2024 Guide

TRT - Essential Guide to Testosterone Replacement Therapy [2024]

Uncover the benefits, understand the side effects, and learn how TRT can transform health, mood, and energy levels with this deep dive on TRT. Essential reading for anyone considering or managing TRT patients.

Whether you’re battling the symptoms of low testosterone or just exploring its transformative potential, this guide is curated with insights from comprehensive peer-reviewed research and real-world clinical experience after managing over 1,500 TRT patients in Australia.

What is TRT?

Testosterone Replacement Therapy (TRT) is a medical treatment aimed at restoring testosterone levels in individuals diagnosed with low testosterone, also known as hypogonadism. TRT is designed to bring testosterone levels back into the normal range to alleviate symptoms associated with its deficiency and improve overall quality of life - as well as reducing the adverse health outcomes from having low testosterone.

TRT vs. Other Hormone Replacement Therapies

Unlike other hormone replacement therapies that might target a spectrum of hormones such as progesterone, or thyroid hormones, TRT specifically focuses on testosterone. Each hormone therapy has its unique role and target conditions, but TRT is dedicated to addressing issues arising from testosterone deficiency.

TRT can often include the management of estrogen levels in men, due to the aromatisation (conversion) of testosterone to estrogen - which can be significantly high in some patients, generally in relation to poor overall health and elevated body fat levels.

How is TRT used in the clinical setting?

TRT has a clear medical application: to treat low testosterone (hypogonadism). Hypogonadism can be either primary (originating from an issue the testes resulting in poor function and production of testosterone - often trauma or previous infections) or secondary (where the testicular function may be adequate, but the signal to produce testosterone is weak, due to either dysregulation in the hypothalamus or pituitary gland - or other issues causing the pituitary to down regulate gonadotropins FSH and LH, which signal to the testis to produce testosterone).

TRT can be an effective treatment in both cases. It is distinct from other hormone therapies and the use of anabolic steroids, with a specific focus on restoring health and resolving symptoms that arise with low testosterone, rather than enhancing physical performance or muscle size.

What is the difference between TRT and anabolic steroids?

It's important to differentiate TRT from the use of anabolic steroids. Anabolic steroid use for bodybuilding or sport performance enhancement purposes generally includes the use of testosterone in very high doses and is often paired with other androgenic compounds used to increase muscle mass and physical performance.

How is high dose testosterone used in a non-medical setting?

  • Increase muscle mass and strength
  • Improve recovery
  • Improve fitness and athletic performance
  • Losing weight

These substances and high doses can lead to significant health risks and side effects - often these compounds are not well researched, especially at the doses at which they are utilised. Testosterone at supra physiological doses can also result in adverse health outcomes.

In contrast, TRT is a clinically supervised therapy that aims to normalise testosterone levels, adhering to medical guidelines to ensure safety and effectiveness. The goal of TRT is purely therapeutic, focusing on mitigating the negative health impacts of low testosterone, and alleviating symptoms such as fatigue, low mood, low sex drive, decreased muscle mass, and reduced bone density.

What are the benefits of TRT?

Testosterone plays a crucial role in so many part of a man’s life. For patients that restore their testosterone and resolve their hypogonadal state often report significant improvements in overall wellbeing, and resolution of most of their initial symptoms.

Improved Mood and Well-being

Testosterone has a significant impact on mood and overall sense of well-being. TRT can reduce feelings of depression, irritability, and fatigue, leading to an improved quality of life - if those symptoms are coming from low testosterone. TRT will likely not help depression if it is coming from something else, or living a depressing life.

Improved Motivation and Drive

Testosterone plays a key role in dopamine production, and can significantly lower motivation and drive when in a hypogonadal state. Many men no longer have the motivation to exercise, enjoy the company of friends and family, and often fall into bad habits. TRT can often increase and restore their motivation and drive, getting them back on track with healthier lifestyle habits.

Enhanced Cognitive Function

There's evidence suggesting that testosterone influences cognitive abilities, including memory and concentration. TRT may help improve focus, memory retention, and other cognitive functions. Testosterone plays an important role in dopamine production and regulation. A common symptom of low testosterone is ‘brain fog’, and TRT can often help reduce these symptoms.

