive practice — where the evidence suggests risk is lowest, rather than merely where most people sit. This is the band Helios flags against, which is why it will surface things your lab report called normal.
The honest caveat: optimal bands are inherently less settled than standard ones. Many rest on observational association rather than on trials showing that moving a number produces a better outcome. Each marker below carries a direction telling you which side is the concern — higher, lower, or both extremes.
Evidence tiers on recommendations
Anything Helios suggests carries a tier describing how strong the evidence behind it actually is. Tiers are never upgraded to make a suggestion look better supported than it is.
- Tier A — trials and guidelines
- Backed by randomised controlled trials or established clinical guidelines. The strongest thing we can say.
- Tier B — cohort and mechanistic
- Backed by observational cohort studies or a plausible biological mechanism. Suggestive, not proven — these show association, and association is not causation.
- Tier C — emerging and anecdotal
- Early research, small studies, or practitioner experience. Included for completeness and explicitly labelled. Treat with real scepticism.
What this engine will not do
- It does not diagnose. An out-of-range marker is an observation to discuss with a clinician, never a condition.
- It does not prescribe. Every medication, hormone, peptide, and therapy it surfaces carries dosing ranges, an evidence tier, and a requires-licensed-clinician flag. It is information to bring to an appointment, not an instruction to follow.
- The safety gate runs before ranking, always. Interventions blocked on safety grounds — interactions, contraindications, your stated conditions — never enter the recommendation list at all. They are set aside as withheld for safety, and you can see that they were withheld.
- It does not invent your data. Values parsed out of an uploaded lab PDF are proposals until you confirm them. Nothing extracted by OCR or a language model is trusted automatically, and uncertain values are surfaced as uncertain rather than guessed.
- It does not send your health data to third parties. Queries to external research databases carry only topic strings such as "testosterone replacement outcomes" — never your identity, your labs, or your symptoms.
Every reference range in the engine
All 90 markers, grouped by body system. Filter by review state to see exactly what is signed and what is not. Markers flagged needs review show the reason their interval is still contested.
Cardiovascular (9)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
ApoB mg/dL | <90 | <70 | Higher is worse | Clinician-reviewed |
Cholesterol/HDL ratio ratio | <5 | <3.5 | Higher is worse | Evidence-established Risk rises >5 (Framingham-derived ratio). |
HDL-C mg/dL | Male40–90 Female50–90 | Male50–90 Female60–90 | Lower is worse | Clinician-reviewed |
LDL-C mg/dL | <100 | <70 | Higher is worse | Clinician-reviewed |
Lp(a) nmol/L | <125 | <75 | Higher is worse | Clinician-reviewed |
Non-HDL cholesterol mg/dL | <130 | <100 | Higher is worse | Evidence-established Non-HDL goals — ACC/AHA / NLA. |
Total cholesterol mg/dL | 125–200 | 150–180 | Both extremes are worse | Evidence-established Desirable <200 mg/dL — NCEP ATP-III. |
Triglycerides mg/dL | <150 | <80 | Higher is worse | Clinician-reviewed |
VLDL mg/dL | <30 | <20 | Higher is worse | Evidence-established Calculated VLDL ~2–30 mg/dL (derived from triglycerides). |
Hematologic (20)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
Basophils % % | <2 | <1 | Higher is worse | Evidence-established WBC differential reference intervals (reference labs). |
Basophils (abs) x10^3/uL | <0.2 | <0.1 | Higher is worse | Evidence-established Absolute basophil count reference interval (reference labs). |
Eosinophils % % | <5 | <3 | Higher is worse | Evidence-established WBC differential reference intervals (reference labs). |
Eosinophils (abs) x10^3/uL | <0.5 | <0.3 | Higher is worse | Evidence-established Absolute eosinophil count reference interval (reference labs). |
Hematocrit % | Male38.3–50 Female35.5–44.9 | Male40–48 Female37–44 | Both extremes are worse | Clinician-reviewed |
Hemoglobin g/dL | Male13.5–17.5 Female12–15.5 | Male14–16.5 Female12.5–14.5 | Both extremes are worse | Evidence-established WHO anemia cutoffs M<13 / F<12 g/dL; reference labs. |
Lymphocytes % % | 20–45 | 25–40 | Both extremes are worse | Evidence-established WBC differential reference intervals (reference labs). |
