The Testosterone Revolution

World expert in the andropause, Dr Malcolm Carruthers, explains what to do if your get up and go has got up and gone.

What are the main symptoms of the andropause? On the sexual front the most common symptoms are loss of potency, loss of sex drive and loss of morning erections. The most common psychological symptoms are mild to moderate depression, irritability and an early reduction in memory and mental concentration. Physical symptoms related to the andropause are similar to those experienced by women, including joint aches and pains, dry and thinning skin, occasionally sweating at night and the feeling that the body’s thermostat has gone wrong, causing flushing. How do you find out if you are low in testosterone? On the whole, symptoms are a much better guide than blood tests.

Research [1] shows that if one relies purely on the blood testosterone level, over 80% of cases of the andropause would be missed. Further evidence [2] suggests that this is partly due to the phenomenon of ‘Testosterone Resistance’ where, as in insulin resistant diabetics, the body becomes resistant to the action of testosterone. It is more useful to measure the amount of ‘free’ or available testosterone. A doctor should measure both your testosterone level and the level of ‘Sex Hormone Binding Globulin’ (SHBG), which binds to, and hence inactivates testosterone. By knowing these two figures you can work out the ‘free’ testosterone. Salivary testosterone does also correlate with free testosterone but the use of this test is not yet fully accepted. However, this alone is not enough to make a diagnosis because there are many other risk factors that interfere with testosterone, for example drugs interfering with the testosterone receptors or stopping its production.

What are the risk factors? The age distribution peaks at 55, but often men suffer symptoms for three to five years, so the time of onset is similar to the female menopause, at age 50. If a man has had an infection, particularly adult mumps, and possible other viral infections such as glandular fever (especially during puberty when the testes are establishing their own immune identity), this can cause damage to fertility and testosterone production. A man may have enough testosterone to father children but not to carry him healthily into old age. Sexually transmitted diseases, such as non-specific urethritis, can damage the testes as can physical blows to the testes – including vasectomy.

Stress also has a major impact. Basically, anything that puts a man down will put testosterone down – loss of a partner, job, loss of sleep, lots of traveling and high stress jobs. Being overweight or having insulin resistance or diabetes all increase oestrogen dominance, which inhibits testosterone. Can women suffer from testosterone deficiency? I work primarily with men, however more and more attention is being paid to testosterone levels in women. A woman’s body produces four times more testosterone than oestrogen. In fact, women’s oestrogen is made from testosterone.

We know, for example, that declining oestrogen levels in the brain can lead to poor memory and that giving women testosterone can raise oestrogen levels in the brain. Hence, one can expect that a woman with low testosterone would experience all the symptoms associated with oestrogen deficiency including loss of sex drive and bone mass density. Progesterone, the other key female hormone, is a precursor for both oestrogen and testosterone. If a man is diagnosed with the andropause what’s the cure? If you are thought to have testosterone deficiency, then you should have at least a three month therapeutic trial of treatment with the hormone.

There are an increasing range of testosterone treatments, including pellets, injections, pills and more recently transdermal creams. Testosterone pellets, which last for six months, are a bit like putting a tiger in your tank, but are expensive and have been largely replaced by injections called Nebido (Bayer-Schering) which last 3 months. Many men prefer oral preparations, Restandol (Testocaps) by Organon, or transdermal gels such as Testogel (Bayer-Schering) or Tostran (Pro-Strakan). Of course, it is also important to make lifestyle changes that reduce risk. But my attitude is that if a man has lost his enthusiasm for life and love, you can often kick-start these by correcting testosterone deficiency and then they have more enthusiasm to reduce stress, alcohol and weight and change to an active holistic lifestyle which includes improving one’s diet. Are there any downsides to testosterone therapy?

Firstly, I recommend physiological levels of testosterone treatment and prefer methods of delivery that give a steady supply, equivalent to that which the body would naturally produce. Given the well proven increased risk of breast cancer with oestradiol and synthetic progestins one is right to look carefully at any possible increased risk for prostate cancer, which is very prevalent among men. To date there is no real evidence that testosterone therapy causes prostate cancer, in fact the suggestion that it does is now being considered a myth according to a review [3] of scientific articles.

We have followed over 1,700 relatively high risk men for up to fifteen years, fourteen of which developed prostate cancer. That is actually a lot lower than the current national average. Over-all by increasing prostate screening, and improving urinary function in older men, we are coming to regard testosterone treatment as actually being good for the prostate! Although I see no evidence that testosterone therapy could initiate prostate cancer it could conceivably aggravate it. For this reason I always measure a man’s Prostate Specific Antigen (PSA) which is a marker for prostate cancer. If it is raised then a diagnosis is made on the basis of ultrasound study and/or biopsy.

Screening for older men is a good idea anyway. By pre-sceening over 2,000 men I’ve identified early stage prostate cancer, which can then be treated, in 12 patients to date by doing this. There are now proper internationally accepted guidelines for safe testosterone therapy, and these are given in many publications such as those of the International Society for the Study of Men’s Health (ISSAM) [4]. However it must be emphasized that a simple questionnaire such as the Ageing Male Symptoms (AMS) [5], which has indentified many cases by on-line screening, is better for detecting testosterone deficiency than blood tests because of the resistance to the hormone which is present in most cases.

What about diet? A higher protein diet tends to put up testosterone, and put down sex hormone binding globulin, so you need enough protein. A strict vegetarian or vegan diet is more likely to be associated with lower testosterone levels. Also, very high fibre diets tend to raise SHBG, which binds to testosterone making it unavailable. High alcohol consumption is another risk factor. If a man has had a period of heavy drinking in their lifetime, their liver may forgive and forget but the testes, it seems, harbour grudges. Because of the decreasing availability of testosterone treatment within a constricting and hostile NHS, the initiative has been taken to make safe testosterone treatment available in a chain of Centre for Men’s Health Clinics based on the existing Harley Street flag-ship, the first being in Manchester opening in March this year.

These Centres will use the latest on-line internet technology to enable patients to fill in their own histories and complete diagnostic questionnaires and blood tests prior to seeing specialist consultants for examination and treatment. This will enable and encourage patients to play a greater role in their own diagnosis and treatment, and greatly increase the availability of this important form of treatment and preventive medicine. For more information: Read The Testosterone Revolution by Dr Malcolm Carruthers which is available for £10 inc p&p. Contact the Centre for Men’s Health, Suite 20 Harmont House, 20 Harley Street, London, W1G 9PH on 0207 636 8283 or email


1. M Carruthers & TR Trinick, ‘The validity of androgen assays’, Andrologia (2004), vol 36, pp 231-32.

2. M Carruthers, ‘The paradox dividing testosterone deficiency symptoms and androgen assays: a closer look at the cellular and molecular mechanisms of androgen action’, J Sex Med (2008), vol 5, pp 998-1012.

3. A Morgentaler, ‘Guilt by association: A historical perspective on huggins, testosterone therapy, and prostate cancer’, J Sex Med (2008), vol 5, pp 1834-40.

4. C Wang, E Nieschlag, R Swerdloff, HM Behre, WJ Hellstrom, LJ Gooren, JM Kaufman, JJ Legros, B Lunenfeld, A Morales, JE Morley, C Schulman, IM Thompson, W Weidner, FC Wu, ‘Investigation, treatment, and monitoring of late-onset hypogonadism in males: ISA, ISSAM, EAU, EAA, and ASA recommendations’, J Androl (2009), vol 30, pp 1-9.

5. TR Trinick, MR Feneley, H Welford, M Carruthers, ‘International survey shows high prevalence of symptomatic testosterone deficency in men’, Aging Male (2010), vol 14 (1).