When 56-year-old Chloe Williams had her ovaries removed, she wasn’t prepared to lose her libido. “My sex drive dried up completely; I couldn’t bear the thought of it. Apparently, my ovaries had been producing a bit of testosterone, even though I went through the menopause a few years ago. After the operation, which I had to reduce my risk of cancer, I felt under-powered, tired and not in the least bit interested in sex. My GP offered me testosterone, and I jumped at it.”
She is far from alone; there is growing interest in the role of the hormone in both men and women. And scientists are asking: do falling levels in old age, or after cancer treatment, damage our health? Does testosterone replacement restore vim, vigour and all-round perkiness? And can you have too much of a good thing?
Testosterone is often called the male hormone, but women have it, too. It is made from cholesterol in the gonads (testes in males, ovaries in females) and both sexes also make some in the adrenal glands that sit just above the kidneys. Production in the gonads and adrenals is stimulated by hormones produced in the brain, and testosterone levels fall gradually as you get older, especially in men.
If you suffer from primary hypogonadism, the gonads do not produce testosterone, while in secondary hypogonadism, the hypothalmus or pituitary in the brain do not pump out enough of two other hormones, known as LH (Luteinizing hormone) and FSH (follicle-stimulating hormone), to stimulate the gonads into production.
London endocrinologist Dr Mark Vanderpump is concerned about rising use of the drug in the UK – prescriptions rose by around 90% (from 157,602 to 298,314) between 2000-2010.
“The key is to get a firm diagnosis before committing a person to a treatment for life that isn’t risk-free,” he says. “Every person needs individual, tailored management – there’s not one protocol that fits everyone. It’s important to monitor red blood cell count that increase the risk of thrombosis.”
Williams’s GP prescribed a testosterone gel, even though it is not licensed for use by women. An alternative would have been an HRT preparation that has some testosterone-like effect called tibolone. The Endocrine Society says: “Testosterone should be reserved for post-menopausal women with sexual dysfunction secondary to hypoactive sexual desire, because there is limited data regarding long-term efficacy and safety. Testosterone levels do not predict response, and should not be routinely measured, but monitoring for signs of androgen excess is important.”
Androgen excess – too much testosterone – can cause problems such as excess hair and acne. Williams says her libido did improve after a few days, but she thinks it might have been psychological. “I think my sex drive was low because I was recovering from the impact of surgery and the genetic test that said I was at risk of cancer. I’m not sure how I feel about using a drug that may cause side effects or be ineffective.” Vanderpump says the small doses prescribed to women should be safe.
Adrian Sylvester, 34, went to his GP after he and his partner had been trying for a baby for two years. “I’d been finding it hard to get reliable erections and my sex drive was rubbish. I put it down to tiredness and stress. Then I got so anxious about the whole thing that it put me off sex altogether. My GP organised a sperm test that hardly showed any sperm at all.”
Sylvester had blood tests that showed low levels of testosterone, LH and FSH. An endocrinologist did further tests, but could not find a specific underlying cause. Sylvester was advised to cut out the strong opiate painkillers that he was taking for back pain, changed job and took steps to reduce his stress levels.
But the endocrinologist explained that while prescribing testosterone might help libido, energy levels and muscle bulk, it would not restore sperm production. In fact, it could make it worse, because the brain senses the extra testosterone in the bloodstream and produces even less LH and FSH. Testosterone has been considered as a male contraceptive for this reason. Happily, within three months, Sylvester’s hormone levels and sperm-count improved and although Adrian’s partner isn’t pregnant yet, the chances are that they will be able to conceive naturally in time, but Vanderpump points out that drugs such as opiates and certain illness can temporarily lower testosterone, so repeat measurements are always advised.
Testosterone levels in men peak in their late 20s, declining from around 30. Most experts believe it is an inevitable part of ageing, but say lifestyle changes, such as losing weight and reducing alcohol intake can improve levels and symptoms. Confusingly, blood levels of the hormone may not correlate with symptoms; some men with low testosterone feel fine, while others with levels at the low end of normal feel drained of energy and strength, and improve greatly when given the hormone.
Seven placebo-controlled trials are underway in the US to try to establish what symptoms men with low levels due to age alone might experience, and whether the therapy helps. Findings from the first three showed treatment improves sexual function, but has questionable impact on vitality, mood and depression. And study author Professor Peter Snyder of the University of Pennsylvania, Philadelphia says that decisions about whether to offer treatment depends on knowing the risks, which “will necessitate larger and longer trials”.
Professor Eric Orwoll of Oregon Health and Science University, Portland points out that the benefits were modest and tended to wane over time. “At this point their clinical importance is uncertain. Therapy was not a panacea, and the findings alone might be insufficient to support a decision to initiate testosterone therapy in symptomatic older men.” The average age of men in the study was 72, 90% were white, most were obese and had high blood pressure and all had very low testosterone levels.
So who should take testosterone? Young men who aren’t producing testosterone because their testicles have failed certainly need to take it, in order to prevent bone and muscle loss. But men such as Sylvester, whose low levels reflect failure of the brain hormones that stimulate the testes into production, should not be given it, as it will impair fertility further.
Women such as Williams can try a low dose, but should not stay on it if it is not helping. And older men who are suffering from low libido, energy and erectile dysfunction and low testosterone due to age alone, need to wait to find out whether it is safe – the trials didn’t flag up any major toxic effects, but they weren’t powered to answer the safety question decisively.
Consumer advocate Dr Sidney Wolfe of Public Citizen says testosterone prescriptions in the US are 17 times higher per population than in the UK overall. And alarmingly, a fifth of those were for the non specific symptom of ‘fatigue’ and up to 9% were for men who had normal or high levels already. Some are given prescriptions without even having their levels checked. In 2014, Public Citizen actually filed a petition with the US Food and Drug Administration (FDA) requesting a strong health warning on all drugs containing testosterone.
Last year, the FDA denied that request but did issue a caution and required a labelling change to mention “a possible increased risk of heart attack and stroke with use.” Wolfe remains convinced that stronger action is needed to stem the rising tide of testosterone use.