Increased Libido

Testosterone is directly linked to libido or sex drive. TRT can significantly improve sexual desire and erectile function in men experiencing low testosterone-induced sexual dysfunction. If low sex drive is coming from chronic stress or another disease state, TRT will likely not improve sex drive.

Improved Muscle Mass and Strength

TRT can significantly increase muscle strength and mass by promoting protein synthesis, an essential factor in muscle growth. This is particularly beneficial for men experiencing muscle weakness or loss of muscle due to low testosterone levels.

Enhanced Bone Density

Testosterone plays a crucial role in bone mineralization and helps in maintaining bone density. TRT can help prevent osteoporosis, a condition where bones become fragile and more prone to fractures.

Increased Energy Levels

Low testosterone often leads to fatigue and a decrease in energy levels. TRT can help restore energy, making daily activities more manageable and enjoyable. Many patients report being fatigued from the moment they wake up, to the moment they get home. Work performance can suffer, and so can family life due to having no energy.

Improved Quality of Life

The combined physical, mental, and emotional benefits of TRT contribute to a significantly improved overall quality of life. Men undergoing TRT often report a renewed sense of vitality, better performance in their personal and professional lives, and a more positive outlook on life.

Many men who treat and resolve their low testosterone often notice a significant improvement in almost every area of their life (given there are no other health complications or poor health issues).

Work performance is better - due to improved cognitive function. They are often more driven in the work environment and may want to further develop their careers, or move into a new industry that they are more passionate about. Relationships can flourish again due to improved sexual intimacy and no more resentment due to ED or low sex drive. Family time improves due to having more energy and vitality.

It’s worth noting that not every TRT patient experiences ‘life changing’ results. Generally speaking, the worse a patients initial symptoms were, and the longer they were hypogonadal, the more pronounced the benefits of TRT can be.

TRT is also not a silver bullet. Men on TRT still have to actively improve their mental and physical health. It won’t resolve your childhood trauma, it won’t change the poor habits you’ve accumulated over the last 5 years, it won’t fix a lifelong period of being in a metabolically diseased state, and it won’t put in the work for you.

How long does TRT take to work?

The most commonly prescribed TRT protocol is Testosterone Enanthate, which is a self administered intramuscular injection twice per week. This protocol often takes up to 6 weeks to reach a steady state due to it’s long half life, and patients generally report slight symptom improvement from the 2nd week to the 8th week.

Most patients only realise the full potential of symptom alleviation after 6-12 months of being on a dose that is optimised for them - based on serum blood tests looking at their testosterone levels.

Some patients who have been in a hypogonadal state for very long periods of time, it can take longer to resolve their symptoms - sometimes it can take up to 2 years to notice significant improvement. Unfortunately being in a chronic hypogonadal state can change the behaviour of a male, especially if they have been hypogonadal during their maturing age (17-25 years).

This can result in learned behaviour such as anxiety, social anxiety, lack of confidence, poor focus, lack of sexual encounters due to the above and depression. Having low testosterone can wreak havoc on the development of a male no matter their age.

What causes low testosterone?

Low testosterone, also known as hypogonadism, can have various underlying causes. It generally stems from either primary or secondary hypogonadism, each with distinct origins and implications.

Primary Hypogonadism

Primary hypogonadism, also known as testicular failure, occurs when the testes themselves fail to produce adequate testosterone. This failure can result from a variety of factors, including:

Genetic Disorders

Conditions like Klinefelter syndrome or Turner syndrome can cause congenital testicular dysfunction.


Certain infections, such as mumps orchitis, can damage the testes, leading to reduced testosterone production.

Injury or Trauma

Physical injury to the testes, often from accidents or surgery, can impair their function.

Cancer Treatment

Radiation therapy and chemotherapy can adversely affect the testes, reducing testosterone production.


Excess iron in the body can damage the testes, reducing testosterone production.

Autoimmune Disorders

Some autoimmune conditions can target and damage the testes. Although rare, these can include: Autoimmune Orchitis, Autoimmune Polyglandular Syndrome and Lupus.

In primary hypogonadism, the problem lies in the testes themselves, leading to low testosterone levels despite normal signalling from the brain's hypothalamus and pituitary gland.

