Why testosterone supplements might do more harm than good

The myth being peddled by testosterone sales companies is that men suffer from a similar hormonal change as women in later life.

They also play on the strong association in popular culture between testosterone and vitality.

In fact, where low testosterone does occur, it is almost always a marker of poor health, not the cause of it.

“Most men in the country who have a problem with testosterone are unfit. They may have problems with obesity, inactivity or diabetes,” said Dr Channa Jayasena, a consultant in reproductive endocrinology and andrology at Hammersmith and St Mary’s hospitals.

Treating men who do not need testosterone can expose them to serious medical risks, including a greater risk of blood clots and strokes.

It tricks the brain into thinking there’s enough testosterone, causing the testes to become temporarily dormant and shrink.

“We know from illegal sports drugs – people taking huge amounts of testosterone – you will get big muscles,” said Prof Grossman.

“But it comes at the cost of testicular shrinkage, infertility, acne, and we don’t know the long-term cardiovascular effects. Having very high levels of a hormone that shouldn’t be so high is undoubtedly not a good idea.

“No ethical doctor would give testosterone unless the level was abnormal”.

Dr Jayasena agreed, adding that the abuse of testosterone can become addictive.

“Giving testosterone when the body doesn’t need it switches off the testes temporarily and the higher the dose [you take], the longer it takes to wake them up again.

“That can cause fertility problems,” said Dr Jayasena. “It can cause dependency”.

The risk of blood clots and stroke is caused by excess testosterone stimulating the bone marrow to make more red blood cells, which can make the blood more “sticky”, he added.