Written by Olivia Hunt
7th Feb 2023 • 4 minute read
Reviewed by
Dr Nicole Harris MRCGP BSc (Hons)

Testosterone is a hormone produced by both men and women. Levels drop with age, but kidney or liver disease, alcoholism, and being overweight can also cause testosterone levels to drop. Men with low testosterone might feel tired, have a low sex drive, gain weight, feel depressed, and have low self-esteem. Women might also experience these symptoms even though they have lower levels than men. A healthy lifestyle can help boost testosterone levels, or your doctor might recommend testosterone replacement therapy (TRT).

What is testosterone?

Testosterone is a sex hormone (androgen). It’s sometimes called a “male” hormone. Women also produce testosterone, but in much lower amounts. Testosterone is essential for health and helps control many important processes in your body.

Testosterone in men

Even before birth, testosterone helps your reproductive organs (penis and testicles) to develop. During puberty, testosterone is also responsible for:

  • growth spurts
  • body hair
  • deepening of the voice

And throughout life, testosterone helps control:

  • bone density
  • muscle mass and strength
  • sperm production and fertility
  • red blood cell production
  • sex drive

Testosterone can also affect behaviour. For example, it’s linked to anger, aggression, dominance, competitiveness, and self-esteem.

Testosterone in women

Even though women don’t produce as much testosterone, it still plays a vital role. It helps control:

  • red blood cell production
  • sex drive
  • hormones that control menstrual periods
  • reproduction

High testosterone levels in women are one of the main symptoms of PCOS. You can check your levels at home using a PCOS test.  

What are the symptoms of low testosterone?

Low testosterone can cause lots of different symptoms.

Common symptoms of low testosterone in men include:

  • low sex drive (libido)
  • erectile dysfunction
  • weight gain — especially around the stomach
  • fertility issues
  • lack of body hair
  • excess breast tissue
  • low muscle mass
  • insulin resistance — increasing your risk of diabetes

Common symptoms of low testosterone in women include:

Low testosterone might also lead to mood and mental health issues in both men and women. For example, low levels are linked to depression, irritability, and concentration issues.

Learn how your testosterone levels affect your training with a sports performance blood test.

What are the causes of low testosterone?

In men, it’s normal for testosterone levels to drop with age. From the age of 30 to 40, testosterone levels drop just under 2% every year. But low levels can also be caused by:

  • being overweight or obese
  • alcoholism
  • kidney disease
  • liver disease
  • diabetes
  • pituitary or hypothalamic issues
  • damage to your testicles

In women, testosterone levels also drop with age. But low levels can also be caused by:

  • HIV infection
  • Turner's syndrome
  • Addison’s disease — your body doesn’t produce enough of certain hormones
  • early menopause and menopause
  • oophorectomy — surgery to remove one or both of your ovaries
  • adrenalectomy — surgery to remove one or both adrenal glands
  • pituitary disease — illnesses affecting the pituitary gland (found in your brain)
  • some medications — like oral contraception (the pill) and oestrogen therapy

How to test your testosterone levels

You can check your testosterone levels at home using a men’s health blood test or a PCOS blood test

We recommend doing these tests in the morning when your testosterone levels are at their highest. 

What are normal testosterone levels?

Normal testosterone levels in men are between:

  • 8.64-29 nmol/L

But sometimes, your GP might use an age-specific reference range. In this case, normal testosterone levels in men are between:

  • 8.64-29 nmol/L in < 50-year-olds
  • 6.68-25.7 nmol/L in > 50-year-olds

And normal testosterone levels in women are between:

  • 0.29-1.67 nmol/L

Total testosterone is a good initial indicator of your overall testosterone levels. A free testosterone test could also be useful if you have lower testosterone levels.

What is free testosterone?

You can also measure your free testosterone. This is the amount of testosterone available for your body to use — giving you a clearer picture of whether your levels are in the normal range.

Free testosterone is calculated based on your total testosterone, sex hormone-binding globulin (SHBG), and albumin level.

How to boost your testosterone levels

There are lots of natural methods you can try to boost your testosterone levels. These include: 

  • Cutting back on alcohol — aim for no more than 14 units a week (6 pints or 7 medium-sized glasses of wine).
  • Exercising — especially weight training and high-intensity interval training (HIIT).
  • Following a balanced diet — ensure you’re eating enough carbohydrates, protein, and healthy fats. Avoid yo-yo dieting and overeating.
  • Managing your stress levels — mindfulness, breathing exercises, and yoga are all great ways to reduce stress.
  • Getting enough vitamin D — try taking a vitamin D supplement between October to March.

Testosterone replacement therapy (TRT)

If the above lifestyle changes don’t work, a doctor might prescribe you TRT. 

TRT means getting synthetic testosterone through an injection, gel, or patch. This can help increase your muscle mass and sex drive. But there are some side effects, like skin reactions and weight gain, to be aware of. 

Sometimes your testicles can shrink, and sperm production can decrease. If you take it long-term, it might increase your risk of heart attack and stroke.

You shouldn’t start this therapy without supervision from a health professional. Self-medicating with synthetic testosterone (anabolic steroid) is dangerous and can cause aggressive or violent behaviour.