Secondary Hypogonadism

Secondary hypogonadism, is the more common form of hypogonadism and arises from problems with the signalling of hormones such as FSH (follicle stimulating hormone) and LH (luteinizing hormone) which regulate testosterone production. Both of which are regulated in the hypothalamus and pituitary gland. This condition involves inadequate stimulation of the testes to produce testosterone

Secondary hypogonadism differs from primary hypogonadism because the testes themselves might function properly, but they are not receiving adequate stimulation from the brain to produce testosterone


Obesity can cause androgen suppression due to increased aromatase activity in adipose (fat) tissue, leading to higher conversion rates of testosterone to estrogen. This hormonal imbalance reduces testosterone levels, contributing to primary hypogonadism. Additionally, obesity can lead to chronic inflammation and insulin resistance, both of which further impact hormonal health.


Excessive alcohol consumption can damage the liver, reducing its capacity to metabolize hormones and leading to higher estrogen levels, which suppress testosterone. Alcohol consumption can also cause excess aromatisation, resulting in elevated estrogen levels, which can then down regulate testosterone production.


Poor nutrition, especially diets low in essential nutrients and high in processed foods, can negatively affect hormone production and overall health.


Recreational drug use can interfere with the endocrine system, disrupting hormonal balance and leading to reduced testosterone production.


As men age, there's a natural decline in testosterone production due to reduced testicular function and slower response from the pituitary gland. This age-related decrease can lead to primary hypogonadism.

EDCs (Endocrine Disrupting Chemicals)

Endocrine disrupting chemicals (EDCs) are substances that interfere with hormone production and signaling. These chemicals, found in plastics, pesticides, and some personal care products, can mimic or block hormones like testosterone, leading to primary hypogonadism. There is growing evidence showing how prevalent and common EDCs are.

Previous Androgen Use

The use of androgens like anabolic steroids or selective androgen receptor modulators (SARMs) can suppress the body's natural testosterone production. When individuals stop using these substances, the HPTA (hypothalamic-pituitary-testicular axis) or testes might not fully recover, leading to permanent reductions in testosterone levels.


These can suppress the hypothalamic-pituitary-gonadal axis, reducing testosterone production.

SSRIs (Selective Serotonin Reuptake Inhibitors)

These antidepressants can affect libido and reduce testosterone levels. Many men we speak with are misdiagnosed with depression by their GPs and are prescribed SSRI’s, which can further lower their testosterone levels.


Some can lead to elevated prolactin, suppressing testosterone production.

Medical Cannabis

Heavy and chronic THC use can lead to hormone imbalances and reduced testosterone.

Liver Damage

A damaged liver affects hormone metabolism and detoxification, leading to hormonal imbalances.


Both Type 1 and Type 2 diabetes can impact hormone production and lead to reduced testosterone.


The disease and its treatments can affect hormone levels and disrupt testicular function.

Brain Injury

Trauma to the brain can impair the hypothalamic-pituitary axis, affecting testosterone signaling.


Lack of essential nutrients can inhibit testicular function and hormone production.

Pituitary Tumor

Tumors in the pituitary gland can disrupt hormone signaling, leading to decreased testosterone production.

Side effects of TRT

While Testosterone Replacement Therapy (TRT) offers numerous benefits for men diagnosed with low testosterone, it's essential to be aware of the potential risks and side effects associated with the treatment. Side effects are often dose dependant, meaning the higher the dose of testosterone is more likely to cause side effects.

Here are some of the key considerations:

Increased Hematocrit on TRT

TRT can lead to an increase in red blood cell production, which can result in an elevated hematocrit level. High hematocrit levels can thicken the blood, potentially increasing the risk of thrombosis (blood clots). This condition requires regular monitoring and, if necessary, treatment adjustments to mitigate risks. The increase in Hematocrit can generally be seen linearly in a dose dependant manner. Once off high readings can often result from dehydration at the time of the blood test.

It is quite often for men who notice a significant increase in Hematocrit to have another medical condition contributing to this. Sleep apnea often increases blood pressure, and can also increase Hematocrit levels. For many men who have ‘mild’ or ‘moderate’ sleep apnea, starting TRT can exacerbate this and make it worse, causing a further increase in Hematocrit levels in combination with the increase due to TRT.

