Testosterone: your five-minute guide
28 July 2023
Testosterone is widely recognised as the main male sex hormone. But did you know that women both produce and need it too?
Here's a quick guide to testosterone and how it affects your body.
What is testosterone?
Testosterone is the major sex hormone in males, in whom it plays a key role in the development of their reproductive systems.
One of the group of hormones known as androgens, it is derived from cholesterol and helps with:
- Penis and testes development
- The deepening of the voice
- Facial and pubic hair growth
- Muscle size and strength
- Bone growth and strength
- Libido
- Sperm production
But men are not the only ones who have testosterone. It's one of several androgens also found in females, in whom it helps with:
- Ovarian function
- Bone strength
- Libido
Fact or fiction?
A high level of testosterone makes you aggressive. Inconclusive! Some studies have suggested a link between testosterone and aggression, but according to Harvard Medical School researchers, testosterone's role in causing men to behave violently or aggressively is largely a myth. 1
Did you know?
Even though testosterone is a male hormone, women also produce it via their ovaries and adrenal glands.2 In fact, both men and women need the proper amount of testosterone to develop and function normally.
How is testosterone produced?
Men's brains control the production of testosterone by sending signals to the pituitary gland, which then instructs the testes to produce testosterone.
The brain also regulates the amount of testosterone in the blood and sends out further signals to reduce production should levels get too high.
In women, smaller amounts of testosterone are produced in the ovaries and adrenal glands.
Can you have too much testosterone?
Yes. Problems associated with abnormally high testosterone levels in men include:
- Low sperm count/impotence
- Higher risk of heart attacks
- Prostate enlargement (difficulty urinating)
- Liver disease
- Fluid retention (swelling of the legs and feet)
- High blood pressure/cholesterol
- Insomnia
- Headaches
- Increased muscle mass
- Higher risk of blood clots
- Stunted growth (in adolescents)
- Mood swings, irritability, and even delusions
Can women have too much testosterone?
Among women with abnormally high testosterone levels, usually due to polycystic ovary syndrome (PCOS), symptoms include:
- Irregular periods
- Reduced fertility
- Excess hair on the face and body
- Male-pattern baldness
- Weight gain
- Depression
- Anxiety
Fact or fiction?
Too much testosterone causes baldness. Fiction. Testosterone is involved in male balding, but high testosterone levels are not actually the problem. Balding occurs when the body converts testosterone into a chemical that causes the hair follicles on the head to shrink, making the hair become finer and finer until it disappears altogether.3
Can you have too little testosterone?
Yes. In males, testosterone levels peak during adolescence and early adulthood and start to decline - by about 1% a year - after the age of 30.
This decline is not great enough to cause problems for the average man; there's no sudden change that could be equated to the menopause among women.4
However, males of any age can experience hypogonadism, which is when an abnormally low level of testosterone is produced due to a problem in the testicles or the pituitary gland.
Symptoms of testosterone deficiency in adult men include:
- Reduced body and facial hair
- Loss of muscle mass
- Increased breast size
- Hot flashes
- Low libido, impotence, and infertility
- Irritability, poor concentration, and depression
- Brittle bones and increased risk of fractures
Among women, meanwhile, it is the last three symptoms on the list that are the most common.
However, there are times when having low testosterone levels is a good thing - even for men. It is thought, for example, that testosterone may stimulate the prostate gland and cause prostate cancer to grow. That's why treatment for prostate cancer often involves taking steps to lower testosterone levels.
How can I check my testosterone level?
The best way to check your testosterone level is via a blood test.
The NHS testing procedure involves a series of two blood tests, both taken in the morning.
To qualify for testing, you will have to demonstrate to your GP that you have symptoms indicating an abnormal level of testosterone.
If the level of total testosterone in both samples is found to be below a certain level, you should then be offered testosterone replacement therapy (TRT), which comes in various forms such as injections and gels.
What treatments are available for abnormal testosterone levels?
While TRT is the most common treatment for men with a testosterone deficiency, men with too much testosterone are more likely to be tested for tumours in the testes or adrenal glands.
Women with abnormally high testosterone levels, meanwhile, may be prescribed oral contraceptives or other hormonal treatments.
Both low and high testosterone levels can also be regulated by making certain lifestyle changes.
For those with overly high levels of testosterone, these include:
- Achieving and maintaining a healthy weight
- Incorporating certain foods into your diet, such as soy-based products, mint, and cinnamon
- Taking zinc, magnesium and/or vitamin D supplements
For those with too little testosterone, lifestyle changes that can help include:
- Doing more exercise, particularly weightlifting
- Reducing alcohol consumption
- Getting more sleep