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Blood Draws

Lab work is how you tell whether your HRT is actually doing what you think it is. Symptoms lag, and "I feel fine" can coexist with testosterone that's still in cis-male range. This page covers what to order, when to draw, how often to repeat, and where to get the work done.

For interpreting results once you have them, see Hormone Levels.

Why monitor

Three reasons:

  1. Efficacy — confirm estradiol is in target range and testosterone is suppressed. Without numbers, you're titrating blind.
  2. Safety — estrogen affects clotting and lipids; spironolactone affects potassium and kidneys; cyproterone affects the liver and prolactin. Periodic labs catch problems early.
  3. Adjustment — different dose, route, or regimen changes need lab confirmation that the change worked, not just that it felt different.

The Endocrine Society 2017 guideline calls for hormone levels every 3 months in the first year of HRT and every 6–12 months after that, with additional safety panels driven by which drugs are in the regimen.

What to order

Three tiers — the essentials, the standard add-ons most providers also include, and the situational tests that depend on your regimen or symptoms.

Tier 1 — every test

Test What it tells you
Estradiol (E2) Whether your estrogen is in target range (typically 100–200 pg/mL for MtF on HRT)
Total testosterone Whether T is suppressed (target <50 ng/dL)

If you're only going to order two things, order these.

Tier 2 — standard add-ons (most providers include)

Test When to include
Free testosterone or SHBG When total T looks suppressed but androgenic symptoms persist (oral E2 raises SHBG, which can mask high free T)
LH / FSH Useful early on to confirm pituitary suppression; less informative later
Prolactin Endocrine Society recommends periodic checks on estrogen; especially important if on cyproterone (prolactinoma risk)
Comprehensive metabolic panel Liver enzymes (ALT, AST), kidney function (BUN, creatinine), glucose, electrolytes
Lipid panel Estrogens shift cholesterol; baseline + periodic
CBC General health; flags anemia, infection

Tier 3 — situational

Test When to include
Potassium (specifically) If on spironolactone — required at baseline and periodically
Liver function tests (LFTs) If on cyproterone, bicalutamide, or flutamide — required, often more frequent than the standard panel
Progesterone (P4) Only meaningful if you're supplementing it; rectal/vaginal P4 produces dramatically higher serum levels than oral
DHT If you have specific concerns about scalp hair loss, body hair, or acne — most labs don't include it by default; ask explicitly
PSA (prostate-specific antigen) Generally screen in patients over 50 (or earlier with family history)
Bone density (DEXA scan) Long-term, especially if on a GnRH agonist or post-orchiectomy with sub-therapeutic estrogen
Vitamin D, B12 If symptoms of deficiency or risk factors

When to test

Comparative serum estradiol curves over time for oral, sublingual, transdermal patch, and IM routes, with a horizontal MTF target band overlay

Timing matters more than dose for getting interpretable numbers. The biggest variable is route:

Route When serum E2 peaks What to test
Oral / sublingual estradiol ~2–6 hours after dose Test ~midway between doses for an "average," or right before next dose for trough
Transdermal patch / gel Steady-state after 1–2 weeks Any time once steady; drawing during the patch's "wear" period
Estradiol valerate IM Day 2–3 after injection (peak ~400–600 pg/mL with 4–5 mg) Trough (just before next injection) is the most clinically meaningful single number
Estradiol cypionate IM Day 2–4 after injection Trough as above; cypionate's longer duration (14–18 days) gives a broader trough window

Two practical rules:

  1. Always note when you took your last dose when you submit a sample — without that, the result is uninterpretable. A 400 pg/mL E2 four hours after a sublingual is healthy; a 400 pg/mL trough on injectables is high.
  2. Don't change your regimen in the week before a test. If you've just up-dosed, your levels are still moving — wait ~2 weeks for steady state on a stable dose before retesting.

For injectables specifically, recent research (Endocrine Practice 2024 scoping review) found that current dosing guidelines often produce target-exceeding peaks with sub-target troughs — so testing only at peak gives a falsely reassuring picture. Trough is the safer single time-point.

How often

Phase Frequency
Baseline (before starting) Full panel — establishes pre-treatment values
Titration phase (first 6–12 months) Every 3 months per Endocrine Society; some providers do every 6–8 weeks while actively adjusting
Maintenance Every 6–12 months, with safety panels (LFTs, K+, lipids) annually
After any regimen change 2–6 weeks after the change took effect (allow steady state)
Symptom-driven Any time symptoms suggest something is off (mood, libido, fatigue, headache, breast pain)

How to interpret

Lab values aren't directly comparable between labs — each runs its own assay calibration. Interpret your result against your lab's reference range (printed on the report), not against a universal number.

For target ranges relevant to MtF HRT (and the cis male/female reference values), see Hormone Levels.

Where to get tested

Two basic paths:

Through a provider

PCP, endocrinologist, or trans-care telehealth (Plume, FOLX, QueerDoc, GenderGP) writes the order; you go to a Quest or LabCorp draw site (or equivalent in your country); insurance typically covers the labs if your provider is in-network.

Direct-to-consumer (DTC)

For people without a trans-friendly provider, or who want to monitor more frequently than a provider will order. Several services maintain their own physician network to legally order labs in your state, then route the draw to Quest or LabCorp:

The full list with category breakdowns is on the Resources page.

US state-level barriers

DTC labs work because the service provides its own licensed physician to sign your order — but state law varies. In some US states (NY, NJ, RI being the most restrictive), DTC ordering of certain tests is limited or blocked. If a DTC service refuses your order, that's usually why. Some workarounds: mail a sample from a friend in a permissive state, or use a service whose physician network covers your state.

Cost expectations (rough, US, 2026)

A "feminizing HRT panel" through a DTC lab typically runs \(90–\)180 self-pay (E2 + total T + LH/FSH + prolactin + CMP + CBC + lipids). Smaller panels (just E2 + total T) are \(40–\)80. With insurance through a provider it's usually \(0–\)30 copay. UK Medichecks "transgender hormone health" panels are roughly £80–£140. LetsGetChecked international is more expensive ($129+ for a hormone panel).

Sources