In the clinical setting elevated hematocrit is quite rare, and can be resolved by:

  • Lowering the dosage
  • Investigating additional medical condition such as sleep apnea
  • Venesection (therapeutic blood drawing) every 3-4 months

TRT can worsen sleep apnea

For individuals with pre-existing obstructive sleep apnea, TRT might exacerbate the condition. Sleep apnea can lead to significant health issues, including cardiovascular problems, if it worsens. Patients with known sleep apnea should be closely monitored during TRT. TRT can also cause sleep apnea in some patients if they are holding excessive amounts of body fat, or have developed more neck muscles.

What impacts does TRT have on fertility?

TRT can suppress male sperm production by reducing the secretion of gonadotropin hormones such as FSH and LH, which are critical for sperm production. Men considering future fertility should discuss potential impacts with their healthcare provider before starting TRT.

Many men who start TRT may wish to build a family of their own in the future. When fertility is desired within 6 months of commencing TRT, HCG (Human Chorionic Gonadotropin) can be prescribed to stimulate leydig cells, and keep sperm production active. If a TRT patient is planning on having a baby in the future (12+ months) HCG does not have to be taken alongside TRT from initiation, it can be commenced during treatment as a fertility medication and would be administered alongside TRT. HCG has been indicated in many studies as an effective fertility medication for men.

Some clinics and doctors advise patients who desire long term fertility to take HCG from day 1 of starting TRT. Although this may be effective, there are no long term studies showing the efficacy of this approach, or the safety profile of taking HCG chronically for years on end. Given the above, HCG administration should be limited to short periods when fertility is desired, and once pregnancy is confirmed, it’s use should be ceased.

Can TRT impact cholesterol?

Although evidence is mixed, some studies suggest that TRT can affect cholesterol levels, potentially altering the balance between LDL (bad cholesterol) and HDL (good cholesterol). Monitoring lipid profiles is an important part of managing cardiovascular risk in patients undergoing TRT.

Many men who start TRT begin exercising more frequently and eating healthier, as a result we often see improvement in lipid profiles. However if no increase in exercise or healthier nutrition models are followed, then lipid profiles can remain the same, or worsen.

Can TRT impact prostate health?

The impact of TRT on prostate health is complex and requires careful consideration. While current evidence does not conclusively link TRT to an increased risk of prostate cancer, it may exacerbate symptoms of benign prostatic hyperplasia (BPH) such as urinary difficulties. Some studies indicate that having low testosterone is a risk factor for prostate cancer, and can make it far more aggressive.

Need for ongoing monitoring

Regular follow-up appointments are crucial to assess the effectiveness of the therapy, adjust dosages if needed, and monitor for side effects. Blood tests and discussions about any new symptoms are important components of ongoing care.

Something else to be aware of, is that TRT can take some trial and error to get the dosage dialled in and get you feeling better. Many men on TRT need their Total and Free Testosterone levels to be towards the top of the physiological range to notice complete symptom alleviation.

TRT is also a long term medication. Most guys that start TRT stay on for their entire life. This is another point that needs consideration as long term compliance is required to ensure TRT treatment to be effective.

How is TRT taken?

Testosterone Replacement Therapy (TRT) can be administered through various methods, each with their own set of advantages and disadvantages. The choice of administration should be personalised, taking into account the patient's lifestyle, preference, and medical history. However, it's widely recognised that certain protocols, particularly twice-weekly self-administered intramuscular injections with Testosterone Enanthate or Cypionate, offer a more effective and controlled approach to TRT. This is a common finding that most competent TRT providers (clinics and doctors) across the world have noted.

Below is a comparison of the different administration methods, highlighting the efficacy of the twice-weekly injection protocol.

1. Frequent injections (Testosterone Enanthate or Cypionate)

Consistent Serum Testosterone Levels

2-3 x per week self administer injections help maintain more stable testosterone levels, reducing peaks and troughs associated with less frequent dosing. As a result patients generally report feeling more stable and noticing consistent symptom alleviation throughout the week.


Generally less expensive than gels, patches, or pellets.

Easier optimisation

Allows for precise dosage adjustments based on blood test results and symptom management. Pathology is generally done at the ‘trough’ (when due for administration) and this level is optimised to ensure levels are not entering the hypogonadal range at any stage during the week.


