In the UK, you can get a testosterone blood test through your GP on the NHS if you have symptoms, or privately through a clinic or testing service. Whichever route you choose, the sample should be taken in the morning, ideally after fasting, and a low result should be repeated before anyone makes a diagnosis (BSSM 2023).
Key takeaways
- A GP can arrange a testosterone test if your symptoms suggest low testosterone. Diagnosis is based on symptoms plus blood tests (NHS).
- Blood should be taken between 7am and 11am, ideally fasting, and measured on at least two occasions, preferably 4 weeks apart (BSSM 2023).
- A sugary drink (75g of glucose) has been shown to lower testosterone by 25%, and fasting levels can be up to 30% higher (BSSM 2023).
- UK guidance treats a total testosterone below 12 nmol/L, with symptoms, as usually needing further action (BSSM 2023).
Can you get a testosterone test on the NHS?
Yes. If you have symptoms such as low sex drive, erection problems or fewer morning erections, speak to your GP. The NHS says a diagnosis of low testosterone later in life (late-onset hypogonadism) can usually be made from your symptoms and blood test results. If the tests show a deficiency, you may be referred to an endocrinologist, a specialist in hormone problems (NHS).
An NHS test is free at the point of use, but it's based on clinical need. If you're weighing up whether to ask, our free testosterone symptom checker takes two minutes and helps you describe what you're noticing. Our guide to low testosterone symptoms explains which signs are most telling.
NHS vs private testosterone tests
| NHS (via your GP) | Private | |
|---|---|---|
| Cost | Free at the point of use | You pay; prices and what's included vary |
| Who decides | Your GP, based on symptoms | You choose to test, ideally with clinician input |
| Sample | Blood test, usually at a surgery or hospital | Clinic blood draw or a home finger-prick kit |
| What's measured | Usually total testosterone first, with more tests if needed | Varies by package; check what's included |
| Interpretation | Your GP, with referral if needed | Check that a clinician reviews and explains your results |
Whichever route you use, check that the test fits UK guidance: a morning sample, a reliable method, and a repeat test if the first is low (BSSM 2023).
How to prepare for a testosterone test
Testosterone levels are usually highest in the morning and fall after that (Society for Endocrinology). Food also lowers them. British Society for Sexual Medicine (BSSM) guidance recommends (BSSM 2023):
- have your blood taken between 7am and 11am
- fast beforehand if you can
- expect a second test, preferably about 4 weeks later, to confirm a low result
It also helps to tell the clinician about any medicines, supplements or anabolic steroid use, as these can affect your result.
What is a free testosterone test?
People mean two different things by "free testosterone test".
A test that costs nothing. That's an NHS test arranged by your GP when your symptoms suggest it's needed (NHS).
A test of "free" testosterone. Most testosterone in your blood is bound to proteins, including one called SHBG (sex hormone-binding globulin). The unbound part is called free testosterone. It's usually calculated from your total testosterone and SHBG. BSSM guidance suggests checking SHBG and calculating free testosterone when total testosterone is borderline or low-normal (BSSM 2023).
Understanding your testosterone result
Here's how current UK guidance uses the numbers. These apply to morning samples, repeated, in men with symptoms, not to a single reading (BSSM 2023).
| Result | What BSSM guidance says |
|---|---|
| Total testosterone below 12 nmol/L | Usually needs further action. LH and FSH should be checked to find the cause |
| Total testosterone 8–12 nmol/L (borderline or low-normal) | Check SHBG and calculate free testosterone |
| Free testosterone below 225 pmol/L | Supports a diagnosis of deficiency when symptoms are present |
| Both LH and FSH low | Prolactin should also be measured |
Your lab may print a different "normal range". That's why results need interpreting by a clinician, alongside your symptoms and health.
Is there a "dangerously low" testosterone level?
This is one of the most searched questions on the subject, and the honest answer is that it is the wrong frame. There is no threshold below which testosterone becomes acutely dangerous in the way that, say, a very low blood sugar is.
What a very low result does mean is that the cause needs finding. UK guidance treats total testosterone below 12 nmol/L as warranting further action, with LH and FSH checked to work out where the problem originates (BSSM 2023). A markedly low reading alongside low LH and FSH points towards the pituitary rather than the testes, and prolactin should then be measured — occasionally that picture uncovers a pituitary problem that matters a great deal and has nothing to do with testosterone itself.