Lymphocytes (abs) x10^3/uL | 1–3.5 | 1.4–3 | Both extremes are worse | Evidence-established Absolute lymphocyte count reference interval (reference labs). |
MCH pg | 27–33 | 28–32 | Both extremes are worse | Evidence-established Reference-lab adult interval ~27–33 pg. |
MCHC g/dL | 32–36 | 33–35 | Both extremes are worse | Evidence-established Reference-lab adult interval ~32–36 g/dL. |
MCV fL | 80–100 | 85–92 | Both extremes are worse | Evidence-established Reference-lab adult interval ~80–100 fL. |
Monocytes % % | 2–10 | 3–8 | Both extremes are worse | Evidence-established WBC differential reference intervals (reference labs). |
Monocytes (abs) x10^3/uL | 0.1–0.9 | 0.2–0.7 | Both extremes are worse | Evidence-established Absolute monocyte count reference interval (reference labs). |
Neutrophils % % | 40–75 | 45–65 | Both extremes are worse | Evidence-established WBC differential reference intervals (reference labs). |
Neutrophils (abs) x10^3/uL | 1.8–7.5 | 2–6 | Both extremes are worse | Evidence-established Absolute neutrophil count reference interval (reference labs). |
PSA ng/mL | <6.5age-stratified | <3 | Higher is worse | Clinician-reviewed |
Platelets x10^3/uL | 150–400 | 200–350 | Both extremes are worse | Evidence-established Reference-lab adult interval ~150–400 x10^3/uL. |
RBC x10^6/uL | Male4.5–5.9 Female4–5.2 | Male4.7–5.5 Female4.2–4.9 | Both extremes are worse | Evidence-established Reference-lab adult intervals (StatPearls NBK604207). |
RDW % | <14.5 | <13 | Higher is worse | Evidence-established ~11.5–15%; high RDW associates with mortality (PMC5640961). |
WBC x10^3/uL | 3.5–10.5 | 4–8 | Both extremes are worse | Evidence-established Reference-lab adult interval ~4.5–11.0 x10^3/uL. |
Hormonal (6)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
DHEA-S ug/dL | Male40–290age-stratified Female15–160age-stratified | Male120–250 Female70–150 | Lower is worse | Clinician-reviewed |
Estradiol pg/mL | Male10–40 Female30–400 | Male20–30 Female50–200 | Both extremes are worse | Clinician-reviewed |
Free testosterone pg/mL | Male50–200 Female1–8.5 | Male120–200 Female3–7 | Lower is worse | Clinician-reviewed |
IGF-1 ng/mL | 65–220age-stratified | 100–180 | Both extremes are worse | Clinician-reviewed |
SHBG nmol/L | 20–60 | 25–45 | Both extremes are worse | Clinician-reviewed |
Total testosterone ng/dL | Male300–1000 Female15–70 | Male600–900 Female30–60 | Lower is worse | Clinician-reviewed |
Inflammation (9)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
ALT U/L | Male<44 Female<32 | Male<25 Female<20 | Higher is worse | Evidence-established Healthy ULN ~29–33 (M) / 19–25 (F) U/L — ACG 2017 (PubMed 27995906). |
AST U/L | Male<40 Female<32 | Male<25 Female<22 | Higher is worse | Evidence-established Lab ULN ~35–40 U/L (Mayo Proceedings LFT review). |
Alkaline phosphatase U/L | 40–129 | 50–95 | Both extremes are worse | Evidence-established ~30–120 U/L — Cleveland Clinic LFT. |
Bilirubin (total) mg/dL | 0.2–1.2 | 0.3–1 | Both extremes are worse | Needs review 'Lower is better' optimal is likely inverted — higher bilirubin associates with antioxidant/protective effects. See docs/RANGE_EVIDENCE.md (fix #6). |
ESR mm/hr | Male<20 Female<30 | Male<10 Female<15 | Higher is worse | Needs review Age-dependent (Westergren; Miller upper bound ≈ age/2). Our fixed band is wide and not age-adjusted — no authoritative endorsement. See docs/RANGE_EVIDENCE.md §C. |
GGT U/L | Male<65 Female<45 | Male<20 Female<16 | Higher is worse | Clinician-reviewed |
Homocysteine umol/L | <15 | <8 | Higher is worse | Clinician-reviewed |
Rheumatoid factor IU/mL | <14 | <10 | Higher is worse | Evidence-established Normal <14(–20) IU/mL — Cleveland Clinic. |
hs-CRP mg/L | <3 | <1 | Higher is worse | Clinician-reviewed |
Metabolic (15)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
Albumin g/dL | 3.5–5 | 4.3–5 | Both extremes are worse | Evidence-established 3.5–5.0 g/dL — Medscape lab values. |
Albumin/Globulin ratio ratio | 1–2.5 | 1.2–2.2 | Both extremes are worse | Needs review Derived albumin/globulin ratio; no authoritative optimal interval. See docs/RANGE_EVIDENCE.md. |
Bicarbonate (CO2) mmol/L | 22–30 | 24–28 | Both extremes are worse | Evidence-established 22–29 mmol/L — Mayo BMP reference. |
Calcium mg/dL | 8.6–10.3 | 9.2–10 | Both extremes are worse | Evidence-established 8.4–10.6 mg/dL — Medscape lab values. |
Chloride mmol/L | 98–107 | 100–106 | Both extremes are worse | Evidence-established 98–107 mmol/L — Mayo reference. |