Requires comfort with self-injection, which might be daunting for some individuals to begin with. Clinics and doctors generally provide patients with adequate material to educate and train themselves on how to safely self administer their TRT.

Injection Site Reactions

Although quite rare, there is potential for pain, redness, or swelling at the injection site. Which can be a result of poor technique or the medication itself.

Despite these cons, twice-weekly injections of Testosterone Enanthate or Cypionate are considered one of the most effective TRT protocols due to their ability to maintain stable testosterone levels, minimising side effects and optimising treatment outcomes. These protocols are considered the ‘gold standard’ by most leading TRT doctors and clinics all over the world.

2. Infrequent injections (Testosterone Enanthate, Cypionate or longer esters)

Less injections

Injections can be done every 2-3 weeks for Enanthate or Cypionate, or every 10-12 weeks for Undecanoate - normally by a doctor or nurse at a clinic. This is a somewhat outdated protocol, but still prescribed to countless amounts of patients.

Fluctuating levels

Due to half life of Testosterone Enanthate being 4-7 days, this results in very large peaks and troughs, which many men do not respond well to, and causes more side effects. Same can be said about undecanoate due to the injections being too spaced out (generally every 10-12 weeks in Australia).

The above graph are serum testosterone levels after a single injection of testosterone enanthate dosed at 200mg. We can see testosterone enters supraphysiological range, and then lowers into the hypogonadal range. Testosterone enanthate is commonly administered at an interval of every 2-3 weeks, which leads to large peaks and troughs.

The above graph was generated using a tool that looks at the half life and drug clearance of medications and uses literature to predict serum testosterone levels. The comparison is using 250mg every 14 days, and 62.5mg every 3.5 days. The dose over the month is the exact same, but we can see how significant the difference is in terms of stability and fluctuation of levels.

These protocols are generally prescribed by GPs or Endocrinologists who are not up to date and are extremely outdated. The CMI and package insert of Testosterone Enanthate (Primoteston) calls for a large single injection every 2-3 weeks, however given the half life of the medication is 4-7 days this results in sub optimal symptom alleviation.

3. Gels or creams

Ease of Use

Simple daily application on the skin.


No needles or injections required.

Risk of Transfer

Possibility of transferring testosterone to others through skin contact.

Inconsistent Absorption

Factors like skin barrier and application area can affect absorption rates. Generally less than 10% of the medication is absorbed, and other factors like sweating after application and lower absorption further.

Difficult to optimise

Short half life of 12-24 hours makes it difficult to optimise trough levels.

Lack of benefits

Anecdotally many patients, providers and clinics see a far lower efficacy rate in comparison to injectable testosterone.

4. Pellets

Low Maintenance

No need for daily or weekly administration after placement.

Surgical Procedure

Requires a minor procedure for pellet insertion.

Inflexible Dosing

Adjusting the dose requires pellet removal or addition

Non stable

Pellets do not provide serum levels as stable as twice weekly injections

What are the common pitfalls of TRT protocols?

The effectiveness of Testosterone Replacement Therapy (TRT) can be significantly influenced by several key factors, including dosing, frequency of administration, and the individualisation of treatment plans. A one-size-fits-all approach to TRT often fails to achieve optimal outcomes and can lead to a range of issues, underscoring the necessity for a tailored treatment strategy.

Many providers initiate patients at a low dosage, and then get blood work done after a few months to assess the individual response, and either titrate the dose up, or down in accordance with serum levels and symptom alleviation.

TRT Dosing: The Balancing Act

The dose of testosterone prescribed in TRT plays a pivotal role in managing symptoms of low testosterone and achieving the desired therapeutic outcomes. However, the same dose of testosterone can have varying effects on different individuals. For one person, a particular dose may elevate testosterone levels above the desired range, potentially leading to side effects such as increased hematocrit, sleep apnea, or mood swings. For another, the same dose might not adequately raise testosterone levels, leaving symptoms of low testosterone unaddressed.

This variability can be attributed to differences in metabolism, body composition, androgen receptor density/sensitivity and hormonal balance among individuals. Therefore, it is crucial to monitor testosterone levels through bloodwork after initiating TRT. This allows for the adjustment of the dose to fall within the optimal range for each individual, ensuring effectiveness while minimizing the risk of side effects.

