How to Read a Telehealth Lab Report Without a Medical Degree
Most telehealth programs hand you a lab PDF with red and green flags and a clinician note that's two sentences long. The actual numbers — the range columns, the units, the units that don't match what your friend's clinic uses — are rarely explained. This is a working primer for reading the labs your telehealth provider orders.
Reference Range vs Optimal Range
Reference ranges on lab reports are derived from the middle 95% of a 'healthy' population sampled by the lab. They are descriptive, not prescriptive: 'within range' means 'common in our sample population,' not 'this is the level your body is best at.' Optimal range, by contrast, is the level associated with the lowest disease risk and best functional outcomes in research literature — often a narrower window inside the reference range.
Total testosterone is the textbook example. The LabCorp reference range for adult men is roughly 264–1000 ng/dL, but symptomatic hypogonadism studies cluster the threshold for treatment around 300–350 ng/dL, and most TRT clinicians target a trough of 500–800 ng/dL on therapy. A '350 ng/dL' result is technically 'normal' but symptomatically often not.
GLP-1 Baseline Labs: What Each Test Catches
| Test | Reference range | What it catches |
|---|---|---|
| HbA1c | 4.0–5.6% | Underlying type 2 diabetes that changes the prescribing decision |
| Fasting glucose | 70–99 mg/dL | Insulin resistance baseline |
| TSH | 0.4–4.5 mIU/L | Thyroid disease (rule out before attributing fatigue to weight) |
| ALT/AST | <35 U/L | Liver function before starting GLP-1 |
| Lipase | 13–60 U/L | Pancreatic baseline (GLP-1s carry a pancreatitis warning) |
| eGFR | >60 mL/min/1.73m² | Kidney function for dose adjustment |
TRT Baseline Labs: The Six Numbers That Matter
- Total testosterone (AM, fasting, two separate draws): the diagnostic threshold.
- Free testosterone (calculated or LC-MS): what's bioavailable to tissue.
- Sex hormone-binding globulin (SHBG): determines how much testosterone is free.
- Estradiol (sensitive assay only): rules out underlying aromatization issues.
- Hematocrit and hemoglobin: TRT raises both; baseline is your reference point.
- PSA (over 40, or with prostate concerns): screens for prostate disease before starting therapy that may stimulate growth.
Numbers Your Clinic Should Flag
A serious telehealth provider should walk through any of these without you having to ask: hematocrit above 52% on TRT (consider blood donation or dose reduction); estradiol above 50 pg/mL on TRT in a symptomatic patient; ALT or AST elevation 2x above normal at any baseline draw; HbA1c above 6.5% (warrants type-2 diabetes workup before starting weight-loss therapy); and TSH above 4.5 mIU/L (subclinical hypothyroidism that may be contributing to weight or fatigue).