Home StoriesPart of Inside Our Books

The castration effect

In this extract from Gavin Francis’s book ‘Shapeshifters’, the author explores the effects of lowering testosterone on the male body, from the drastic surgery performed on eunuchs and castrati to the place of hormone reduction in modern prostate cancer treatment.

Words by Gavin Francisphotography by Benjamin Gilbertaverage reading time 12 minutes

  • Book extract
Photograph of an illustration of a naked man where the body of the man has been cut out and lifted above the background. Where the man's genitals should be there is a black hole with the torn edges folded forwards.

The university library at my medical school was shared with students of veterinary medicine. Sometimes I’d find myself at a desk opposite one of the vet students; we’d glance at one another’s textbooks with curiosity, occasionally open at the same subjects – haematology, say, or orthopaedic surgery. It was reassuring to see how much common ground there was between medicine for humans and medicine for animals.

One day I was revising prostate cancer: the appearance of its malignant cells under a microscope, the stages of its spread, the radiotherapy, brachytherapy (embedding of radioactive pellets into the tumour), and standard chemotherapies used to treat it. In health, the prostate gland stores semen and mature sperm; it has strong muscular walls that squeeze during ejaculation.

Exposure to a lifetime of testosterone increases the growth of the gland as well as its susceptibility to cancers. Many treatments for prostate cancer work by blocking testosterone’s generation within the testicles – with no testosterone, the growth of the tumour slows.

“All that for prostate cancer?” asked one of the vet students, glancing over at my notes.

“Sure,” I said. “What do you guys do to treat it?” “One word,” he laughed, “castration!”

As a boy I’d see farmers castrating spring lambs in the fields near my home. They’d take a tiny rubber ‘O’, the diameter of its hole almost as wide as the rubber was thick, and with a pair of special pliers spring it over the lamb’s scrotum. The rubber squeezed off the blood supply to the testes, and a few weeks later they’d drop off. The first time I saw farmers gelding lambs I asked one of them, “Doesn’t it hurt?”

He shrugged. “It’s better this than the old way,” he replied. “A century ago, shepherds used their teeth.” After an afternoon spent gelding, the men’s beards would be clotted with blood.

Gelding animals takes testosterone out of their development, making them less aggressive and more biddable, but also bigger (sex hormones accelerate the closure of the growth plates of bones, so without testosterone, animals’ bones grow longer before fusing). Low testosterone levels also encourage the accumulation of fat. You can leave castrated animals grazing alongside females without fear they’ll reproduce.

Agricultural societies have used it since long before written records: castrated oxen take a yoke more easily, and will pull a plough with less whipping. Castrated dogs are simpler to train, and will more readily round up the castrated sheep put out to fatten in the fields.  

Photograph of an illustration of a naked man where the body of the man has been cut out and lifted above the background. Where the man's genitals should be there is a black hole with the torn edges folded forwards.

The usefulness of eunuchs

Early Assyrian and Chinese civilisations transposed this knowledge to humans: boys born in poverty would be castrated and sent to work under the yoke of the state in the imperial household. (In China, both penis and testicles were removed – these ‘three treasures’ were pickled in a jar, brought out for special occasions, and buried with the eunuch.) Eunuchs were often taller, sometimes stronger than average, and were frequently employed as the core of an imperial guard. They could work in the imperial harem without fear that they’d cuckold the emperor.

When Alexander the Great conquered Persia he was struck by the utility of such eunuch slaves, and adopted the custom – eunuchs were also considered sexually desirable. The Romans copied it from the Greeks: the Emperor Nero had a eunuch called Sporus (whom he dressed as a woman, and married) and the Emperor Domitian had a favourite eunuch called Earinus.

More: The perceived dangers of male masturbation.

Photograph of a photograph of a naked man where the body of the man has been cut out and lifted above the background. Where the man's genitals should be there is a black hole with the torn edges folded forwards.

There’s usually an element of voyeurism in the Roman accounts, a curiosity about ambiguous gender and genitalia that’s still visible in media coverage of the phenomenon today. Eunuchs were high-class slaves, the most expensive in the market; in losing testicles they were believed to have lost family loyalty and to have become faithful only to their masters and to the empire.