Frequency of Administration: Avoiding Peaks and Troughs on TRT

The frequency of testosterone administration is another critical factor in the effectiveness of TRT. Traditional protocols that rely on less frequent injections or dosing schedules can lead to significant fluctuations in testosterone levels. These fluctuations may result in periods where testosterone levels are too high, followed by intervals where levels drop too low, causing a return of symptoms such as fatigue, mood disturbances, and decreased libido.

More frequent dosing schedules, such as twice-weekly injections, help maintain more stable testosterone levels, reducing the hormonal roller coaster effect and providing a more consistent alleviation of symptoms. Some men may require a smaller dose but injected 3 x per week due to faster metabolisation of testosterone.

TRT Clinics & Overmedication

A common issue in TRT protocols is the overuse of additional medications, such as aromatase inhibitors (AIs) and human chorionic gonadotropin (HCG) - which are often prescribed at the initiation of TRT by clinics wanting to increase their bottom line.

While these medications can be valuable for addressing specific side effects during treatment, such as lowering estrogen due to elevated aromatase activity or fertility, their indiscriminate use can complicate treatment and should not be prescribed from the initiation of treatment. More-so these medications should only be used for a specific issue. ie HCG when sperm count is low and the patient is planning on having a child.

An aromatase inhibitor should generally only be used when serum estrogen levels are supra-physiological and causing negative side effects. Even then an investigation should be made into why excess aromatisation (conversion of testosterone to oestrogen) is taking place, and remedying the pre existing issue - such as high body fat levels, sleep apnea, alcohol consumption, fatty liver, TRT dose being too high, chronic inflammation, poor metabolic health and insulin resistance.

Overuse of AIs (aromatase inhibitors), for instance, can suppress estrogen levels too much, leading to joint pain, mood issues, and negatively impacting cholesterol profiles.

Similarly, unnecessary supplementation with HCG can make managing testosterone and estrogen levels more challenging, as many men anecdotally report estrogenic side effects when using HCG. And in addition to this, as mentioned earlier there is a lack of long term research on the concurrent use of HCG alongside TRT.

The Imperative of Individualised TRT Treatment Plans

Given the variability in how different individuals respond to TRT, creating a personalised treatment plan is paramount. This plan should be based on thorough initial assessment and regular follow-up blood tests to monitor hormone levels and adjust treatment as necessary. Individualising treatment takes into account not just the dosing and frequency of testosterone administration, but also the patient's overall health, symptoms, lifestyle factors, and treatment goals.

This individualisation is often referred to as ‘optimisation’ as it involves very slight dose titrations to find a dose where the patient achieves significant symptom alleviation without having significantly supra physiological serum testosterone levels.

How to see if TRT is needed

Patients with low testosterone generally present with symptoms such as: Low Energy / Fatigue, Low Motivation & Drive, Low Sex Drive, Low Mood, Mood Swings & Irritability, Poor Focus & Concentration, Brain Fog, Loss Of Physical Strength, Muscular Atrophy, Poor Sleep Quality and Erectile disfunction. Many patients do not have all the symptoms, sometimes they only experience a handful of them.

In any case it is imperative to discuss with the patient and find out how significantly the symptoms are impacting the quality of their life and in what areas. As this will provide more clinical information to evaluate whether TRT may be the right choice for them.

Pathology investigation

When investigating if low testosterone is the cause of the above symptoms, comprehensive blood work should be conducted to check serum testosterone levels, assess a patient’s overall health, check for contraindications to TRT, and also investigate FSH/LH levels to determine whether the hypogonadism (if present) is primary or secondary.

Total Testosterone, SHBG and Free Testosterone (on two separate days)

These tests measure the levels of total and free testosterone in the blood. Conducting the test twice helps establish a consistent baseline as levels can fluctuate by up to 30% on a daily basis.

Many men present with a ‘normal’ Total Testosterone level, however upon investigating Free Testosterone this can be quite low, indicating hypogonadism. It is imperative to check free testosterone levels and not just total testosterone. For many of our patients, when they have gone to a GP to discuss their symptoms, and ask to check their testosterone levels, the GP generally only tests Total Testosterone. If this level comes back normal, the doctor ends the hypogonadism investigation there and moves onto another potential cause, such as depression - which we have seen misdiagnosed hundreds of times based on the experience of some of our patients.

