Testicular Cancer and Testosterone: What Happens to Your Hormones After Treatment

The lump was small enough that he nearly ignored it. He found it in the shower, a firm, painless bump on the side of his right testicle, and spent two weeks telling himself it was nothing. When he finally saw his GP, he was sent for an ultrasound within days. A week later the testicle was removed, and the surgeon told him the words every young man in that chair wants to hear: caught early, very good outlook.

What nobody explained properly was the question that kept him awake once the fear had faded. With one testicle gone, would he still make enough testosterone? Would treatment change his sex drive, his energy, his chances of having children?

For most men the answer is reassuring. But not for all of them, and the ones who do run into hormone trouble often go years without anyone checking. Here is what actually happens to testosterone before, during and after testicular cancer treatment, and what to ask for at your follow-up appointments.

A cancer of young men, with a very high cure rate

Testicular cancer is uncommon overall, but it hits young men hardest. In the UK there are around 2,400 new cases a year, and in the US the American Cancer Society estimates just under 10,000. It is the most common cancer in young men, typically diagnosed between about 15 and 35, and the average age at diagnosis in the US is about 33.

It is also one of the most curable cancers there is. Around 95% of men are alive five years after diagnosis, and even when it has spread, modern chemotherapy cures the large majority. That success is exactly why the long-term effects matter: most men diagnosed today will live for another 40 or 50 years with whatever treatment leaves behind.

Almost all testicular cancers are germ cell tumours, which grow from the cells that would normally become sperm. They come in two main groups, seminomas and non-seminomas, and the type and stage decide whether surgery alone is enough or whether chemotherapy or radiotherapy follow.

Who is at higher risk

• An undescended testicle at birth, even if it was corrected in childhood
• A father or brother who has had testicular cancer
• A previous testicular cancer in the other testicle
• Some conditions affecting testicular development, including Klinefelter syndrome

Most men who get it have none of these, which is why checking yourself matters more than worrying about risk factors.

Where testosterone comes from, and why one testicle is usually enough

Testosterone is made by Leydig cells, which sit in the tissue between the tubes that produce sperm. They work under instruction from the pituitary gland in the brain, which sends out luteinising hormone (LH). When testosterone runs low, the pituitary sends more LH; when it is high, it sends less.

That feedback loop is the reason a single healthy testicle can usually keep testosterone in the normal range. When one is removed, the brain simply pushes the remaining one harder. Many men notice no change at all.

The catch is the word healthy. Research going back decades shows that men with testicular germ cell tumours often have weaker testicular function to begin with, including in the testicle that does not have the tumour. Scientists group these problems, along with undescended testes and poor sperm quality, under the term testicular dysgenesis syndrome. It means some men start treatment with less reserve than they realise.

Compensated Leydig cell failure: the result that looks normal

This is the pattern most worth understanding. Your testosterone comes back within the normal range, so the report says normal. But your LH is raised, sometimes well above the reference range.

In plain terms, your remaining testicle is only keeping up because your brain is shouting at it. Doctors call this compensated Leydig cell insufficiency. Some men with this pattern feel completely well. Others have symptoms of low testosterone even though the number looks fine, and studies of survivors suggest that this group is more likely to slip into true deficiency over time. If you only ever look at testosterone, you miss it. This is one reason an early morning blood test after testicular cancer should include LH as well.

How each treatment affects your hormones

Surgery (orchidectomy)

Removing the affected testicle through a cut in the groin is the first treatment for almost everyone. On its own, it usually has a modest effect on testosterone, and most men with a healthy remaining testicle stay in range. You will normally be offered a silicone prosthesis at the same operation, which many men find worth having, and it can also be fitted later.

If both testicles have to be removed, which is rare, the body can no longer make meaningful testosterone and lifelong testosterone replacement is needed.

Chemotherapy

Most chemotherapy for testicular cancer is based on cisplatin, often given as a combination called BEP. It is very effective, and it is also tough on the testicle that remains. Large studies of survivors, including long-term follow-up from Denmark, Norway and the UK, consistently find that low testosterone and raised LH are more common after chemotherapy than after surgery alone, and that the risk climbs with the number of cycles. Men who need more intensive or repeated treatment carry the highest risk.

Chemotherapy also stops sperm production for a time. For many men it returns within one to three years, but not for everyone, which is why sperm banking matters (more on that below).

Radiotherapy

Radiotherapy is now used far less often than it once was, mainly for some seminomas. The remaining testicle is shielded, but some scattered radiation can still reach it, and it can affect sperm production more than testosterone. A single dose of the chemotherapy drug carboplatin has replaced radiotherapy for many men with early seminoma.

Surveillance

Many men with early-stage disease are offered active surveillance after surgery: regular scans and blood tests instead of further treatment straight away. Hormonally, this is the gentlest path, because the remaining testicle is spared chemotherapy unless the cancer comes back.

What low testosterone feels like after cancer

The symptoms are the same as low testosterone from any cause, which is part of the problem. They overlap heavily with the effects of having cancer at all.

• Tiredness that does not lift months after treatment has finished
• A lower sex drive, or erections that are weaker or less frequent
• Low mood, irritability or poor concentration
• Losing muscle and gaining fat around the middle, even with the same habits
• Hot flushes or sweats, particularly after both testicles have been removed

It is easy for you, and for a busy clinic, to put all of this down to the after-effects of chemotherapy or the stress of the diagnosis. Sometimes that is right. But it is worth ruling out a hormone cause with a proper blood test rather than assuming. Our guide to the signs of low testosterone men ignore covers the subtler symptoms.

