What the Evidence Says About Testosterone and Type 2 Diabetes
Key takeaways
- Testosterone helps with how the body uses energy and sugar. Low testosterone is more common in men who have type 2 diabetes than in the general adult population.
- For men with clearly low testosterone, treatment may help improve insulin sensitivity, body fat, muscle balance, and some markers of metabolic health. This is only in addition to usual diabetes care.
- Testosterone treatment does not replace diabetes medicines, healthy eating, or regular physical activity. It is not a primary treatment for type 2 diabetes.
- In women, testosterone is not used to treat diabetes. In some cases, it may be prescribed for specific symptoms, most often low sexual desire, and only under specialist care.
- Testing, prescribing, and follow-up must always be performed by a medical professional, with regular checks to ensure the treatment is safe and effective.
Why Testosterone Plays A Role In Metabolic Health
Testosterone is a hormone that does more than affect sexual health. In adults, it helps the body manage muscle, fat, and energy. These things are closely linked to metabolic health and blood sugar control.
Muscle mass and blood sugar use
Muscle is one of the primary tissues that uses sugar from the blood. Healthy testosterone levels help maintain muscle strength and size. When muscle mass drops, the body finds it harder to use sugar properly. This can lead to higher blood sugar levels and reduced insulin sensitivity.
Fat storage and insulin sensitivity
Low testosterone is linked with higher levels of visceral fat. This is fat stored deep in the abdomen around the organs. Visceral fat can cause long-term low-level inflammation, which makes insulin work less well and worsens blood sugar control.
Energy levels and movement
Testosterone helps support energy, motivation, and physical strength. When levels are low, people may feel more tired and less active. Lower activity levels can affect metabolism by reducing daily movement and muscle use.
Hormone balance and inflammation
Testosterone also affects other hormones and inflammation in the body. When hormone levels are out of balance, it can increase inflammation and affect how the body processes sugar and fat. Over time, this may contribute to conditions such as type 2 diabetes.
Because of these links, healthcare professionals may check testosterone levels in adults with type 2 diabetes, especially if symptoms like tiredness, muscle loss, or sexual problems are present.
How Testosterone And Type 2 Diabetes Are Linked
Testosterone levels and type 2 diabetes affect each other. Low testosterone can make metabolic health worse, and long-term diabetes can also lower testosterone levels. This means the relationship works in both directions.
Insulin resistance and hormones
Insulin resistance is a key part of type 2 diabetes. When testosterone levels are low, the body may not respond to insulin as well. This means the body needs to make more insulin to keep blood sugar levels steady. Over time, this can lead to poorer blood sugar control and extra strain on the pancreas.
Changes in muscle and fat
Low testosterone is linked with less muscle and more body fat, especially around the stomach. Less muscle mass makes it harder for the body to use blood sugar. Extra fat can worsen insulin resistance and may further lower active testosterone levels.
Long-term inflammation
Fat stored deep in the abdomen can cause ongoing low-level inflammation. This inflammation can block insulin from working correctly. It can also affect the body systems that control testosterone, creating a cycle where hormone problems and metabolic problems make each other worse.
How diabetes can lower testosterone
Type 2 diabetes can reduce testosterone levels in several ways. These include changes to blood vessels, nerve damage, and problems with hormone control. Age, excess weight, poor sleep, and some diabetes medicines can also play a part.
Understanding this two-way link helps explain why low testosterone is more common in adults with type 2 diabetes. It also shows why hormone balance may be considered part of overall medical care, rather than a single treatment on its own.
Evidence Overview: What We Know, And What Is Still Unclear
Research into testosterone treatment and type 2 diabetes is ongoing. Some findings are helpful, but others are still uncertain. The most straightforward way to understand this topic is to look at what we know with more confidence and what still needs more study.
Real-World Findings In Men With Type 2 Diabetes And Low Testosterone
Studies from Europe and the UK have looked at men with type 2 diabetes who also have confirmed low testosterone. Reports shared at major diabetes meetings show that testosterone treatment is linked with lower HbA1c levels over time in some men. There are also signs of weight loss, a smaller waist, and improved symptoms such as tiredness.
