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Information about blood testing


The information on this page is not a substitute for medical advice. To find out what blood tests you need, you should talk to a qualified medical professional.

Why you should get tested

Regular blood testing is important for two main reasons:

  • To make sure you’re on the right doses. Knowing how your hormone levels compare to “reference ranges” — what doctors think of as a “normal” level of oestrogen or testosterone for a healthy man or woman — will make sure you’re receiving the right dose.

    If your hormone levels are lower than they ought to be, that could mean you’re not getting the changes you want from HRT. Likewise, if your hormone levels are higher than they should be, that could mean you’re on too high a dose, and could be at risk of bad side-effects.

  • To spot any potential problems before they occur. Hormone replacement therapies come with a number of risks and side-effects, including things like:

    • Blood clots
    • Liver and kidney problems
    • Polycythaemia and erythrocytosis
    • Prolactinoma
    • Liver dysfunction
    • Heart disease
    • High blood pressure

    However, regular testing can reduce the risk of many of these things by flagging up any potential issues well before they become a serious problem.

    The exact risks will depend on what you’re taking, your physiology, and your family history, among other factors. For more information about the risks of hormone therapy, you should talk to your GP or an endocrinologist.

What tests you need

Blood tests for people taking oestrogen will usually include things like:

  • Oestradiol
  • Testosterone
  • Prolactin
  • FSH (Follicle Stimulating Hormone)
  • LH (Luteinising Hormone)
  • Liver function
  • Thyroid stimulating hormone
  • Lipid profile
  • Fasting glucose

Blood tests for people taking testosterone will usually include things like:

  • Oestradiol
  • Testosterone
  • Prolactin
  • Haemoglobin
  • Haematocrit
  • Liver function
  • Lipid profile
  • Fasting glucose

Note that these are just representative examples, and the exact tests you need may vary. Many gender clinics have published guidance for GPs about the particular tests needed for people taking hormones, which you can find on the Gender Archive website.

In addition to blood tests, you may also need regular monitoring of things like blood pressure and weight. People taking blockers but not oestrogen or testosterone may need to have bone density monitored.

For more information on what tests are appropriate for you, talk to your GP or an endocrinologist.

Where you can get tested

One way to get a blood test is to ask your GP for one. This will make sure your blood tests are a part of your medical records. You can also ask your GP for a hospital blood test form: this is a form you can take to a hospital phlebotomy department at your convenience, rather than having to keep a particular appointment.

Your GP should be able to offer blood tests even if you’re self-medicating.

Some sexual health clinics may be able to offer blood tests. These clinics will often provide a “drop-in” service where you don’t have to make an appointment, and will be able to keep your records separate from your main NHS record if that’s what you want.

The following clinics offer blood testing for trans people:

Some clinics might provide these tests without necessarily advertising them. To find out exactly what your local clinic can and can’t offer, you can phone up and ask.

Some clinics offer blood tests on a private basis (i.e. you pay for the test yourself) where you attend one of their clinics to have blood taken and tested (for example, clinics operated by Randox Health).

Finally, there are several private companies (for example, MediChecks) which will send you fingerprick tests for you to use at home. These come with a vial that you’ll fill with blood and send off to a lab. This can be a useful option if you can’t get a test through your GP or local clinic, but keep in mind that:

  • You might find it difficult to draw your own blood at home
  • A fingerprick test may be less accurate than a normal venous blood draw test

Dealing with needle phobia

The prospect of getting blood tests done might be particularly difficult if you have a fear of needles. However, there are some practical ways you can deal with this.

  • Guys and St. Thomas’ NHS Foundation Trust have produced a short guide on how to deal with a fear of needles.
  • EMLA cream or a similar local anaesthetic may be useful if you’re worried about pain.
  • If you’re taking any other medication that needs blood monitoring, they should be able to combine the tests so you only need to get your blood taken once.


This page is illustrated using a photograph by Alena Shekhovtcova available at Pexels.

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