Can I drink coffee before a testosterone blood test?

Water is fine. UK guidance recommends a fasting sample for the most reliable result, so it is best to have coffee and breakfast after your test.

What time of day should a free testosterone test be taken?

In the morning, before 11am, when testosterone is at its highest. UK guidance says samples taken later in the day should not be used to diagnose low testosterone, and the same applies to free testosterone.

Do I need a free testosterone test if my total testosterone is normal?

Often not. UK guidance says calculated free testosterone adds little when SHBG is normal, but it can help when SHBG is high or low or total testosterone is borderline.

Free Testosterone Blood Test at Jace Medical

Hormones & fertility

Private blood test

Free Testosterone Blood Test

Measures free testosterone, the active portion not bound to proteins in the blood.

4 biomarkers
Fasting recommended

£49Includes sample collection

Book this test Ask a question

We confirm your appointment and any preparation, such as fasting, before you attend.

What’s included

4 biomarkers in this test.

Fasting recommended before this test

Liver1

Enzymes and proteins that show how well your liver is working.

Albumin

Hormones & fertility3

Reproductive, stress and adrenal hormones.

Sex Hormone Binding Globulin (SHBG)
Testosterone
Free Testosterone

About this test

Is the Free Testosterone Blood Test right for you?

Who it’s for

You have symptoms that can be linked to low testosterone, such as low sex drive, erection problems, low energy, low mood or loss of muscle.
Your total testosterone was borderline and you want to know how much of it is free, or active.
You have a condition that can change SHBG, such as obesity or a thyroid or liver problem, so total testosterone alone may be misleading.
You want to repeat a previous low result, which is needed before low testosterone can be confirmed.

What it can show

Total testosterone is the main measurement. It includes testosterone that is bound to proteins in the blood as well as the small free portion.
Most testosterone is carried by SHBG (sex hormone binding globulin) and albumin, and only a small proportion is free. High or low SHBG changes how much testosterone your body can use.
Free testosterone is calculated from your testosterone, SHBG and albumin results. UK guidance says it is most useful when SHBG is high or low, or when total testosterone is borderline.

What it can’t tell you

Testosterone is highest in the morning and drops after eating and after poor sleep, so results from later in the day can look falsely low.
A single low result needs repeating on another morning before low testosterone can be confirmed.
Short-term illness can lower testosterone, so avoid testing while you are unwell.
Free testosterone is a calculated estimate. When SHBG is normal, it adds little to the total testosterone result.
We provide the test and doctor-reviewed results. Diagnosis, and any decision about starting or changing treatment, is made with your GP, specialist or prescriber.

How it works

From booking to results in three steps.

Step 1
Request your test
Send a booking request online or call us. We confirm your clinic, appointment time and any preparation.
Step 2
Visit the clinic
A short appointment for professional sample collection at Greysteel or Letterkenny. No GP referral needed.
Step 3
Receive your results
Usually within a couple of working days, emailed to you once a doctor has reviewed them.

Common questions

Questions about this test.

Total testosterone measures all the testosterone in your blood, most of which is bound to SHBG and albumin. Free testosterone is the small unbound portion your body can use, and it is calculated from your testosterone, SHBG and albumin.