Written by Francesca Steyn, NMC-registered fertility practitioner
A semen analysis tells you what is coming out. A male hormone test for fertility tells you about the system producing it. The two answer different questions, and when a semen result is borderline or unexpected, the hormones are usually where the explanation sits. Here is what each one measures and what a clinician does with it.
What a semen analysis shows, and where it stops
A semen analysis measures volume, sperm concentration, total count, motility and morphology against World Health Organisation (WHO) reference values. NICE (National Institute for Health and Care Excellence) sets these out in its 2026 fertility guideline NG257: 1.4 ml or more of semen, 16 million sperm per ml or more, 39 million or more in total, 42% or more motile, and 4% or more normal forms. Our guide to what counts as a normal sperm count goes through each of those in turn.
That is a good, objective measurement. What it cannot tell you is why. Two men can return an identical borderline result, one because of a hormonal issue that is treatable, the other for a reason that has nothing to do with hormones at all. Nothing in the semen analysis separates them.
It is worth knowing how the NHS pathway handles this. Under NG257, if a first semen analysis is abnormal a repeat confirmatory test is offered, ideally three months later, to allow a full cycle of sperm production to complete (1.17.3 and 1.17.4). For men with two or more abnormal analyses, the guideline recommends a physical examination of the scrotum and testes and says a clinician should consider measuring testosterone and the gonadotrophins, FSH and LH (1.17.5). That is a sensible use of NHS resources. It also means that for most men, hormones sit at least one repeat test and three months down the line.
FSH and LH: the signal from the brain to the testes
Follicle-stimulating hormone (FSH) and luteinising hormone (LH) are made by the pituitary gland. LH tells the testes to produce testosterone. FSH drives sperm production itself. Together they are the instruction; testosterone and sperm are the response.
Reading them alongside testosterone is what makes them useful, because the pattern tells you where a problem sits.
Two patterns, two very different meanings
If testosterone is low and FSH and LH are high, the pituitary is shouting and the testes are not responding. That points to the testes themselves. Clinically this is called primary hypogonadism.
If testosterone is low and FSH and LH are low or normal, the instruction is not being sent properly in the first place. That points upstream, to the pituitary or hypothalamus, and is called secondary hypogonadism. The British Society for Sexual Medicine guideline notes that LH is what differentiates the two.
The distinction matters because it changes what happens next. Secondary hypogonadism can often be treated with medication that restarts the signal. Primary hypogonadism does not respond to that, and the next step there is a specialist referral rather than a prescription.
Total and free testosterone, and why free matters
Most testosterone in your blood is bound to proteins and is not available to do anything. Only the unbound portion, free testosterone, is active.
This is why a total testosterone result on its own can mislead. If the binding protein is high, total testosterone can read as perfectly normal while the free fraction is low. The British Society for Sexual Medicine recommends checking the binding protein when total testosterone is borderline or low to normal, particularly in older or heavier men, and calculating free testosterone from it along with albumin.
That calculation is why the binding protein appears on the panel at all. It is not measured for its own sake.
The rest of the panel, briefly
Sex hormone binding globulin (SHBG) is that binding protein. On its own it tells you little. Paired with total testosterone it is what makes a calculated free testosterone possible.
Albumin is the main protein in your blood, made by the liver. It is not a hormone and it is not there to diagnose anything on its own. Testosterone also binds to albumin, but only loosely, so that portion is still partly available to the body. Free testosterone is calculated from three numbers together: total testosterone, SHBG and albumin. Leave albumin out and the free testosterone figure is less accurate. Albumin can run low during illness or with liver disease, which is one more reason the results are read together by a clinician rather than one at a time.
Prolactin is a pituitary hormone. When it is raised it suppresses the signal to the testes, which lowers LH, FSH and testosterone together. The British Society for Sexual Medicine advises measuring it when LH and FSH come back low, because raised prolactin is one of the recognised reasons for that pattern.