These results are helpful because they reflect real-life medical care. However, they are not the same as tightly controlled research trials, so the results must be interpreted carefully.
Clinical guidelines support careful use in the right men
European medical guidelines agree on key points. Testosterone treatment may be considered when symptoms match blood test results showing low testosterone. A doctor must always supervise treatment.
Guidelines stress the importance of safety checks before and during treatment. These include blood tests and prostate-related checks, as testosterone can affect red blood cell levels and prostate markers.
What Is Still Uncertain
Testosterone is not a primary treatment for diabetes.
Even when blood sugar levels improve in some men, testosterone is not used as a primary treatment for type 2 diabetes. Its main role is to treat confirmed testosterone deficiency. Any benefits for blood sugar are considered an added effect rather than the primary goal.
Audit findings are encouraging, but they do not replace the need for more substantial research when judging diabetes outcomes.
People respond differently
Not everyone sees the same benefits. Results can vary depending on body weight, how long someone has had diabetes, how low their testosterone levels are, and what other treatments they are using. Because of this, doctors focus on symptoms, safety, and overall well-being rather than just test results.
Long-Term Effects Need More Study.
The long-term impact on heart health and overall safety still needs careful monitoring. This is especially important for older adults and people with other long-term health conditions. Evidence in this area is still developing, and treatment decisions are made on an individual basis.
Evidence in women
For women, research does not support using testosterone to treat type 2 diabetes or to lower blood sugar. In the UK and Europe, testosterone may be prescribed to women only in specific situations, most often for low sexual desire, and usually under specialist care.
This reflects current guidance and the limits of the available evidence.
Testosterone Therapy In Men With Type 2 Diabetes
Testosterone replacement therapy, often called TRT, is prescribed for a condition known as male hypogonadism. This means a man has symptoms of low testosterone and blood tests that confirm low levels.
In men with type 2 diabetes, doctors may check testosterone levels because low testosterone and metabolic problems often occur together. This is more likely when symptoms continue over time, and there is weight gain around the waist.
When TRT may be considered
TRT is usually considered only when both of the following are present:
Symptoms of low testosterone
These may include:
- Low sex drive
- Erectile problems
- Ongoing tiredness
- Low mood or motivation
- Reduced strength or muscle size
- Reduced bone strength
Blood tests showing low testosterone
- Blood tests are usually taken in the morning
- Testing is repeated at least twice
- Results are reviewed alongside symptoms and overall health
This careful approach aligns with European medical guidance and helps avoid the misconception that TRT is a general treatment to boost metabolism.
How TRT may support metabolic health
When low testosterone is confirmed and treated, some studies and real-world reports show improvements in specific metabolic markers. These may include lower HbA1c levels and changes in weight and waist size in some men.
Extensive audit data presented at European diabetes meetings have shown that men with type 2 diabetes and low testosterone may see reductions in HbA1c over time when treated with TRT.
The key points for a UK and EU audience are:
- TRT is used to treat confirmed low testosterone.
- Any metabolic improvements are a possible secondary benefit.
- TRT is not used as a treatment on its own for type 2 diabetes.
What doctors usually check before starting TRT
Before treatment begins, doctors carry out health checks and plan regular monitoring. This usually includes:
- Measuring testosterone levels to check the response to treatment.
- Blood tests to monitor red blood cell levels.
- Prostate-related checks are appropriate, based on age and risk.
Ongoing follow-up is essential to make sure treatment remains safe and effective.
This approach reflects current European guidance and supports careful, medically supervised care.
Testosterone therapy in women and metabolic health
Women also produce testosterone, but in much smaller amounts than men. It helps with sexual wellbeing, muscle strength, and energy. However, how testosterone is used in women is very different from how it is used in men. This difference is essential for safety and for accurate medical information in the UK and Europe.
How testosterone works in women
In women, testosterone helps with:
- Sexual desire and arousal
- Keeping muscles strong and healthy
- Energy levels and general well-being
Testosterone levels naturally fall with age, especially during and after the menopause. This can affect quality of life for some women, but it does not mean that low testosterone should be assumed or routinely treated.
