Testosterone Blood Test: Normal Levels and What Your Result Means
When to take the test, the ranges that count as low, borderline and normal, and the extra tests that matter if you're on TRT.
Part of the Access Doctor Low Testosterone Guide.
Key fact: A testosterone test should be done before 10am, ideally fasting. Below 8 nmol/L is low, 8 to 12 nmol/L is borderline and above 12 nmol/L is normal (BSSM 2023). One low result should always be repeated.
A testosterone blood test is the only way to know whether your testosterone is low. Getting the timing right matters as much as the test itself, because testosterone changes through the day and after meals. For symptoms and causes, see our guide to low testosterone.
Check Your Testosterone Level
A home finger-prick blood test, taken in the morning and analysed by an accredited UK lab.
Order a Testosterone Blood Test →What the Test Measures
Total testosterone
All the testosterone in your blood. This is the main result used to diagnose low testosterone.
SHBG
Sex hormone-binding globulin, the protein that carries testosterone. High or low SHBG changes how much testosterone your body can use.
Free testosterone
The active portion, usually calculated from total testosterone and SHBG. It helps when total testosterone is borderline.
Other markers
LH, FSH and prolactin show where a problem starts. These are usually arranged by your GP.
When and How to Take the Test
- Before 10am: testosterone peaks in the morning and can be much lower later in the day
- Fasting: eating, especially sugary food, lowers testosterone for a few hours
- When you’re well: illness, a bad night or heavy exercise can lower it temporarily
- Twice: a low or borderline result should be repeated on another morning before a diagnosis is made
- If you work nights: test within about 3 hours of waking from your main sleep, rather than by the clock
Testosterone Levels: What’s Normal?
| Total testosterone | What it means (BSSM 2023) |
|---|---|
| Above 12 nmol/L | Normal. Testosterone treatment isn’t usually needed |
| 8 to 12 nmol/L | Borderline. Free testosterone and symptoms help decide; a trial of treatment may be considered by a specialist |
| Below 8 nmol/L | Low. Usually confirms testosterone deficiency if repeated and you have symptoms |
Your lab report shows its own reference range, which can differ slightly. Some labs report testosterone in ng/dL; 12 nmol/L is about 350 ng/dL.
Other Tests Your GP May Do
If your testosterone is low, your GP will look for a cause. Tests usually include LH and FSH (to tell a testicular problem from a pituitary one), prolactin, a full blood count, PSA, blood sugar (HbA1c), cholesterol and liver tests. Very low testosterone or abnormal pituitary hormones usually mean a referral to an endocrinologist.
Blood Tests If You’re on TRT
Men on testosterone treatment need regular checks of three things:
1
Testosterone level
To check your dose. When to test depends on your gel: see the table below, and follow your prescriber’s advice.
2
Haematocrit (full blood count)
TRT can raise the red blood cell level. Above 0.54, treatment is stopped or reduced until it falls.
3
PSA
A prostate check before treatment, then at about 3 to 6 months and 12 months, and every year after that.
| Your gel | When to take the blood test |
|---|---|
| Testogel (pump or sachets) | In the morning, before you apply that day’s dose |
| Testavan | 2 to 4 hours after applying it |
| Tostran | About 2 hours after applying it |
Read more in TRT side effects and monitoring.
Home test
Testosterone Blood Test
A morning finger-prick test, analysed by a UK lab.
View product →Home test
PSA Blood Test
A prostate (PSA) test for men who've chosen to have one, or are on TRT.
View product →Home Test or GP Test?
| Home finger-prick test | GP blood test | |
|---|---|---|
| Sample | A few drops from your fingertip, posted to a lab | Blood taken from a vein in your arm |
| Good for | A convenient first check, or a check between reviews on TRT | Diagnosis, and finding the cause |
| What’s included | Testosterone (and related markers, depending on the kit) | Testosterone plus LH, FSH, prolactin, blood count, PSA and other tests as needed |
| Limits | Can’t diagnose low testosterone on its own | Needs a morning appointment |
Getting a good finger-prick sample
- Drink water beforehand and warm your hands in warm water for a couple of minutes
- Stand up and let your arm hang down so blood flows to your fingers
- Let the drops fall into the tube; squeezing hard can damage the blood cells, and the lab may not be able to test the sample
- Post it the same day, early in the week, so it isn’t delayed over a weekend
If the lab can’t process a sample, it will tell you, and the test needs repeating.
What to Do With Your Result
- Normal: if you still have symptoms, see your GP; low mood, poor sleep or another condition may be the cause
- Borderline or low: repeat the test on another morning and book a GP appointment with both results
- Very low (well below 8 nmol/L): see your GP soon, as further tests are needed to find the cause
We don’t start testosterone treatment online. Treatment begins with your GP or a specialist, who confirms the diagnosis and looks for a cause. Once you’re established on a gel, we can provide repeat prescriptions.
Already on Testosterone Treatment?
Order your repeat prescription online. A UK pharmacist prescriber checks your treatment and recent blood results. For men already prescribed testosterone only.
Start Low Testosterone Consultation →Frequently Asked Questions
What is a normal testosterone level for a man?
Above 12 nmol/L is normal, 8 to 12 nmol/L is borderline and below 8 nmol/L is low, according to BSSM 2023 guidance. Your lab report shows its own reference range, which may differ slightly.
Why does a testosterone test have to be done in the morning?
Testosterone is highest in the morning and falls through the day, and eating lowers it too. Testing before 10am, ideally fasting, gives a reliable result that can be compared with the standard ranges.
Do I need two testosterone tests?
Yes, if the first is low or borderline. Testosterone varies from day to day, so guidance recommends two morning tests before low testosterone is diagnosed.
What is free testosterone?
Free testosterone is the part not bound to proteins in the blood, which your body can use. It's usually calculated from total testosterone and SHBG, and helps when total testosterone is borderline.
What is SHBG?
Sex hormone-binding globulin is a protein that carries testosterone in the blood. High SHBG can mean less testosterone is available even when the total level looks normal; low SHBG has the opposite effect.
When should I test my testosterone on TRT?
It depends on your gel. Testogel is usually checked in the morning before your dose, Testavan 2 to 4 hours after applying it, and Tostran about 2 hours after. Follow your prescriber's instructions.
Can I test my testosterone at home?
Yes. A finger-prick kit taken before 10am and posted to an accredited lab gives a reliable result. A low result should still be repeated and discussed with your GP.
References
- Hackett G, et al. British Society for Sexual Medicine. British Society for Sexual Medicine guidelines on male adult testosterone deficiency, with statements for practice. World Journal of Men's Health, 2023. bssm.org.uk
- NHS South Yorkshire ICB. Shared care protocol: testosterone for male hypogonadism (Doncaster). December 2025. southyorkshire.icb.nhs.uk
- Electronic Medicines Compendium. Testogel 16.2mg/g gel: Summary of Product Characteristics. medicines.org.uk
- Electronic Medicines Compendium. Testavan 20mg/g transdermal gel: Summary of Product Characteristics. medicines.org.uk
- Electronic Medicines Compendium. Tostran 20mg/g transdermal gel: Summary of Product Characteristics. medicines.org.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Prescription medicines require a consultation before they can be dispensed. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.