Blood Tests — What & When
Why Blood Tests Are Essential
Blood tests are the only reliable way to know if your HRT is working correctly. Without them, you are guessing. Regular testing allows you to:
- Confirm your E2 is in feminising range (100–200 pg/mL)
- Confirm your T is suppressed (< 50 ng/dL)
- Monitor for side effects (liver, kidney, prolactin, lipids)
- Make informed dose adjustments
Before Starting HRT (Baseline)
Get a baseline blood test before taking any hormones
A baseline establishes your natural hormone levels and health markers. Without it, you can't measure how much HRT is changing things.
| Test | Why It Matters |
|---|---|
| E2 (estradiol) | Natural baseline level |
| Total T (testosterone) | Natural baseline level |
| LH, FSH | HPG axis function |
| SHBG | Hormone-binding protein baseline |
| CBC (complete blood count) | Red/white blood cells, platelets |
| Comprehensive metabolic panel | Liver (ALT, AST), kidney (creatinine), electrolytes |
| Lipid panel | Cholesterol, triglycerides |
| Prolactin | Baseline before CPA |
| Blood pressure | Separate from blood test but equally important |
First Year of HRT (Every 3 Months)
| Test | Target | Notes |
|---|---|---|
| E2 | 100–200 pg/mL (367–734 pmol/L) (trough) | Draw blood just before next dose |
| Total T | < 50 ng/dL (< 1.73 nmol/L) | |
| SHBG | < 150 nmol/L | If elevated, consider route change |
| CBC | Normal range | Anaemia monitoring |
| CMP | Normal range | Liver/kidney function |
| Potassium (if on spiro) | Normal range | Check every 3 months in year 1 |
After First Year (Every 6–12 Months)
| Test | Frequency |
|---|---|
| E2, T, SHBG | Every 6 months |
| CBC, CMP | Annually |
| Lipid panel | Annually |
| Prolactin (if on CPA) | Annually |
| Potassium (if on spiro) | Annually (if stable) |
How to Get Blood Tests
With a Prescribing Provider
Your provider will order labs as part of routine care. This is the best option — tests are covered by insurance/public healthcare.
Without a Provider (DIY)
| Method | How It Works | Cost |
|---|---|---|
| Private lab (US) | Order online from LabCorp/Quest via sites like PrivateMDLabs or Jason Health | $50–150 |
| GP request (UK) | Some GPs will order blood tests under a harm reduction agreement even if they won't prescribe | Free (NHS) |
| Walk-in clinic | Some clinics will order tests if you explain you're self-managing HRT | Varies |
| Finger-prick tests | Home test kits for E2, T (less accurate than venous draw) | $30–80 |
Tips for Accurate Results
TEST AT TROUGH — NOT PEAK
For injectable hormones, blood must be drawn immediately before your next dose (trough).
- Estradiol injections: trough = just before next injection (e.g., day 5 or 7)
- Testosterone injections: trough = just before next injection (typically day 7)
Do not test within 48 hours of an injection. Testing at peak gives misleadingly high results and can cause you to lower your dose incorrectly.
| Tip | Why |
|---|---|
| Test at trough | Just before your next dose/application — shows minimum levels |
| Consistent timing | Always test at the same point in your cycle |
| Same lab | Different labs use different assays; consistency matters |
| Morning draw | T levels are highest in the morning; test then for consistency |
| Fast (optional) | Fasting is recommended for lipid panels |
| No biotin | Biotin supplements can falsely alter hormone test results; stop 3–5 days before |
Understanding Your Lab Results
Units Conversion
| Hormone | Common Units | Conversion |
|---|---|---|
| Estradiol (E2) | pg/mL | 1 pg/mL = 3.67 pmol/L |
| Testosterone (T) | ng/dL | 1 ng/dL = 0.0347 nmol/L |
| SHBG | nmol/L | No conversion needed |
What the Numbers Mean
Estradiol (E2)
| Level | Interpretation |
|---|---|
| < 50 pg/mL | Too low; no feminisation |
| 50–100 pg/mL | Low; some effect but likely insufficient |
| 100–200 pg/mL | Target range |
| 200–300 pg/mL | High but acceptable (common with monotherapy) |
| > 300 pg/mL (trough) | Very high; consider reducing dose |
Total Testosterone (T)
| Level | Interpretation |
|---|---|
| > 200 ng/dL | Male range; HRT not working |
| 100–200 ng/dL | Partially suppressed; not enough |
| 50–100 ng/dL | Borderline; some people do well here |
| < 50 ng/dL | Target range |
| < 20 ng/dL | Fully suppressed; acceptable |
Sample Blood Test Tracker
| Date | E2 (pg/mL) | T (ng/dL) | SHBG (nmol/L) | Dose | Notes |
|---|---|---|---|---|---|
| 01/01/26 | 25 | 550 | 30 | Baseline | Pre-HRT |
| 04/01/26 | 80 | 120 | 50 | E2 2mg, Spiro 50mg | Start HRT |
| 07/01/26 | 145 | 35 | 65 | E2 4mg, Spiro 100mg | Good levels |
References
Deutsch MB, ed. (2016). Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People. UCSF Transgender Care. https://transcare.ucsf.edu/guidelines
Hembree WC, et al. (2017). Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons. JCEM. https://academic.oup.com/jcem/article/102/11/3869/4157558