Advanced TRT (Testosterone Replacement Therapy) Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGP

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What is the
Advanced TRT Blood Test?

Our Advanced TRT (Testosterone Replacement Therapy) Blood Test measures markers in your blood which can help you to monitor and manage your testosterone replacement therapy. 


What is
TRT?

Testosterone replacement therapy is a treatment for testosterone deficiency – also known as hypogonadism. It occurs in men when the body doesn’t produce enough testosterone and can lead to symptoms such as low sex drive and erectile problems, lack of energy and low mood as well as decreased muscle mass and bone density and increased body fat.


What’s included in the
TRT blood test panel?

The Advanced TRT Blood Test includes tests for a range of hormones (to monitor changes caused by testosterone supplementation), full blood count (to track red blood cell production) and other markers which are likely to be affected by treatment including liver and kidney function and cholesterol. It also includes a test for prostate-specific antigen (PSA), a protein which can be raised in cases of prostate cancer (although it can be raised in benign conditions as well).


What's included?

Cholesterol status
Clotting status
Diabetes
Hormones
Iron status
Kidney health
Liver health
Muscle health
Prostate
Proteins
Red blood cells
Thyroid hormones
White blood cells
Select profile for more information

Total cholesterol Cholesterol is an essential fat (lipid) in the body. Although it has a bad reputation it has some important functions, including building cell membranes and producing a number of essential hormones including testosterone and oestradiol. Cholesterol is manufactured in the liver and also comes from the food we eat. Although there are a number of different types of cholesterol, the two main components of total cholesterol are HDL (high density lipoprotein) which is protective against heart disease and LDL (low density lipoprotein) which, in high levels, can contribute to cardiovascular disease. Your total cholesterol result on its own is of limited value in understanding your risk of heart disease; high levels of HDL cholesterol can cause a raised total cholesterol result but may actually be protective against heart disease. Equally, you can have a normal total cholesterol level but have low levels of protective HDL cholesterol. The most important factors are how much HDL and LDL cholesterol you have, and what proportion of your total cholesterol is made up of protective HDL cholesterol. We give a detailed breakdown of the components of your total cholesterol in the rest of this cholesterol profile.
LDL cholesterol LDL cholesterol (low-density lipoprotein) is a molecule made of lipids and proteins which transports cholesterol, triglycerides and other fats to various tissues throughout the body. Too much LDL cholesterol, commonly called 'bad cholesterol', can cause fatty deposits to accumulate inside artery walls, potentially leading to atherosclerosis and heart disease.
Non - HDL cholesterol Your total cholesterol is broken down into 2 main components; HDL (good) cholesterol and LDL (bad). There are more types of harmful cholesterol in your blood than just LDL - these include VLDL (very low-density lipoproteins) and other lipoproteins which are thought to be even more harmful than LDL cholesterol. Non-HDL cholesterol is calculated by subtracting your HDL cholesterol value from your total cholesterol. It therefore includes all the non-protective and potentially harmful cholesterol in your blood, not just LDL. As such, it is considered to be a better marker for cardiovascular risk than total cholesterol and LDL cholesterol. The recommended level of non-HDL cholesterol is below 4 mmol/L.
HDL cholesterol HDL cholesterol (high-density lipoprotein) is a molecule in the body which removes cholesterol from the bloodstream and transports it to the liver where it is broken down and removed from the body in bile. HDL cholesterol is commonly known as 'good cholesterol'.
Total cholesterol : HDL The cholesterol/HDL ratio is calculated by dividing your total cholesterol value by your HDL cholesterol level. It is used as a measure of cardiovascular risk because it gives a good insight into the proportion of your total cholesterol which is good (i.e. high-density lipoprotein HDL). Heart disease risk tools (such as QRisk) use the cholesterol/HDL ratio to calculate your risk of having a heart attack.
Triglycerides Triglycerides are a type of fat (lipid) that circulate in the blood. After you eat, your body converts excess calories (whether from fat or carbohydrates) into triglycerides which are then transported to cells to be stored as fat. Your body then releases triglycerides when required for energy.
Platelet count Platelets or clotting cells are the smallest type of blood cell. They are formed in the bone marrow and are important in blood clotting. When bleeding occurs, the platelets swell, clump together and form a sticky plug (a clot) which helps stop the bleeding.
HbA1c Haemoglobin A1c (HbA1c), also known as glycated haemoglobin, is a longer term measure of glucose levels in your blood than a simple blood glucose test. Glucose attaches itself to the haemoglobin in your red blood cells, and as your cells live for around 12-16 weeks, it gives us a good indication of the average level of sugar in your blood over a 3 month period.
FSH Follicle Stimulating Hormone (FSH) is produced in the pituitary gland and is important for women in the production of eggs by the ovaries and for men for men in the production of sperm. In the first half of the menstrual cycle in women, FSH stimulates the enlargement of follicles within the ovaries. Each of these follicles will help to increase oestradiol levels. One follicle will become dominant and will be released by the ovary (ovulation), after which follicle stimulating hormone levels drop during the second half of the menstrual cycle. In men, FSH acts on the seminiferous tubules of the testicles where they stimulate immature sperm cells to develop into mature sperm.
