UNDERSTANDING TESTOSTERONE: ITS ROLE IN THE BODY AND EFFECTS OF EXOGENOUS TESTOSTERONE USE

By Dr Angela Servis BMBS MRCGP

Testosterone is a hormone that is primarily produced in the testes of males and is responsible for various physiological functions in the body. This hormone is well-known for its ability to improve athletic performance, but what else does it do?

The Role of Testosterone in the Body

Testosterone plays a crucial role in several bodily functions, including:

1. Muscle mass: Testosterone is essential for the development and maintenance of lean muscle mass.
2. Bone density: It helps in maintaining bone density and reduces the risk of osteoporosis.
3. Libido and erectile function: Testosterone influences sexual desire and erectile function in males.
4. Facial and pubic hair growth: It is responsible for the development of facial and pubic hair during puberty.
5. Cognitive ability, mood, memory, and quality of life: Testosterone also plays a role in cognitive function, mood regulation, and memory.

Testosterone Replacement Therapy (TRT)

In cases where an individual is diagnosed with testosterone deficiency, Testosterone Replacement Therapy (TRT) can help protect bone mass, restore cognitive function, and improve libido, erectile function, and quality of life.

Under the guidance of a qualified clinician, individuals can seek advice on prescribed medication and be monitored for any side effects. TRT can down-regulate natural testosterone production, and for that reason, it is a lifelong treatment that requires commitment.

Risks of Unregulated Testosterone Use

Taking testosterone from unregulated sources carries significant risks. Individuals taking testosterone from unregulated providers are not monitored by qualified clinicians for any physiological disruptions that would be identified through blood tests during treatment. 

Furthermore, the contents of the products are often unknown due to the lack of regulation. Exogenous testosterone use also down-regulates natural testosterone production, which can disrupt the delicate hypothalamic-pituitary-gonadal axis and potentially cause hypogonadism upon withdrawal of the exogenous testosterone.

Side Effects of Exogenous Testosterone Use

Exogenous testosterone use can cause several side effects, including:

1. Increased oestrogen levels: Elevated testosterone levels can lead to an increase in oestrogen levels, resulting in oestrogenic symptoms such as nipple tenderness or gynaecomastia (enlargement of breast tissue/Moobs). Raised oestrogen levels can also cause mood disruption and water retention.
2. Haematocrit levels: Elevated free (unbound) testosterone levels can cause an increase in haematocrit, which can increase the risk of thrombotic events (risk of clots).
3. Cardiovascular risks: Supra-physiological testosterone levels carry a risk of cardiovascular events.
4. Prostate cancer: While a poorly performed trial indicated that testosterone replacement therapy increased the risk of prostate cancer, subsequent studies have debunked this claim. However, patients with a history of prostate cancer should exercise caution as TRT could accelerate the cancer’s progression.

Considerations for Drug Testing

Some people will be drug tested for their occupation, so this is an additional consideration. If you need to go away at short notice for your work, or for any other reason, stopping testosterone suddenly can cause a rapid drop in testosterone and all the symptoms that accompany that, low mood, low energy, apathy and low libido.

Considerations for using finasteride for hair loss

Hair loss can be an additional side effect of TRT and supra-physiological exogenous testosterone use. Some of the mild to severe symptoms of associated psychological problems with hair loss are anxiety, anger, depression, embarrassment, decreased confidence, reduction in work and sexual performance, social withdrawal, and even suicidal tendencies.

There is a growing trend in taking Finasteride (AKA Proscar or Propecia) to reduce male pattern hair loss. It’s a drug that was originally developed to treat men with an enlarged prostate (benign prostatic hyperplasia, BPH). 

It’s an inhibitor of the 5α-reductase enzyme Type 2 and works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT). DHT has multiple roles in the body but acts as the primary androgen in the prostate, as well as in hair follicles, hence its use in hair loss.

Finasteride is widely available online, however, the potential side effects often aren’t discussed and they include persistent erectile dysfunction, depression, suicidal tendencies, loss of libido, anxiety, brain fog, memory issues and other neurological issues. Research has demonstrated reproducible side effects in animal models as well as in human studies.

The cause of post-finasteride syndrome is poorly understood and management of the condition is challenging and often unsuccessful but the effects listed above can be permanent. 

Unfortunately, no predictive factors for the risk of development of post-finasteride syndrome have been identified and it needs more research into the area as well as more information for those considering taking it. The true incidence of PFS as yet remains unknown. 

There are other medications that can treat hair loss that don’t carry the same risk of side effects. Tadalafil can be used to treat BPH and the lower urinary tract symptoms associated with the condition and it doesn’t carry the risks of these side effects. Tadalafil is in the same drug group as Viagra and is a PDE5 inhibitor.  It was originally designed to treat pulmonary hypertension but the trial participants reported significantly improved erectile function. Further studies found that this was due to the relaxation of the smooth muscle in the penile arteries. The smooth muscle relaxation in arteries has also been associated with a reduction in blood pressure. Interestingly it has also been shown to reduce serum oestradiol levels, which can be useful for people on testosterone replacement therapy.

Although the incidence of PFS is unknown, having treated men with the debilitating condition, I would advise that the risk-to-benefit ratio probably isn’t in favour of using this drug for the management of hair loss.

Conclusion

Testosterone replacement therapy can be beneficial as a treatment for testosterone deficiency. However, whilst having a great effect on strength and muscle mass, supra-physiological testosterone levels can pose significant long-term health risks that could disrupt natural testosterone production permanently.

Therefore, individuals should carefully consider the potential risks and benefits before using exogenous testosterone. Clinicians should guide and monitor patients to minimise adverse effects and ensure the treatment’s safety.

Dr Angela Servis BMBS MRCGP – www.edenclinicformen.com

After graduating from Peninsula Medical School, I started my Army career in Germany with an armoured engineer regiment and travelled to various countries supporting their activities finishing my time with them with a deployment to Afghanistan.

Following that I completed my GP training in Plymouth before getting posted to 29 Commando and after a brief stint with a signals Regt, I left the army after 17 years in 2022.

I developed an interest in Men’s Health after seeing changes in a soldier who was struggling with low mood and checking his testosterone levels on a whim and then realising I wasn’t sure how to manage his testosterone deficiency. This set me off on an educational journey, getting mentored by Professor Hackett from the British Society for sexual medicine and finally setting up my own CQC registered clinic in Plymouth City Centre. 

I now offer in-person and remote treatment for men who have testosterone deficiency or erectile dysfunction and for people who need support with weight loss.

Having witnessed the devastating impact that testosterone deficiency can have on men and how underserved it is within the NHS, I feel passionate about offering a wholistic approach to management through Eden Clinic. Offering lifestyle support, and exercise and nutrition advice for our patients in partnership with my husband Guy Servis who’s a strength and conditioning coach and health adviser.