Around the time that Christianity began to spread into the Roman Empire there was already a cult of a eunuch god called Attis, who was celebrated in springtime and believed to have died then been resurrected after three days. His priests committed self-castration in honour of a fertility goddess, and they did it on the hill in Rome where Vatican City sits now.

In China, both penis and testicles were removed – these ‘three treasures’ were pickled in a jar, brought out for special occasions, and buried with the eunuch.

The practice survived the Christianisation of the Roman Empire: one of the early Church fathers, Origen, is famous for committing self-castration. Castration continued in Byzantium (where gelded boys were trained as choristers) and into the 20th-century Russian Orthodox church, where the skoptsy sect encouraged self-castration as late as the 1920s.

St Paul’s advice that women should keep quiet in church was taken to its logical conclusion during the Italian Renaissance: God’s glory was sung in soprano by castrated men from the mid-1500s. The Jesuit Tommaso Tamburini, active in the early 17th century, sanctioned castration only “provided there is no mortal danger to life and that it is not done without the boy’s consent”.

How much choice they had in the matter is hard to assess, though reports throughout the 17th and 18th centuries describe boys ‘pleading’ for the honour of being castrated, to bring both prestige and financial security to their families. The complex, high-pitched melodies for which castrati were most in demand by the Vatican were those sung around Easter week – the same time of year that the priests of Attis celebrated castration.

The Vatican didn’t ban the castration of boys for its choirs until the late 19th century, and the last castrato of the Sistine Chapel, Alessandro Moreschi, died in 1922. But 20 years before he died, with his voice already fading in quality, he made a series of recordings for the Gramophone and Typewriter Company, which would become His Master’s Voice or HMV. You can find the recordings online, Moreschi’s voice a wavering, ghostly soprano that makes every song an elegy.

Photograph of an illustration of a naked man where the body of the man has been cut out and lifted above the background. Where the man's genitals should be there is a black hole with the torn edges folded forwards.

A case of prostate cancer

The comedian Billy Connolly once joked that he’d reached an age when doctors had become uninterested in his balls and had begun showing greater interest in his rectum. The median age for testicular cancer is around 34; for prostate cancer it’s nearer 72. To have your prostate gland checked manually you have to lie on one side, knees pulled up to your chest, while a doctor puts a gloved finger in through your anus – the size and consistency of the prostate can be assessed through the thin bowel wall.

Prostate cancer is common: among my local patient population of almost 4,000, there are several new diagnoses a year. Alex Sinclair was one of them: a 62-year-old builder, muscular and stoical, bald, with a beard so dense and black it was as if the lower half of his face was eclipsed.

He told me he was divorced, and hinted at a dynamic sex life; his children had long ago grown up and moved away. He came to clinic wearing his overalls. “I used to get up once or twice a night to pee,” he told me, “but now it can be five or six times. I wake up exhausted.” There were times he found himself standing at the toilet for a full minute before urine began to trickle out. “I prefer not to see doctors,” he said. “But I couldn’t put it off any more.”

We worked through a questionnaire called the ‘International Prostate Symptom Score’, which asks for a rating of one to five across a series of questions, from how often you have had the sense that you haven’t emptied your bladder to how often you have to strain to initiate urine flow: Alex scored an impressive 22.

I took a blood sample from his arm to examine levels of a substance specific to the prostate – this ‘PSA test’ varies broadly with prostate size, and can on occasion flag up cancer. I asked if I could do a rectal examination up on the couch. “I’ve heard about these,” he said with resignation, standing up to unzip his overalls. “If you must.”

Alex’s prostate was huge, jutting back from its position under the bladder and indenting his rectum. On one side of the crease down the middle of the gland I felt a firmer, discrete lump, like a pebble lodged in tarmac.

“Well, that’s why you’ve been struggling,” I told him. “Your prostate is so large, urine can hardly squeeze through it.” Alex stood up and started pulling up his overalls. “I’d like you to see one of the specialists,” I added, then caught and held his eye. “They’ll want to check tiny pieces of the gland under a microscope.”

His actions slowed as he took in this information. Then he asked carefully: “How do they get the pieces out?”