LH Luteinising Hormone (LH) is produced by the pituitary gland and is important for male and female fertility. In women it governs the menstrual cycle, peaking before ovulation. In men it stimulates the production of testosterone.
Oestradiol Oestradiol is a female steroid hormone, produced in the ovaries of women and to a much lesser extent in the testes of men. It is the strongest of three oestrogens and is responsible for the female reproductive system as well as the growth of breast tissue and bone thickness. In pre-menopausal women, oestradiol levels vary throughout the monthly cycle, peaking at ovulation. In women, oestradiol levels decline with age, culminating with the menopause when the ovaries stop producing eggs. Low oestradiol can cause many symptoms associated with the menopause, including hot flushes, night sweats and mood swings. Low oestradiol can also cause osteoporosis.
Testosterone Testosterone is a hormone that causes male characteristics. For men, it helps to regulate sex drive and has a role in controlling bone mass, fat distribution, muscle mass, strength and the production of red blood cells and sperm. Testosterone is produced in the testicles of men and, in much smaller amounts, in the ovaries of women. Testosterone levels in men naturally decline after the age of 30, although lower than normal levels can occur at any age and can cause low libido, erectile dysfunction, difficulty in gaining and maintaining muscle mass and lack of energy. Although women have much lower amounts of testosterone than men, it is important for much the same reasons, playing a role in libido, the distribution of muscle and fat and the formation of red blood cells. All laboratories will slightly differ in the reference ranges they apply because they are based on the population they are testing. The normal range is set so that 95% of men will fall into it. For greater consistency, we use the guidance from the British Society for Sexual Medicine (BSSM) which advises that low testosterone can be diagnosed when testosterone is consistently below the reference range, and that levels below 12 nmol/L could also be considered low, especially in men who also report symptoms of low testosterone or who have low levels of free testosterone.
Free testosterone - calc Most testosterone circulating in the blood is bound to proteins, in particular SHBG and albumin; only 2-3 % of testosterone is free and available to cells. This test uses an algorithm to calculate the level of free or unbound testosterone in relation to total testosterone, SHBG and albumin.
Prolactin Prolactin is a hormone which is produced in the pituitary gland and plays a role in reproductive health. Its primary purpose is to stimulate milk production after childbirth, and in pregnant and breastfeeding women prolactin levels can soar.
Ferritin Ferritin is a protein which stores iron in your cells and tissues. Usually, the body incorporates iron into haemoglobin to be transported around the body, but when it has a surplus, it stores the remaining iron in ferritin for later use. Measuring ferritin levels gives us a good indication of the amount of iron stored in your body.
Creatinine Creatinine is a chemical waste molecule that is generated from normal muscle metabolism. Measurement of this is an indicator of the levels of other waste products in the body. Creatinine is also an accurate marker of kidney function, and may help in diagnosing kidney disease.
eGFR The estimated glomerular filtration rate (eGFR) assesses how well the kidneys are working by estimating the amount of blood filtered through the kidneys. The glomeruli are tiny filters in the kidneys responsible for removing waste products. If these filters do not do their job properly, kidney function can be impaired. The eGFR calculation is an estimate of actual glomerular filtration rate, calculated using your age, gender, ethnicity, and serum creatinine levels.
ALP Alkaline phosphatase (ALP) is an enzyme found mainly in the liver and bones. Measuring it can indicate ongoing liver, gallbladder or bone disease.
ALT Alanine transferase (ALT) is an enzyme which is mostly found in the liver, but is also found in smaller amounts in the heart, muscles and the kidneys. If the liver is damaged, ALT is leaked into to bloodstream. As ALT is predominantly found in the liver, it is usually an accurate marker for liver inflammation and can indicate liver damage caused by alcohol, fatty liver, drugs or viruses (hepatitis).
Gamma GT Gamma GT, also known as gamma-glutamyl transferase (GGT), is a liver enzyme which is raised in liver and bile duct diseases. It is used in conjunction with ALP to distinguish between bone or liver disease. Gamma GT is also used to diagnose alcohol abuse as it is raised in 75% of long term drinkers.
Creatine kinase Creatinine kinase (CK) is an enzyme which is necessary for muscle function and is found in the heart and skeletal muscles as well as other tissues. It signifies muscle cell damage and death and is measured to diagnose and monitor muscle damage. CK levels tend to be higher in people with greater muscle mass.
PSA - total Prostate Specific Antigen (PSA) is a protein which is released into the blood by the prostate gland. Prostate cancer can raise PSA levels but a PSA test in isolation is not to be relied upon to diagnose prostate cancer, as levels can be raised in benign prostate disorders (a false positive). There is also the potential for PSA levels to be normal despite the presence of prostate cancer, this is called a false negative.
Total protein Total Protein represents the sum of the proteins albumin and globulin in your blood. Albumin and globulin have a range of functions including keeping blood within vessels, transporting nutrients and fighting infection. Abnormal levels can indicate malnutrition as well as a liver or kidney disorder.