Why it matters beyond how you feel

Cisplatin survivors have a higher long-term risk of high blood pressure, raised cholesterol, weight gain around the middle and, in time, heart disease, compared with men treated by surgery alone. Researchers think low testosterone is one of several factors behind this, alongside direct effects of chemotherapy on blood vessels.

That is why good follow-up after testicular cancer is not only about checking the cancer has not returned. It should also keep an eye on your weight, blood pressure, cholesterol and blood sugar. Low testosterone also affects bone health, so men who stay deficient for years should have this considered too.

Fertility: bank before you start

Most men treated for testicular cancer go on to father children, many without any help. But because chemotherapy and radiotherapy can stop sperm production, sometimes permanently, you should be offered the chance to bank sperm before any treatment that could affect fertility, ideally before surgery as well. If nobody mentions it, ask. It is far easier to store samples beforehand than to deal with infertility later.

There is a second reason this matters. If you later need testosterone therapy, it switches off sperm production while you are on it. Our article on TRT and fertility explains why, and what can be done instead if you are still trying for a family.

Is testosterone therapy safe after testicular cancer?

This is one of the most common worries, and the answer is broadly reassuring. Unlike prostate cancer, testicular germ cell tumours are not driven by testosterone. Major guidelines, including those of the European Association of Urology, support offering testosterone replacement to survivors who have symptoms and a confirmed low level.

The usual rules still apply. Testosterone should be measured on at least two early morning samples before starting, alongside LH, and you should be monitored for blood count, PSA if you are older, and symptoms. Treatment is normally coordinated with your oncology team, particularly in the first years of follow-up.

For reference, UK specialist guidance treats a total testosterone below 12 nmol/L (about 350 ng/dL) as possibly low, and below 8 nmol/L (about 230 ng/dL) as usually low enough to consider treatment when symptoms fit. If you are not sure what your numbers mean, our guide on how to read blood test results walks through it.

A two-minute check that saves lives

Most testicular cancers are found by men themselves. Once a month, ideally after a warm shower when the scrotum is relaxed, roll each testicle gently between your thumb and fingers. You are getting to know what is normal for you, so you notice change.

See a doctor if you find:

• A lump or swelling, even if it is painless
• A testicle that feels heavier or firmer than usual
• A dull ache in the scrotum, groin or lower tummy
• A difference in size or feel that is new

Some tumours make the pregnancy hormone hCG, which can trigger breast tissue growth in men. Unexplained, new breast swelling is worth reporting too. Sudden severe pain in a testicle is different: that can be torsion, which is an emergency, so go to A&E or call 999 in the UK, or 911 in the US.

What to ask at your follow-up

• Can my testosterone and LH be checked on an early morning sample?
• Was sperm stored, and how long is it kept?
• Should my blood pressure, cholesterol and blood sugar be monitored?
• If my testosterone is low, who will manage replacement, my oncologist, my GP or an endocrinologist?

The bottom line

Losing a testicle to cancer does not mean losing your testosterone. Most men keep normal levels, thanks to the remaining testicle and the brain's feedback loop. But a meaningful minority, especially after chemotherapy, end up with low or only just compensated testosterone, and the symptoms are easy to blame on everything else.

The fix is simple: ask for testosterone and LH to be measured properly, keep an eye on your heart health, and treat a confirmed deficiency like any other. You have done the hard part by surviving the cancer. Do not let a missed blood test take the shine off the decades that follow.

Common questions

Will I still make testosterone with one testicle?

Usually, yes. The brain increases its signal to the remaining testicle, and most men stay in the normal range. A minority, more often after chemotherapy, develop low testosterone or a raised LH that shows the remaining testicle is under strain.

Does testicular cancer cause low testosterone before treatment?

It can. Many men with testicular germ cell tumours have reduced testicular function even before surgery, including in the testicle without the tumour. Some tumours also produce hCG, which can disturb hormone levels.

Does chemotherapy permanently lower testosterone?

Not for most men, but the risk of long-term low testosterone is higher after cisplatin-based chemotherapy than after surgery alone, and it rises with the number of cycles.

Can I take testosterone after testicular cancer?

Yes, if you have symptoms and a confirmed low level. Testicular germ cell tumours are not driven by testosterone, and guidelines support replacement for survivors who need it. It does stop sperm production while you take it.

Can I have children after testicular cancer?

Most men do. Sperm production often recovers within one to three years after chemotherapy, but not always, so bank sperm before treatment if you can.

Sources: American Cancer Society, Key statistics for testicular cancer (2026) · Cancer Research UK, Testicular cancer statistics · Skakkebaek NE et al., Testicular dysgenesis syndrome: an increasingly common developmental disorder with environmental aspects, Hum Reprod 2001;16(5):972-8 · Huddart RA et al., Fertility, gonadal and sexual function in survivors of testicular cancer, Br J Cancer 2005;93(2):200-7 · Haugnes HS et al., Cardiovascular risk factors and morbidity in long-term survivors of testicular cancer, J Clin Oncol 2010;28(30):4649-57 · European Association of Urology, Guidelines on Testicular Cancer and on Sexual and Reproductive Health · Educational only, not medical advice.

Keep reading: What causes low testosterone? · Will TRT make you infertile? · Sperm count: what lowers it · Why are my testicles shrinking? · TRT side effects · Low testosterone red flags