Luteinising Hormone (LH) and Follicle-Stimulating Hormone (FSH)

These tests determine if hypogonadism is primary or secondary. High-normal levels of LH/FSH can indicate primary hypogonadism, suggesting a problem with the testes. Low-normal levels tend to point toward secondary hypogonadism, indicating an issue with hormonal signalling from the hypothalamus or pituitary gland to the testes.


This hormone test helps detect hyperprolactinemia, a potential cause of low testosterone. If prolactin levels are significantly elevated, further investigation with a pituitary MRI may be necessary to rule out a pituitary tumor - which can cause low testosterone.

Full Blood Count (FBC)

This test identifies potential high red blood cell (RBC) count and hematocrit (HCT), the viscosity of blood. A high hematocrit (above 0.51) could be a contraindication for TRT, indicating increased risk for blood clotting. This is because for many men who start TRT, they notice a slight increase in this level. Starting with an already elevated HCT would likely cause this level to quickly exceed the top of the normal range and could result in adverse cardiovascular side effects.

Prostate-Specific Antigen (PSA)

This test helps identify potential issues with prostate health, which could contraindicate TRT. This is important to test prior to commencing TRT, as TRT may potentially cause existing prostate issues such as cancer to get worse - although the literature is somewhat mixed in this area, it is best to tread with caution.

Kidney Function Tests

Assess kidney health and determine whether kidney dysfunction could be a factor in low testosterone. This test also provides a baseline for overall kidney health before starting TRT. A man experiencing kidney disease or failure should not commence TRT until this is resolved.

Liver Function Tests

Liver health is crucial, as liver damage can lead to low testosterone. This test also offers a baseline assessment of liver health before TRT initiation. TRT should not be initiated if a patient is experiencing liver failure or in a current disease state - again this should be resolved before investigating if TRT is the right option.

Glucose and Cholesterol

These tests assess general health, as elevated glucose or cholesterol can contribute to various health issues. High glucose levels can also be a potential cause of low testosterone. Untreated or uncontrolled diabetes can also cause low testosterone.

Lifestyle Investigation

Before commencing TRT, a thorough investigation should be made to ensure the patient is suitable for TRT. This is to also get an in-depth look at the patients current lifestyle, and whether they need to make drastic changes to improve their health.

Previous Conditions

Investigate any history of illnesses, surgeries, or significant health events, especially those related to testicular function, endocrine health, or chronic diseases.

Current Conditions

Identify ongoing health issues such as diabetes, cardiovascular diseases, or prostate conditions. Ensure these are being managed adequately by their doctor.

Family History

Look for genetic disorders or other inherited health conditions that might impact testosterone production.

Current Medications

Review all medications the patient is currently taking, including doses and timing. This should include prescription drugs, over-the-counter medications, and supplements.

Previous Substance Use

Document any history of opiate use, recreational drug use, or anabolic steroid/SARM use.

Contraindications to TRT

Untreated sleep Apnea:

Check for a history of untreated sleep apnea, which can be exacerbated by TRT. If a patient has sleep apnea but is not treating it (CPAP etc) then TRT should not be initiated until patient is compliant with device, as TRT will likely worsen the sleep apnea, and lead to further health ramifications from sleep apnea.

Prostate Health

Investigate any previous or current prostate issues, including benign prostatic hyperplasia (BPH) or prostate cancer.

Cardiovascular Risks

Identify untreated cardiovascular conditions, such as high blood pressure or heart disease.


Determine if the patient has untreated or poorly managed diabetes.

As you reach the end of this comprehensive guide, remember that understanding Testosterone Replacement Therapy is the first step toward reclaiming your vitality and wellness. With the knowledge you've gained from both rigorous peer-reviewed research and our extensive clinical experience with over 1,500 patients, you are now better equipped to decide if TRT is right for you.

Don't let low testosterone define your life's quality any longer. Consult with a TRT clinic to discuss your options and potentially embark on a journey to enhanced health, improved energy, and renewed strength. Take control of your health today—your best years may still be ahead of you

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