Albumin Albumin is a protein which is made mainly in the liver. It helps to exert the osmotic pressure which holds water within the blood. It also helps carry nutrients and medications and other substances through the blood and is important for tissue growth and healing. Albumin also carries hormones around the body, therefore measuring the amount of albumin in the blood can help us calculate how much hormone is available to your tissues.
Globulin Globulin is an umbrella term for a set of different proteins that the immune system and the liver produce. Certain globulins bind with haemoglobin while others transport metals, such as iron, in the blood. Additionally, there is a certain type of globulin known as an immunoglobulin, (another name for an antibody) which helps to fight infection in the body.
SHBG SHBG (sex hormone binding globulin) is a protein which transports the sex hormones (testosterone, oestrogen and dihydrotestosterone (DHT)) in the blood.Hormones which are bound to SHBG are inactive which means that they are unavailable to your cells. Measuring the level of SHBG in your blood gives important information about your levels of free or unbound hormones which are biologically active and available for use.
Haemoglobin Haemoglobin is a protein in red blood cells which carries oxygen around the body and gives the blood its red colour. This test measures the amount of haemoglobin in the blood and is a good measure of the blood's ability to carry oxygen around the body.
Haematocrit HCT (haematocrit) measures the amount of space (volume) within the blood that is taken up by red blood cells.
Red cell count Red Blood Cell (RBC) Count analyses the number of red blood cells in the blood. Red blood cells carry oxygen from the lungs to the rest of the body, where it can be used to fuel energy processes such as movement and respiration. They also carry carbon dioxide produced from cells back to the lungs so that it can be exhaled.
MCV MCV (mean corpuscular volume) reflects the average size of your red blood cells. This is important to measure, as it can indicate how much oxygen your cells are likely to be transporting around the body.
MCH MCH (mean corpuscular haemoglobin) measures the average amount of haemoglobin contained in one of your red blood cells.
MCHC MCHC (mean corpuscular haemoglobin concentration) is the average concentration of haemoglobin in your red blood cells. Haemoglobin is a molecule which allows red blood cells to transport oxygen around the body.
RDW Red blood cell distribution width (RDW) indicates whether your red blood cells are all the same size, or different sizes or shapes. Normally cells are fairly uniform both in size and in shape, but some blood disorders may cause your red blood cells to form in abnormal sizes. This test measures the difference between the largest and the smallest red blood cell.
TSH Thyroid stimulating hormone (TSH) is produced in the pituitary gland in order to regulate the production of thyroid hormones thyroxine (T4) and triiodothyronine (T3) by the thyroid gland. If thyroid hormones in the blood are low, then more TSH is produced to stimulate the thyroid gland to produce more of them. If thyroid hormone levels are high, then the pituitary produces less TSH to slow the production of thyroid hormones. If TSH is too high or too low, it normally signifies that there is a problem with the thyroid gland which is causing it to under or over produce thyroid hormones. Sometimes a disorder of the pituitary gland can also cause abnormal TSH levels.
Free T3 Triiodothyronine (T3) is the more active of the two thyroid hormones produced by the thyroid gland. Most T3 is bound to protein in the blood. Free T3 measures the level of T3 that is free, or unbound to protein, and is available to regulate metabolism.
Free thyroxine Thyroxine (T4) is one of two hormones produced by the thyroid gland. It works to speed up the rate of your metabolism. Most T4 is bound to carrier proteins in the blood - it is only the free, or unbound, T4 that is active in the body, which is measured in this test. Free T4 is the less active of the two main thyroid hormones. To have an impact on your cells it needs to convert to the more active T3 when your body needs it.
White cell count White Blood Cell (WBC) Count measures the number of white blood cells in the blood. White blood cells are key to your body's immune system. They fight infections and protect your body from foreign invaders such as harmful germs and bacteria. Additionally, they produce many antibodies and memory cells to protect you from further infections with the same germ.
Neutrophils Neutrophils are the most abundant type of white blood cell in the body and are responsible for helping your body fight infection. When a germ is initially detected by the body, neutrophils are the defence system which go out and attack the germ before any of your other white blood cells. When neutrophils are low you can be more vulnerable to illness and infection.
Lymphocytes Lymphocytes are a type of white blood cell which fight bacterial and viral infections. They are the subset of white blood cells involved in the more specific response to infections, which can identify and differentiate between different foreign organisms that enter the body. As well as fighting infection, they produce antibodies and memory cells to help to prevent future infections from the same germ. Lymphocytes include T cells, B cells and natural killer cells.
Monocytes Monocytes are a type of white blood cell that surround and destroy germs and dead or damaged cells from the blood. The heat and swelling that you feel when a body part is inflamed, for example after a cut on your finger, is caused by the activities of these cells.
Eosinophils Eosinophils are a type of white blood cell that are responsible for removing parasitic infections and regulating inflammation to mark an infected site. They also play a role in allergy and in asthma.
Basophils Basophils are a type of white blood cell that protect your body from bacteria and parasites such as ticks. They also play a role in allergic reactions.

