Health column: A medicine that started as an aphrodisiac

Your testosterone levels fall steadily in late adulthood in women and men. This contributes to some signs of ageing, such as fragile bones, a loss of muscle performance, changes to sleep and even some cognitive skills. So could taking testosterone make you younger?

This is an ancient quest, the search for a magical elixir of youth!

Over a century ago a new aphrodisiac fashion began for men, with injections of testicular extracts from goats, dogs, or guineapigs. Animal testicular tissue was sometimes transplanted into the scrotum, in private clinics.

Attempts to graft testicular tissues into racehorses were encouraged outside the UK. For a short while ’Monkey gland’ treatments were recommended by some British football coaches. Players from Wolverhampton Wanderers famously alleged they were injected with a testicular preparation in the 1930s. Similar preparations were popular among Scottish footballers at the time, although ‘treatments’ were usually collected from cattle (not primates) and probably contained very little testosterone. These procedures became less popular as it became obvious that they did not cause rejuvenation and were not particularly potent.

Testosterone is a steroid hormone manufactured from cholesterol. Most is made in the testicles and ovaries, under the regulation of the hypothalamus in the brain. A young man makes 6-7mg of testosterone a day. This is about five to 10 times higher than an average woman.

Dr Colin Michie, Deputy Head of the University of Central Lancashire School of Medicine based in West Cumbria (Image: UCLAN)

Exercise, stress, or sexual activity increase testosterone levels in all of us. Testosterone has many effects, working in concert with other hormones in the endocrine system. It is anabolic or building, causing height gain in adolescence.

It masculinises too, starting in the fetus, regulating genital development, skin and sweat changes, hair growth and changes in the vocal cords and larynx. These all take place in a sequence during puberty, changing brain functions too, including our attitudes to one another and to sex. Testosterone influences mood and energy levels; it helps construct the brain’s neural networks throughout life.

Purified testosterone has been tested as a medication - trials continue. Many British Hospitals and primary care staff are involved in them. The most common testosterone prescription today is for men with very low testosterone levels, or hypogonadism, seen as a result of age or cytotoxic treatments.

These treatments are safe and improve mobility and brain function. In rare diseases of children, such as delayed puberty or short stature, testosterone can restore normality. For patients suffering bone marrow failure, severe weight loss, burns or some cancers, testosterone again promotes recovery. The hormone is prescribed to develop male secondary sex characteristics in transgender clinics. This year skin patches that deliver testosterone are being tested to improve management of the female menopause.

In the non-medical world, temptations to take hormone treatments to build sporting performance are growing.

Physical training, exercises and careful coaching improve muscle strength, stamina, and muscle mass.

‘Andro’ (androstenedione), ‘T’ (testosterone) and some related hormones can do this too. Their use is banned by global anti-doping authorities.

A young athlete in a gym using testosterone can develop testicular failure, requiring lifelong supplements. It is an effective male contraceptive stopping sperm production. Testosterone abuse can cause kidney and liver damage, acne, breast enlargement and balding. It makes the blood thicker, damaging blood lipids and blood pressure. All in all, a risky approach to improving one’s physique!

Who we are depends greatly on our testosterone – our heights, our emotions, our wellbeing, our ability to regrow nerves in the brain. Prescriptions of testosterone for our older citizens to treat fragility are possible, but these are not exactly an ambrosia of youth!