Oestradiol is not only a female hormone. Men convert a portion of their testosterone into it, and a normal amount is required for sperm production to work at all. Too much can suppress it. The balance between testosterone and oestradiol is what clinicians look at rather than either number alone.
Dehydroepiandrosterone sulphate (DHEA sulphate) comes from the adrenal glands rather than the testes. It is the most abundant adrenal steroid, and it shows how much of your overall androgen picture is coming from that source rather than from the testes.
What a fertility practitioner does with both sets of results together
On their own, neither test is a diagnosis. Together they let a fertility practitioner work through a sequence: is sperm production actually reduced, or is this a one-off sample? Is the signal from the pituitary normal, raised or suppressed? Is testosterone genuinely low, or only low-looking because of binding?
From there the picture usually points one of three ways. There is a recognised cause that responds to treatment, there is one that calls for a specialist referral, or the sensible next step is simply to repeat the test in three months. Sperm take roughly three months to produce, which is exactly why NG257 uses that interval, and why a single result is a snapshot rather than a verdict.
How the blood sample is collected at home
You do not need a clinic visit or a vein draw from a phlebotomist. The hormone panel uses a Tasso device, a small collector that sticks to your upper arm. A press of a button releases a lancet that punctures the skin and immediately retracts, and the sample is drawn into a tube. It goes back in prepaid packaging alongside the semen sample.
At Malebox the semen analysis is performed by an andrologist registered with the Health and Care Professions Council (HCPC) against WHO guidelines, results come back within 24 hours of both samples reaching the lab, and an NMC-registered fertility practitioner takes you through the full picture on a 30 minute video call. The sperm test with a consultation is £240, and the version that adds the eight-hormone profile is £320.
What this means in practice
If you have never had a semen analysis, start there. It is the first test in every guideline for a reason, and for many men it is the only one they will need.
If you have had one and the result was borderline or unexpected, hormones are the logical next question rather than repeating the same test and hoping for a different answer.
If you are taking testosterone, or considering it, this matters more than anything else on this page. The British Society for Sexual Medicine is direct about it: in younger men, testosterone therapy lowers LH and FSH and frequently causes infertility after 6 to 12 months. It is reversible in around 60 to 70% of men within 9 to 12 months of stopping, which leaves a meaningful minority in whom it is not, and planning a pregnancy is listed as one of the main reasons not to start. We have gone into this in more detail in does TRT affect fertility.
If you are simply curious about your baseline, both tests together give you a complete starting picture in one go rather than in stages.
Frequently Asked Questions
Do I need a hormone test if my sperm test looked normal?
Usually not. A normal semen analysis means the system is producing what it should. Hormone testing is most useful when a semen result is borderline, abnormal or surprising, or when there are other reasons to ask about testosterone.
What do FSH and LH show about male fertility?
They show whether the pituitary gland is sending the right signal to the testes. Read alongside testosterone, a high FSH and LH with low testosterone points to the testes, while low or normal FSH and LH with low testosterone points to the pituitary.
Does testosterone therapy affect sperm production?
Yes. Testosterone therapy suppresses FSH and LH and commonly causes infertility within 6 to 12 months. It is reversible in around 60 to 70% of men within 9 to 12 months of stopping, so not in everyone.
Why measure free testosterone as well as total?
Most testosterone is bound to proteins and inactive. If binding protein levels are high, total testosterone can look normal while the active free portion is low. Measuring SHBG allows free testosterone to be calculated.
How long do hormone results take?
At Malebox, results are ready within 24 hours of both the semen and blood samples arriving at the lab. They are then explained on a video consultation rather than sent as a number on a page.
A hormone profile is not something every man needs. It is the test that answers the question a semen analysis raises but cannot settle, and if you are at that point, it is worth having both in front of you at the same time.
Francesca Steyn is an NMC-registered fertility practitioner with over 20 years in reproductive health. She has served on the NICE guideline committee and the HFEA legislative reform group.
