Essential Blood Tests

During hormone therapy, regular blood tests are required to monitor hormone levels, ensure treatment efficacy, and identify any potential side effects or complications.

These guidelines are for the minimum recommended blood test requirements. You can also choose to have more frequent blood tests, or have more comprehensive tests for better understanding of your health.

Pre-Therapy Tests

Gender-Affirming Medication	Required Tests	Optional Testing
Spironolactone	Potassium level Blood pressure measurements	Baseline hormones Full Blood Count Liver Kidney Lipids Diabetes
Cyproterone	Liver enzyme levels (e.g., ALT, AST)	Baseline hormones Full Blood Count Kidney Lipids Diabetes
Hormones and other blockers / antiandrogens	None	Testosterone Estradiol Total testosterone SGBH Full Blood Count Kidney Lipids Diabetes

Monitoring Blood Tests for Hormone Therapy

Gender-Affirming Medication	Required Tests	Frequency
Estrogen & Spironolactone	Testosterone Estradiol Potassium levels Blood pressure measurements	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Estrogen & Cyproterone	Testosterone Estradiol Liver enzyme levels (e.g., ALT, AST)	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Estrogen & Finasteride	Testosterone Estradiol	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Estrogen & GnRHa Blocker	Estradiol	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Estrogen alone	Testosterone Estradiol	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Testosterone alone	Testosterone Estradiol Full Blood Count (including Haematocrit)	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Testosterone & GnRHa Blocker	Testosterone Full Blood Count (including Haematocrit)	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
GnRHa Blocker Alone	None	None
Finasteride antiandrogen alone	None Testosterone optional	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.
Spironolactone antiandrogen alone	Potassium Testosterone optional	Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks.

Why do I need these tests?

Potassium Levels must be monitored on medications like Spironolactone as they can affect your body’s electrolyte balance. High potassium levels can lead to muscle weakness and irregular heart rhythms.
Blood Pressure Measurements ensures blood pressure remains within a safe range when you take medications that affect blood pressure, like Spironolactone.
Liver Enzyme Levels can be increased by medications like Cyproterone. High liver enzyme levels can lead to liver damage.
Hormone Level Checks ensure that your hormone therapy is achieving the desired effects while minimising potential risks. If the levels are too low, you won't see the changes you want. Higher levels won't speed up the changes, but do increase the risk of side effects.
Opposite Hormone Levels are checked to make sure that non-GnRHa hormone blockers are effectively suppressing the targeted hormones or if dose adjustments need to be made.

Blood Test Frequency

We recommend that you have blood tests every three months for your first year on hormone therapy. This is to monitor your hormone levels, side effects, and overall health.

Once you have been stable on your medication for a year, we usually recommend only testing once a year.

If you are on a high dose or make a change to your medication, we recommend that you continue monitoring your blood results every three months for at least a year.

You also need to get blood tests done in the following scenarios:

You want to start either cyproterone or spironolactone
You want to increase the dosage of your current medication

See the Pre-Therapy Tests table for reference.

Order Your At-Home Finger Prick Test Through the GenderGP Blood Test Portal Now (Available for Members and Non-Members)

To use the finger prick test, you need to be 16 or older and not taking spironolactone. Vitall, the service provider, will send your blood test results directly to your email address.

If you’re taking spironolactone, you’ll need an intravenous blood sample. You can get this through an online blood test service of your choosing, through your GP if they’re willing to help, or at a private clinic/hospital.

If you need a Blood Test Referral Letter to advise your GP or healthcare provider, you can purchase one through the Treatment Recommendation form for £20 or order it separately here. The letter explains why you need blood tests and which ones you’ll need to get.

When you have your results, please submit them in the Treatment Recommendation form for analysis.