So the risk attached to a very low result is not the number. It is leaving the reason uninvestigated, and the longer-term effects of sustained deficiency on bone density, muscle mass and mood.
Two caveats that change how any single figure should be read. Acute illness suppresses testosterone, so a test taken during or just after illness can read low and recover on its own. And a single result never stands alone — diagnosis requires at least two morning samples alongside symptoms.
How to test your testosterone levels
There are three practical routes.
Through your GP. Free, and appropriate if you have symptoms. Ask for a morning sample. If the first is low, a repeat plus LH, FSH and SHBG is the usual next step.
A private venous test. A phlebotomist takes blood from your arm, usually before 11am. This is the most reliable option and the one to choose if you intend to act on the result.
A home finger-prick kit. Convenient, widely sold, and the same caveats apply as to any finger-prick sample: more prone to insufficient volume or damage in transit. The bigger limitation is specific to testosterone — the result depends heavily on when you took it. A kit posted off after a sample collected at 4pm will under-read, and no laboratory can correct for that.
If you use a home kit, collect the sample before 11am, ideally between 7am and 10am, and follow the fasting instructions supplied with it. Our guide to private blood tests in the UK covers what panels generally cost and how venous and finger-prick sampling differ.
What the test is called
If you are booking one yourself, the marker is usually listed as total testosterone. A fuller men's hormone panel adds SHBG (sex hormone binding globulin), from which free testosterone is calculated, plus LH and FSH. Asking for "a testosterone test" will normally get you total testosterone only, which is the right first step but may not be the whole answer if the result is borderline.
Reading the result
Three things matter more than the number itself: that the sample was taken in the morning, that it has been repeated, and that SHBG was measured if the total sits in the borderline 8–12 nmol/L band. A laboratory's printed "normal range" is a population range, not a personal target — which is why the same figure can be unremarkable in one man and worth pursuing in another with symptoms.
Testosterone treatment on the NHS
If a specialist confirms a hormone deficiency, treatment may be offered on the NHS (NHS). This is sometimes called testosterone replacement therapy, or TRT. Whether it's right for you depends on your symptoms, repeated blood results, your overall health and whether you want children, since treatment can affect fertility. Treatment options, including medicines and lifestyle changes, are discussed with your clinician.
Please don't get testosterone or anabolic steroids from gyms, websites or other unregulated sources. Anabolic steroids are class C medicines, and misuse can cause a reduced sperm count and infertility (NHS).
Renvo can help. Our men's health service assesses your symptoms, arranges the right blood tests at the right time of day, and explains what your results mean. testosterone assessment
When to see a GP
See a GP if you have a lower sex drive, erection problems, or symptoms that are affecting your quality of life (NHS). Low mood, poor sleep and low energy often have other causes, such as stress, diet, alcohol or smoking, and a GP can look at the whole picture. Lifestyle changes can also help; see our guide on how to increase testosterone naturally.
If low mood is part of the picture and you ever feel unable to keep yourself safe, call 999, call NHS 111 and choose the mental health option, or call Samaritans free on 116 123 (NHS).
For what private testing costs more broadly, and how to check whether you can get the same test free first, see our guide to private blood tests in the UK.
Honest FAQs
Can I get a testosterone test on the NHS?
Yes. A GP can arrange a blood test if your symptoms suggest low testosterone, and may refer you to an endocrinologist if a deficiency is found (NHS).
What time of day should a testosterone test be done?
Between 7am and 11am, ideally after fasting, because levels are higher in the morning and food lowers them. A low result should be repeated on another occasion (BSSM 2023).
What is a normal testosterone level for a man?
UK guidance uses 12 nmol/L as a key threshold: repeated morning results below this, with symptoms, usually need further action (BSSM 2023). Lab ranges vary, so ask a clinician to interpret yours.
Are home finger-prick testosterone tests reliable?
They can be a starting point. BSSM guidance says testosterone should be measured with a reliable method on at least two occasions, so a low home result should be confirmed with a morning blood test and reviewed by a clinician (BSSM 2023).
Can I get testosterone treatment on the NHS?
Yes, if a specialist confirms a hormone deficiency. You'll usually need symptoms plus repeated low blood tests first (NHS; BSSM 2023).
This article is general information, not medical advice. Always speak to a qualified clinician about your own symptoms.
