Blood Testing Services

If you are struggling to access blood tests, we can help.

Testing options

Blood tests are an important part of your treatment plan. The three ways to arrange these are with your Doctor, through a private service or with a home Testing Kit. Requests for these can be arranged through our easy to use order form.

Testing at a Clinic

GenderGP works with a large blood testing service with over 170 clinics around the UK – including the South West, Wales, Northern Ireland and Scotland.

There is more information about these options below.

Once you have identified your nearest clinic, place your order through GenderGP and you will receive an email with details of the Booking Centre at the Pathology Service. You can then call them to arrange an appointment at a convenient time.

As with all blood tests, there is a chance that the sample can fail, however, having your sample taken by a professional phlebotomist and processed on site, greatly reduces that risk.

Results will be returned to GenderGP within three working days.

Testing through your local health service

We can send a letter to your doctor to request that they arrange the tests for you. The benefits of this are that, unless local charges apply, there will be no cost. Your doctor will be sent all the relevant information including what tests you require and how to return the results via our Confidential Information Transfer system. A link to this will also be provided.

You will also receive a copy of this letter for your records.

Please note that we will contact you once we have received and reviewed the blood test results.

How do blood testing kits work?


You will need to do these tests “fasting” i.e. nothing to eat from 9pm the night before doing the test. Then do the test in the morning and post back the same day.

Please try to make sure the tests are carried out at the appropriate time depending on your medication:

Sustanon: Immediately before the next injection

Nebido: Immediately before the next injection

Testosterone gel: At any time

Oestrogen gel: At any time

Oestrogen tablets: At any time

Oestrogen patches: At any time

Blockers: At any time

Please make sure that tests are carried out in the morning and posted back the same day.

If you use gel, make sure your fingers are gel-free for at least 48 hours before the test otherwise you may get an abnormally high test result.

Please follow the instructions given in the pack as closely as you can. However, for additional help – when you get to step two try bathing your hand in some warm water before pricking your finger, to encourage the blood well into the fingertips. You can also take a warm shower or do some gentle exercise beforehand to encourage a good flow, as well as making sure you are well hydrated. Let gravity help by standing up to take your sample. If the blood flow stops, wipe the area with a clean tissue. If it still does not flow use a spare lancet and prick another finger.

You may receive more than one sample tube – you will need to fill all tubes to the second line. You may find it better to do one from one finger and the other from another, this limits the chance of damage to the cells. There is an excellent instruction video at the bottom of this page.

Make sure you keep the form in the grey pre-paid envelope and send it with your sample to our laboratory in London. They will then process the sample and send us the results.

The details on the form must match the details on the tube label or the lab will not process the sample.


It is very important you only post the sample back between Monday and Wednesday.

Although the lab operates 24/7, the Royal Mail doesn’t and the sample may become unusable if it sits untested for more than a day. If you post the sample back between Thursday and Sunday, the sample is likely to spoil and we will have to charge for a retest.

Most samples are processed without a problem, but there are three common things that can go wrong. The laboratory will still charge for processing the sample, and we will need to charge you for a retest.


  • ‘Sample haemolysed’ – this can happen when you squeeze your finger too hard to get the blood out, and the blood cells are damaged on the way out. Be gentle when squeezing your finger to avoid this.  It can also happen if you shake the tube too hard to mix it.
  • ‘Sample clotted’ – if the blood is allowed to clot in the tube before it is mixed with the liquid in the tube. Gently invert the tube to mix the blood.
  • ‘Insufficient sample’ – always make sure you fill the blood to the line.

Please watch this video as it will really help you to make the most out of your test: