TRTed: Should I take testosterone?

Take home points

• Testosterone is a hormone that promotes male characteristics. Testosterone levels are much higher in men than women.
• Testosterone levels in men normally start to slowly drop later in life. But if testosterone levels drop too low, this can lead to health problems.
• Testosterone replacement therapy (TRT) can be medically prescribed to treat symptoms of low testosterone levels. Men also take testosterone for recreational reasons, such as to build muscle.
• There are side effects and risks to taking any drug. Taking testosterone that is not prescribed carries even greater risks, including heart attacks, strokes, and liver or kidney failure.
• If you think you have symptoms of low testosterone, always consult your GP or medical professional.

What is testosterone?

Testosterone is a sex hormone and a type of steroid. It is produced in the testicles of men and in the ovaries of women and then travels around the body in the blood. Testosterone levels are much higher in males than females. The adrenal glands also produce a small amount of testosterone.

What does it do in the body?

Testosterone is a type of androgen, which means it promotes male characteristics.¹ Testosterone is important for men across all life stages, from early in the womb right up to late life. In the womb, testosterone stimulates the development of male reproductive organs such as testicles.¹ In puberty, testosterone stimulates growth in height, body hair, and sex drive. In adult life, testosterone stimulates sperm production and maintains the male characteristics that have developed so far.

Why do people take testosterone?

Whilst testosterone is produced naturally, some people take testosterone for medical or recreational reasons.

Medical use

Men may take testosterone for medical reasons when the levels of testosterone naturally produced in the body is too low (hypogonadism). This testosterone is called Testosterone replacement therapy (TRT). The testosterone used for medical purposes is a synthetic form of testosterone.¹ It can be taken as an injection or a gel that is applied to the skin.² This is prescribed by a doctor.

Recreational use

Men may also take testosterone for recreational purposes.³ This is often as a performance-enhancing drug, to improve physical appearance (e.g. build muscles) or athletic performance. These can be injected, applied as a gel or consumed as tablets.³

Men taking testosterone for performance enhancement often have completely normal levels of natural testosterone and show no symptoms of low testosterone. The exact numbers of men using testosterone or related anabolic steroids for bodybuilding is not exactly known, but is estimated at 0.1-0.2% of 16-59 year olds.⁴

Men may also take testosterone that is not prescribed if they think their natural testosterone levels are low but without speaking with a doctor.

What causes low testosterone?

Testosterone levels in men naturally start to decline by 1-2% each year from the age of 30 to 40.⁵ This slow decline typically does not cause any problems. However, if testosterone levels decline too fast and drop too low, it can lead to health problems. Low testosterone levels later in life is called late-onset hypogonadism. Late-onset hypogonadism is more common with increasing age, and estimated to occur in around 2-3% of middle and older aged men.⁶ Besides age, other factors can also lead to low levels of natural testosterone. This can include medications, chemotherapy and some genetic disorders.^{5, 7}

What are the symptoms of low testosterone?

Symptoms of low testosterone include:^{2, 5}

• Erectile dysfunction
• Low sex drive
• Depression
• Mood swings
• Muscle loss
• Increased belly fat
• Reduced ability to exercise
• General lack of energy and increased tiredness
• Sleepiness and difficulty sleeping
• Problems with concentrating and short-term memory

However, these symptoms can also be caused by factors other than low testosterone, such as stress, poor mental health, and lifestyle.² In the UK, around 9% of patients assessed by doctors for potential symptoms of hypogonadism test positive for low testosterone levels.⁸ Of which, 72% are over 45 years old.⁸

Should I take testosterone?

TRT should only be taken if it has been medically prescribed for clinical reasons to treat and reduce symptoms of naturally low testosterone levels.⁵ There should both be symptoms of low testosterone and blood tests to confirm low testosterone levels.⁵

The presence of any of the symptoms above does not immediately mean that low testosterone is the cause. This is because there are many other reasons for these symptoms. The first step should always be to speak with your GP.² If necessary, the GP will refer you to a medical professional specialising in hormones. They will measure testosterone levels in your blood and conduct other checks to rule out other possible causes. If you need to take testosterone, they will also perform checks to make sure you are safe to receive it.⁵

As with taking any medication, medically prescribed testosterone can come with side effects.⁵ Common side effects associated with typical TRT doses include:⁵

• Acne
• Oily skin
• Tender breasts
• Increased number of red blood cells

Before prescribing TRT, your doctor will ensure that any potential side effects or risks are made clear to you and minimised.

What are the risks of taking testosterone when it is not prescribed?

It is illegal to possess, import, or export anabolic steroids, including testosterone, in the UK. They are a Class C drug and can only be used when prescribed.³ Taking testosterone that has not been prescribed by a doctor (without medical advice) can cause serious side effects and addiction.³ When testosterone is not prescribed, no safety checks have been performed. There is also no ongoing medical observation to check for side effects.

As men taking testosterone for recreational purposes often have normal levels of natural testosterone naturally produced in the body, testosterone levels can be much higher than normal. This increases the chance of side effects and carries serious risks, including:³

• Heart attacks
• Strokes
• Liver or kidney failure
• Hypertension
• High cholesterol
• Prostate cancer
• Reduced sperm count and infertility
• Erectile dysfunction
• Hair loss
• Breast development
• Severe acne and chest pains

Testosterone misuse can also increase the number of red blood cells in blood, which makes blood thicker and more prone to clots. There are also mental side effects, including paranoia, mood swings, aggressive behaviour and hallucinations.³ This in turn can also lead to negative social impacts.⁴

There are also other risks. Men taking testosterone for recreational purposes often purchase it from unregulated sources on the internet. This can be very risky, as there is no guarantee as to what is being purchased and taken. It could be mixed with any other unknown substances, or the dose could be much higher than stated.

Speak to a healthcare professional

Testosterone should only be taken if you are prescribed it and clinically indicated by a medical professional.⁵ If you have any concerns regarding your health or whether you think you should consider taking testosterone, always consult your GP for advice and guidance. They will refer you for any necessary tests and ensure the correct diagnosis and treatment for any symptoms you may have.

References

1. Testosterone: What It Is, Function & Levels. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/24101-testosterone (accessed Dec 2, 2024).
2. The ‘male menopause’. nhs.uk. 2018; published online Oct 3. https://www.nhs.uk/conditions/male-menopause/ (accessed Dec 2, 2024).
3. Anabolic steroid misuse. nhs.uk. 2017; published online Oct 17. https://www.nhs.uk/conditions/anabolic-steroid-misuse/ (accessed Dec 2, 2024).
4. Mullen C, Whalley BJ, Schifano F, Baker JS. Anabolic androgenic steroid abuse in the United Kingdom: An update. Br J Pharmacol 2020; 177: 2180–98.
5. Bhasin S, Cunningham GR, Hayes FJ, et al. Testosterone Therapy in Men with Androgen Deficiency Syndromes: An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism 2010; 95: 2536–59.
6. Corona G, Rastrelli G, Maggi M. Diagnosis and treatment of late-onset hypogonadism: Systematic review and meta-analysis of TRT outcomes. Best Practice & Research Clinical Endocrinology & Metabolism 2013; 27: 557–79.
7. Nassar GN, Leslie SW. Physiology, Testosterone. In: StatPearls. Treasure Island (FL): StatPearls Publishing, 2024. http://www.ncbi.nlm.nih.gov/books/NBK526128/ (accessed Dec 2, 2024).
8. Gooren LJ, Behre HM. Diagnosing and treating testosterone deficiency in different parts of the world: changes between 2006 and 2010. The Aging Male 2012; 15: 22–7.