Testosterone: a guide to the male hormone

Siski Green ( 17 June 2015 )

Why the male hormone is being touted as a treatment for everything from fatigue to a lacklustre sex life, for women as well as men



Testosterone boosts libido and energy levels, maintains muscle mass, keeps bones strong and even ensures your privates remain sensitive to touch. Levels naturally drop as we get older, but experts disagree as to whether this is a problem that needs treating.

After the age of 50 a man’s testosterone levels drop dramatically, to between 20 and 50 per cent of the peak level by the time he's 80 years old. But it’s not just about age: a man aged 50 in 2007 is likely to have lower testosterone levels than a man who turned 50 in 1997. Why? The scientists at the New England Research Institutes in the US who discovered this decrease aren’t sure. They’ve looked at rising obesity levels, a known testosterone-reducer, and even falling numbers of smokers, a habit that increases testosterone, but neither accounts for this change.

Testosterone in women 

“On average, a woman in her 40s has half the testosterone levels she had in her 20s,” says Dr Karlis Ullis, medical director of the Sports Medicine and Anti-Aging Medical Group in Santa Monica, California. “While this fall is natural, some women who suffer with the symptoms of low levels could find testosterone therapy useful.”

Why low testosterone makes you tired

It’s natural to feel a bit less energetic as you get older, but you shouldn’t confuse tiredness with the kind of extreme fatigue you’d feel if you had low testosterone levels. “A man who completely lacks testosterone has no 'get up and go' (I call this zest),” says human reproductive science Professor Richard Sharpe, of Queen’s Medical Research Institute in Edinburgh. “Give him testosterone and he wants to 'be up doing something', he has energy and drive. Lack of energy does not equate to low levels of testosterone, but it could do in some men.”

What causes low testosterone?

“Feeling low or despondent about life can be a symptom of many things, including a psychological or chemical imbalance, a side-effect of medication or even bad luck in life,” says psychosexual therapist Vicki Ford, author of Overcoming Sexual Problems (Constable & Robinson, £9.99). “But if you’ve gone down those avenues of thought, and nothing has helped, it could be worth getting your testosterone checked.”

Heavy drinking messes your hormones about, resulting in lowered testosterone levels. Imbibe more than the 'safe' limit of 20 units a week (for men), 14 units for women, and your testosterone will drop by 20 per cent; and if you suffer from liver damage because of excessive drinking, levels can drop to 50 per cent.

Watch your waist

Fat cells – particularly those around your midriff – convert testosterone into estradiol, a form of the female sex hormone oestrogen. “As testosterone declines with age men see an increase in abdominal fat,” says Professor Sharpe. “This change tends to further reduce T levels and a sort of vicious circle is set up.” So the bigger the tyre around your waist, the more you convert, leaving less of the muscle-boosting, desire-enhancing hormone testosterone in your body.

“Avoidance of getting fat as you age is therefore one of the truly positive things you can do as you get older to ensure you ‘get the most out of your testosterone’,” advises Professor Sharpe.

“Women with low testosterone levels – similar to those experienced by women during menopause – can find it extremely difficult to lose excess weight,” adds Dr Ullis. “And taking oestrogen and progesterone supplements can exacerbate this effect.”

Increase your sex drive

“Low libido in both men and women is more often a symptom of psychological issues,” says Ford. But if you are suffering from one or more of the symptoms above, it is possible low testosterone might be the cause. “Several studies have shown that injections of testosterone improve sexual desire in post-menopausal women – and a middle-aged woman’s sex drive is also determined by the level of testosterone in her body,” says Ford. “For men, below-average T-levels will dramatically reduce the ability to get and maintain an erection.”

Physical and psychological causes

Before you rush off to book an appointment with your GP, take heed: “Very few men have categorically abnormal – low testosterone levels, but the normal range for adult men is huge and it’s likely, but hotly debated, that there is a larger number of older men in whom testosterone levels may be suboptimal, affecting their wellbeing,” says human reproductive science Professor Sharpe. There are many potential physical and psychological causes of ‘disorders’ that might also stem from having low testosterone – and not all men with these symptoms will benefit from testosterone injections or patches – the issues are just as hotly debated when it comes to women and low testosterone. “For these reasons, there’s an understandable reluctance to offer this type of treatment to patients,” adds Sharpe.

The money involved in treating low testosterone levels

“This whole subject is very contentious -- mainly because there's a lot of money in convincing people they have a low testosterone, and then selling it to them” says Dr David Delvin, GP and family planning adviser. “In the Harley Street area, there are thriving private practices and clinics which make a fat living out of doing just that. In 40 years of medical practice -- much of it involving sexual medicine -- I have seen less than a dozen men who genuinely had a low testosterone, and I can't recall seeing any women who had a low testosterone level (except after gland surgery). I suspect the average GP would fall about laughing if you asked whether fatigue was likely to be due to testosterone deficiency.

“There is no way in which people can decide if they have a low testosterone level, except by getting a blood test. It's rare for GPs to be asked for such a test, and many GPs might well be unwilling to order it on the NHS. An alternative would be to get it done privately; private labs in London tend to charge about £60 for this test.”

Boost testosterone levels

If a blood test does reveal that your testosterone levels are too low, you could be prescribed a gel, which is applied to the skin; a patch, which you can wear on your outer thigh, for example; or an injection.

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