“They’ll pass a very fine needle in through your anus, and through the bowel wall.” I was hoping to reassure, but wondered if perhaps I was making his anxiety worse. “Your prostate gets bigger the longer it’s been exposed to the testosterone in your body – so the longer you’ve lived, the bigger your prostate grows. You’re not alone – it’s quite common to start getting problems around your age.”

“Is it the same thing as cancer?” he asked, pulling up his zip and reaching for his hat.

I waited a couple of moments, until again his gaze swung back towards me. “Just as every man’s prostate grows the longer he’s lived, they say every man gets prostate cancer if he lives long enough. But in most men it grows slowly, and never causes bother.”

“How will I know if it’s going to cause bother with me?”

Photograph of an illustration of two men where the body of the men have been cut out and lifted above the background. Where one of the men's genitals should be there is a black hole with the torn edges folded forwards.

Living with hormone treatment

The urologists confirmed it: Alex had prostate cancer. What’s more, it had spread, and so removing his prostate gland to eliminate the tumour wasn’t an option. The first step to improving his quality of life was to widen the urinary passage through the prostate, or “bore it out” as Alex put it (builders have a useful store of analogies when thinking about the body and its failings).

I had assisted in these operations as a junior doctor: a patient was laid anaesthetised on their back, legs in stirrups, while a narrow instrument with a camera inside it was advanced down through the penis and into the bladder. It was always an amazement to watch the procedure, the camera exploring an unseen, barely credible world of pink tunnels and embankments, delicately veined and whorled with contours.

Once into the prostate, a wire loop emerged from the instrument, which, when heated up by an electric current, could simultaneously peel away and cauterise the tissue that had been blocking the urine’s flow. It took a few days for the bleeding to settle down – days in which Alex had to stay in hospital with a wide-bore catheter draining the bladder.

Following the procedure Alex’s urine was flowing, but his cancer was too far advanced to be eliminated. I started him on injections to shut down the production of testosterone in the testes, as well as hormone blockers. Plans were made for radiotherapy at the local hospital.

I reviewed him a couple of weeks after the first injection. His interest in sex had collapsed, his skin felt hot and dry, his urine heavy and stinging. “I’ve never been much of a worrier,” he told me, “but I’m getting uptight about everything these days. And I can’t watch a film without blubbing like a baby.”

He wanted to continue working, but found his muscles ached after even minimal exercise, and he was losing much of his strength. These were all symptoms that could be put down to the loss of testosterone, rather than to the cancer. “I used to lift four sheets of plasterboard no problem,” he told me, “but I think I’ll be lucky if I can manage two.”

Over subsequent weeks his testicles shrank, and though he didn’t lose the density of his beard, his skin took on a pink, delicate sheen, as if it were becoming more fragile.

“Have you had enough?” I asked him one day, after he’d detailed all the side effects that were troubling him. “Do you want to stop the treatment?”

“Not if it’s doing me good,” he replied. “If it’s keeping down the cancer, for me at least – it’s worth it.”

Alex still attends my clinic every twelve weeks for the injections that wither his testicles but slow the growth of his tumour. A pragmatist by nature, he sees the exchange as a reasonable compromise: “I’m lucky to be here,” he says, as he loosens his belt for the injections, which, for their size, have to be given into the largest muscle in the body – the buttock.

After the initial shock of the treatment his libido returned, slowly, and one day he told me he had a new girlfriend. “Her eyes are wide open,” he said, “she knows I might not be around for ever.” I told him just to let me know if he wanted to try medication for impotence, but he just winked. “No need,” he said, “I’ve just got to use a bit more imagination than I used to.”

Shapeshifters’ is out now.

About the contributors

Photograph of Gavin Francis

Gavin Francis


Dr Gavin Francis has worked across four continents as a surgeon, emergency physician, medical officer with the British Antarctic Survey and latterly as a GP. He’s the author of the Sunday Times-bestselling ‘Adventures in Human Being’ and ‘Recovery’, as well as ‘Shapeshifters’ and ‘Intensive Care’. He also writes for the Guardian, The Times, the London Review of Books and Granta.

Photographic black and white, head and shoulders portrait of Benjamin Gilbert.

Benjamin Gilbert


Ben is a senior photographer for Wellcome. He is happiest when telling stories with his photographs, whether that be the health implications of rural-to-urban migration in India, or the dedication of the workers who power the NHS.