Testosterone replacement therapy, what is it?
Testosterone replacement therapy is the administration of the testosterone hormone into the body, to replace low levels of natural production.
It is called replacement because the natural production of the body reduces with the addition of exogenous testosterone (from outside the body) and is eventually replaced (this can be avoided by the use of HCG).
You can learn more about testosterone replacement therapy on our TRT page.
Testosterone levels decline by around 1% per year after the age of 30.
As well as this SHBG increases in the body with age, leading to lower free testosterone levels.
In some men this leads to low testosterone symptoms.
Other young men have conditions such as damage to the testicles from cancer or varicoceles, pituitary issues, genetic problems that lead to incomplete sexual development or have low testosterone for unknown reasons.
What are the Main Benefits of TRT (Testosterone Replacement Therapy)?
If you have only just heard about testosterone replacement therapy then you’d be forgiven for being a bit skeptical about the benefits of TRT.
At first glance the benefits look too good to be true, improved physique, better mood, better sex, more confident and better health…
Are these benefits real or are they overblown? How likely are you to really notice everything on this list and how long does it take for the benefits to be seen?
What are the benefits of TRT?
Improved mood and cognition
Jung and Shin (2016) demonstrated that the benefits of testosterone replacement therapy improved various aspects of mental health in men with testosterone deficiency.
They noted improvements in memory, mental acuity and mood.
In this study there were very few side effects, and none were serious. It is common for men who start treatment to notice a return to normal levels of brain function, where before they suffered from ‘brain fog’. Brain fog is when men struggle to perform simple mental arithmetic, remember things that happened recently, and find concentrating difficult.
They noted that men may also find that their motivation and drive is reduced:
‘The effect of testosterone administration on cognitive function and depression in hypogonadal men is believed to be related to the enhancement of brain perfusion, which is supported by the fact that there are androgen receptors in the brain, suggesting that steroid hormones play a role in neuronal function.’
Interestingly they go on to hypothesize the potential benefits this could have on men with other mental health conditions. In particular, they refer to a study on men with mild Alzheimer’s.
‘The effects of TRT in men with mild cognitive impairment or Alzheimer’s disease have been evaluated in small placebo-controlled trials. For example, Cherrier et al (2005) evaluated a sample of 32 subjects, which included 17 men with mild cognitive impairment and 15 with Alzheimer’s disease. At the 6-week follow-up, patients who received TRT showed significantly better scores regarding spatial memory, constructional abilities, and verbal memory compared to those noted in the placebo group. Taken together, these results suggest that TRT has a beneficial effect on cognitive function.’
This is clearly a very interesting finding and something that needs further research. There is some evidence that low testosterone reduces perfusion (supply of blood to tissues) in various areas of the body. Improving testosterone levels often provides relief from conditions such as diabetes that have the side effect of reducing blood supply to regions.
Improved libido (sex drive)
Hackett et al. (2017) found that men with type 2 diabetes and low testosterone saw large improvements in sexual desire and erection quality after starting testosterone replacement therapy. This is a common benefit we see in our patients within the first 6 months of TRT.
Khera et al. (2011) showed that TRT with a testosterone gel significantly improved sexual function including libido in a large study of 840 men.
This is a common benefit we see in our patients with improvements seen by the first 6 months of TRT.
Improved erectile function
There are many medical treatments for erectile dysfunction. Most very effective for men who have mechanical issues preventing an erection.
However, in some men, the issue isn’t as much an inability to get an erection, which can be a mechanical or biochemical issue but more of a combination of a lack of desire and willingness to engage in sexual activity. This can often be a cause of erectile dysfunction which stems from low testosterone.
In men with low testosterone, improving these levels to normal often results in a return to normal erectile function.
Does TRT improve bone density?
A common effect of low testosterone is reduced bone density. This is partly due to low testosterone and partly due to the reduction in estrogen that results (as estrogen is converted from testosterone in men).
Increasing testosterone levels improves bone density, particularly in the spine where older men often suffer from compression fractures.
The main effect on bone density is most likely driven by estradiol levels, however this is mainly a by-product of testosterone in men as it is converted by the aromatase enzyme.
As a result, men with low testosterone will have lower bone density, and increasing testosterone will improve estrogen levels.
Does TRT improve your lifespan and prevent aging?
Regardless of the potential side effects listed previously, if taken properly, TRT can improve your health and lifespan.
In a recent, large study, TRT was shown to reduce the number of men who died from all causes compared to controls who weren’t taking TRT and had low testosterone. Evidence shows that testosterone is cardioprotective and good for heart health.
Goodale et al even state that ‘ there currently is no credible evidence that T therapy increases CV risk and substantial evidence that it does not.’
They go on to talk about the various benefits of that TRT has been demonstrated to have on the heart and general health:
‘Testosterone replacement therapy (TRT) has been shown to improve myocardial ischemia in men with CAD, improve exercise capacity in patients with CHF, and improve serum glucose levels, HbA1c, and insulin resistance in men with diabetes and prediabetes.’
Testosterone is also converted into estrogen in men. If men have low testosterone they often also have low estrogen. Estrogen is really important in men, it is protects the cardiovascular system, joints and other connective tissue, whilst helping with healing.
It is also well established that men with low testosterone are at greater risk from cardiovascular issues than those with normal testosterone levels.
Increased muscle mass, strength and reduced body fat
There are lots of studies which demonstrate the impressive effects of testosterone on men’s muscle mass, strength and body fat levels.
It is something that most men who start testosterone notice – a dramatic change in their physique.
Testosterone is an effective muscle mass builder by increasing the protein synthesis required for growth. It also improves neuromuscular function which results in strength increases. This is part of the androgenic effect of testosterone and includes the effects of DHT (dihydrotestosterone).
Men with higher testosterone levels tend to have lower overall visceral and abdominal body fat levels. Both of these things (when raised) are bad for overall health and lead to increased mortality rates.
However, TRT is not a magic bullet, whilst is does increase muscle very effectively, it will not shed body fat effectively on its own. A consistent workout regime and a healthy diet are paramount to improving this – testosterone does make the dieting process much easier for those who struggle to lose bodyfat.
How long does it take for TRT to start working?
In most patients, the benefits of TRT take from 3 to 6 months to be fully realized. Some benefits, such as bone density, fat loss and muscle mass increases, will continue to improve for longer than 6 months.