Does TRT Build Muscle?

More and more men are realising that they have low testosterone and that TRT can be the answer to the symptoms they have learnt to live with for years. But does TRT have other benefits? Does TRT build muscle and help with performance in sports and the gym?

Here we look at the evidence to see whether TRT can do more than just cure your symptoms.

Testosterone and its muscle building effects

Testosterone is undoubtedly important for building muscle.

When men go through puberty and their testosterone levels rise, muscle mass increases along with widening of the shoulder girdle and an increase in bone density. All of these things contribute to making men the stronger sex, which is part of their protective role in the family.

One of the main actions of testosterone in the body is to increase anabolic activity which means bigger, stronger muscles, denser, tougher bones and faster healing with increased skin thickness.

Natural versus Unnatural Testosterone levels

An interesting study showed the difference between muscle gain on supraphysiological testosterone levels versus natural testosterone levels. The results were pretty impressive.

There were 4 groups of men and they were either training or not training with resistance exercise. They were also either taking testosterone or not taking testosterone.


TRT builds muscle study

What they found was extraordinary. Predictably, the men on testosterone who trained built more muscle than the men who weren’t on testosterone but also trained with resistance exercise. Similarly the men who didn’t train but were on testosterone also built more muscle than the men who didn’t train and also weren’t on testosterone.

However, what was really interesting was that the men who didn’t do any resistance exercise but were on testosterone built more muscle than the men who trained with weights but weren’t taking any testosterone.

This demonstrates the power of testosterone (and TRT) in building muscle. This is particularly true if you go from having low natural testosterone levels to high, top of range TRT levels of testosterone.

This is why TRT can build muscle in a lot of men and a lot of our patients see great results as well as all of the other benefits they notice.


Does TRT Build Muscle at achievable Testosterone levels?

When men are on TRT, it is not the same as taking a steroid cycle. Steroid cycles use very high testosterone doses which can cause serious damage to your health, particularly in the long term. 

Whilst these risks can be mitigated, the long term use of high doses of testosterone (and even worse other steroid compounds) can lead to problems with a person’s lipid profiles (cholesterol levels), prostates, and cardiovascular issues such as blood clots which can cause strokes and heart attacks.

There is no debate about the fact that steroid doses increase muscle growth. However, these doses clearly aren’t sustainable or recommended. But is it expected that TRT builds muscle on more sensible doses?

In essence, yes, TRT doses definitely help to build muscle, even in older men who don’t resistance train. In these men, injections increased lean muscle size by 5.7% and strength by 10-13%.

How to Build Muscle When on TRT

Building muscle on TRT should follow the same principles as growing muscle naturally.

Whilst you will grow muscle more quickly with higher testosterone levels (e.g. whilst on TRT compared to naturally with low levels of testosterone) there are similar techniques which work in both areas. The higher the testosterone levels, the less complex the techniques need to be.

1. Weight lifting – you should aim to increase weight or reps as much as possible to increase the resistance and strain on your muscles. Using a combination of reps and sets is beneficial. As you become more advanced at weightlifting the types of periodisation become more complex. You will also be able to add in more volume and recovery more quickly which then leads to greater improvements itself.

2. Protein intake – protein helps with protein synthesis and this drives muscle growth. Higher testosterone levels allow greater use of available protein and increased protein synthesis.

3. Use of supplements such as creatine – there are lots of supplements that are a waste of money. Creatine isn’t one of them, it is backed up by lots of evidence and shown to be very effective for muscle building and strength (which often go hand-in-hand).

4. Rest – getting enough sleep is an often-overlooked factor in muscle growth. This is crucial in allowing your body to repair muscle damage and grow back bigger and stronger.

5. Calories – getting enough calories is required for muscle growth, if you don’t have enough good calories then you will lose weight, not gain it. The more muscle you want to add, the more carbohydrates should be used alongside the aforementioned proteins. Fats also have a significant role to play.

6. Compound movements – don’t be afraid to squat, deadlift, bench and overhead press. These movements allow lots of weight to be added and use several muscle groups. They should be the main focus of your workouts with smaller isolation movements afterwards. You will never see a small man with huge biceps – you need to increase your frame and build as a whole before you can expect to grow big muscles on it! This is where compound exercises are really important. 


So does TRT build muscle?

In short the answer is: ‘Yes, if you need TRT for low testosterone levels and train effectively.’ This should be true of everyone on testosterone replacement therapy.

Whilst TRT is not a magic pill that will make you into the next Mr Olympia, it will probably put some muscle on your frame and help you to build even more muscle from the correct type of exercise.

Dr Chris Airey

Dr Chris Airey

Medical Director

This article has been medically reviewed for accuracy by Dr Airey on 12th September 2020.

Dr Chris Airey is a fully registered UK doctor with the GMC (General Medical Council) Reference No: 7490533.
He trained at the University Hospital Southampton and graduated as a Doctor with a joint Bachelor of Medicine and a Bachelor of Surgery, plus a Masters in Medical Science, completing his research project in the Medical Neurosciences Department.
He is undertaking a Master of Science course in Endocrinology and is a member of the European Society for Sexual Medicine, and the Androgen Society.
He has personal experience with taking Testosterone Replacement Therapy and is a pioneer in UK treatment protocols for Testosterone Deficiency Syndrome.