How to prepare
for your test

Special instructions

Prepare for your Advanced TRT (Testosterone Replacement Therapy) Blood Test by following these instructions. Please take your sample before 10am. Avoid heavy exercise for 48 hours beforehand. Please avoid ejaculating for 48 hours prior to this test. Avoid heavy exercise for 48 hours beforehand. Avoid fatty foods for eight hours before your test, you do not need to fast. Hormonal contraception can affect the results of this test. Taking a break from this and waiting for your periods to restart before your blood test will give more accurate results. Avoid taking your sample from a finger used to apply hormone gels/pessaries/patches in the past 4 weeks. Use gloves to apply these. You should take this test before you take any medication or vitamin/mineral supplements. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed. If you are a woman take this test two to five days after the start of your period, ideally on day three. It can be taken any time if you do not have periods.


Frequently asked questions

What does TRT mean?

TRT stands for testosterone replacement therapy. It is a form of treatment for men with testosterone deficiency who are also experiencing symptoms of low T. These include reduced sex drive, problems maintaining an erection, low mood, loss of muscle mass and gaining body fat. It involves taking exogenous testosterone (testosterone which is not produced naturally in the body), either in the form of a gel, tablet or by injection.

Why do I need to test before and during TRT?

Taking testosterone supplements can significantly influence other processes in your body – notably hormone and red blood cell production, but also liver and kidney function and cholesterol levels. It is important to test before starting TRT to establish your normal levels for these markers and then again during treatment to monitor the effects of supplementation.

How often should I test during TRT?

We recommend that you test before your TRT begins and then again 6 months later to monitor the effects of treatment.

How can I reduce my haematocrit level on TRT?

There are various ways to reduce haematocrit while on TRT including giving blood, lowering your dose or changing to a topical cream or gel. If you want to donate blood, please do so under medical supervision and ensure that your haematocrit is within acceptable levels for the donation centre.

Will my fertility improve again after TRT?

In most cases sperm count and quality recovers to previous levels once treatment has finished. This process can take time though and depending on the duration and dose used in treatment it may take 12 months or more to get back to normal. In some cases TRT permanently impacts fertility which may limit the ability to conceive in future.


Will TRT affect my fertility?

 

A common side effect of TRT is low sperm count or infertility (the inability to conceive). Taking testosterone medication or supplements can change the levels of other hormones circulating in the body – in this case it can supress the release of LH and FSH by the pituitary gland, leading to decreased sperm production.  Infertility caused by TRT is usually reversible. This TRT profile tests for various male reproductive hormones (including FSH, LH and prolactin) to help you monitor the effects that treatment may have on your fertility.

 

Is TRT a risk for prostate cancer?

 

While current research indicates that TRT is unlikely to increase the risk of prostate cancer caution is still advised, particularly for men who already have prostate cancer. We recommend having a physical examination of your prostate gland before commencing TRT and monitoring your prostate-specific antigen (PSA) levels during your treatment. However, you should be aware that there are shortcomings in testing PSA. For more information on testing PSA, read our helpful medical guide, what is PSA and should I test it?

 

Does this test tell me if I can take TRT?

 

TRT can have a positive, life-changing effect on men with low natural levels of testosterone, but it is not appropriate for everyone.  This test will confirm if you have low testosterone, but you will also need to show symptoms of testosterone deficiency to be eligible for treatment. The British Society for Sexual Medicine recommends that treatment is not given to men with certain stages of prostate cancer, breast cancer, high haematocrit (the percentage of red cells in your blood), severe chronic heart failure or an active desire to have children. This profile contains tests for haematocrit and for prostate-specific antigen (PSA), a protein which can be raised in cases of prostate cancer.  It can also be raised in benign conditions too.


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