Fasting glucose mg/dL | 70–99 | 75–90 | Higher is worse | Clinician-reviewed |
Fasting insulin uIU/mL | 2–19 | 2–6 | Higher is worse | Clinician-reviewed |
Globulin g/dL | 2–3.9 | 2.4–3.2 | Both extremes are worse | Needs review Calculated (total protein − albumin); upper bound wide with no authoritative optimal interval. See docs/RANGE_EVIDENCE.md. |
HOMA-IR index | <2.5 | <1.5 | Higher is worse | Clinician-reviewed |
HbA1c % | 4–5.6 | 4.5–5.3 | Both extremes are worse | Clinician-reviewed |
Phosphate mg/dL | 2.5–4.5 | 3–4 | Both extremes are worse | Evidence-established 2.5–4.5 mg/dL — Medscape lab values. |
Potassium mmol/L | 3.5–5.1 | 4–4.8 | Both extremes are worse | Evidence-established 3.6–5.2 mmol/L — Mayo reference. |
Sodium mmol/L | 135–145 | 137–142 | Both extremes are worse | Evidence-established 135–145 mmol/L — Mayo BMP reference. |
Total protein g/dL | 6–8.3 | 6.5–7.8 | Both extremes are worse | Evidence-established 6.3–8.3 g/dL — Medscape lab values. |
Uric acid mg/dL | Male3.4–7 Female2.4–6 | Male3.5–5.5 Female3–5 | Both extremes are worse | Evidence-established Reference intervals; treat-to-target <6.0 mg/dL — ACR 2020 gout (PubMed 32391934). |
Micronutrient (8)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
Ferritin ng/mL | Male30–400 Female15–200 | Male50–150 Female40–120 | Both extremes are worse | Clinician-reviewed |
Folate ng/mL | 3–20 | 10–20 | Lower is worse | Evidence-established Deficiency <3–4 ng/mL (NHANES-derived). |
Iron ug/dL | Male65–175 Female50–170 | Male90–150 Female70–140 | Both extremes are worse | Evidence-established ~50–175 µg/dL adult reference (Medscape). |
RBC Magnesium mg/dL | 4–6.4 | 5–6.4 | Lower is worse | Clinician-reviewed |
TIBC ug/dL | 250–450 | 250–400 | Both extremes are worse | Evidence-established ~250–370(–450) µg/dL (Medscape). |
Transferrin saturation % | 20–50 | 25–40 | Both extremes are worse | Evidence-established 20–50% (<20 deficient, >50 overload) — Medscape. |
Vitamin B12 pg/mL | 200–900 | 500–900 | Lower is worse | Clinician-reviewed |
Vitamin D (25-OH) ng/mL | 30–100 | 50–80 | Both extremes are worse | Clinician-reviewed |
Oncologic-Screening (4)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
AFP ng/mL | <8 | <5 | Higher is worse | Evidence-established Adult reference <8 ng/mL (lab-variable). |
CA 125 U/mL | <35 | <30 | Higher is worse | Evidence-established Standard cutoff <35 U/mL. |
CA 19-9 U/mL | <37 | <30 | Higher is worse | Evidence-established Standard manufacturer cutoff <37 U/mL. |
CEA ng/mL | <3 | <2.5 | Higher is worse | Evidence-established Nonsmoker <3.0 ng/mL — Cleveland Clinic. |
Renal (15)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
BUN mg/dL | 7–20 | 10–18 | Both extremes are worse | Evidence-established 6–21 mg/dL — Medscape lab values. |
Creatinine mg/dL | Male0.7–1.3 Female0.6–1.1 | Male0.8–1.1 Female0.6–1 | Both extremes are worse | Evidence-established M 0.74–1.35 / F 0.59–1.04 mg/dL — Medscape lab values. |
Urine RBC qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine WBC qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine bilirubin qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine blood qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine glucose qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine ketones qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine leukocyte esterase qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine nitrite qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine pH pH | 4.5–8 | 6–7 | Both extremes are worse | Evidence-established 4.5–8.0 — AAFP urinalysis. |
Urine protein qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Urine specific gravity SG | 1.005–1.03 | 1.01–1.025 | Both extremes are worse | Evidence-established 1.005–1.030 — Cleveland Clinic. |
Urine urobilinogen qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
eGFR mL/min/1.73m2 | 45–120age-stratified | 60–120 | Lower is worse | Clinician-reviewed |
Serology (1)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
HIV 1/2 antibody qualitative | Qualitative (present / absent) — no numeric band | — | Both extremes are worse | Needs review No source on record for this interval. |
Thyroid (3)
| Marker | Standard band | Optimal band | Direction | Review state |
|---|---|---|---|---|
Free T3 pg/mL | 2.3–4.2 | 3.2–4.2 | Lower is worse | Clinician-reviewed |
Free T4 ng/dL | 0.8–1.8 | 1.1–1.6 | Both extremes are worse | Clinician-reviewed |
TSH mIU/L | 0.4–4.5 | 0.8–2 | Both extremes are worse | Clinician-reviewed |