Testosterone is not a treatment for type 2 diabetes in women
Current UK and European medical guidance does not support using testosterone to treat type 2 diabetes in women.
Although testosterone affects muscle and fat, there is not enough evidence to show that testosterone treatment improves blood sugar control in women. Because of this:
- Testosterone is not prescribed to women to manage diabetes.
- Diabetes care in women focuses on proven treatments such as diabetes medicines, healthy eating, regular physical activity, and weight management.
This clear separation helps prevent confusion and supports safe, evidence-based care.
When testosterone may be prescribed for women
In the UK and EU medical practice, testosterone may be considered only in specific situations. The most common reason is:
- Ongoing low sexual desire that causes distress
This is usually considered only when other suitable treatments have not helped. A specialist does prescribing and follow-up.
When used, testosterone doses for women are much lower than those used for men, and treatment is carefully supervised.
Safety and monitoring for women
Women using testosterone need regular follow-up. Doctors will check:
- Whether symptoms are improving.
- Signs of side effects, such as acne or unwanted hair growth.
- Hormone levels should be kept within the normal female range.
Treatment is stopped if side effects appear or if there is no clear benefit.
Key takeaway for women with type 2 diabetes
For women living with type 2 diabetes, testosterone should not be seen as a treatment to improve blood sugar or metabolism. When prescribed, its role is limited to specific symptoms and is always guided by specialist care. This straightforward approach supports safe treatment and trustworthy medical advice.
|
Monitoring stage |
What is reviewed |
Why it matters |
|
Baseline assessment |
Symptoms, testosterone levels, blood count, and relevant health history |
Confirms suitability and identifies potential risks before treatment |
|
Early follow-up |
Symptom response, testosterone levels, side effects |
Ensures appropriate dosing and early detection of adverse effects |
|
Ongoing review |
Blood counts, symptom benefit, treatment tolerance |
Maintains long-term safety and effectiveness |
|
Treatment reassessment |
Overall benefit versus risk |
Determines whether therapy should continue or be adjusted |
Who May Be Assessed For Low Testosterone
Not everyone with type 2 diabetes needs to be tested for low testosterone. In the UK and Europe, doctors usually suggest testing only when symptoms and health signs point to a possible hormone problem. This helps avoid unnecessary tests and treatment.
Men who may be assessed
Men with type 2 diabetes may be considered for testosterone testing if symptoms continue over time and affect daily life, especially when there are metabolic risk factors.
Doctors may consider testing if a man has:
- Low sex drive or erectile problems
- Ongoing tiredness or low energy not explained by blood sugar levels
- Loss of muscle or reduced strength
- Increased belly fat despite efforts with diet and activity
- Low mood or poor motivation
- Poor diabetes control despite appropriate treatment
Testing is most useful when ageing, excess weight, medicines, poor sleep, or other health conditions cannot fully explain symptoms.
Women who may be assessed
In women, testosterone testing is more limited and used with extra care.
Assessment may be considered when:
- There is a long-lasting low sexual desire that causes distress
Symptoms have not improved with other suitable treatments. - The review is carried out by a clinician experienced in hormone care.
Testosterone testing in women is not used to check blood sugar control or manage diabetes. Other possible causes of symptoms are usually explored first.
Important points before testing
For both men and women:
- Symptoms matter as much as blood test results.
- A medical professional should guide testing.
- Self-testing or starting treatment based on symptoms alone is not advised.
Testing is the first step to understanding whether testosterone levels may be linked to symptoms. It does not mean treatment will automatically follow. This careful approach supports safe care and follows UK and EU medical standards.
Diagnosis and assessment process
Diagnosing low testosterone takes more than one blood test. In the UK and Europe, doctors follow a straightforward step-by-step process. This helps make sure results are accurate and that any treatment is safe. This is especially important for adults with type 2 diabetes, as symptoms can overlap with other health issues.
Clinical assessment comes first.
The process starts with a clinical review. A healthcare professional will look at:
- Symptoms that may suggest low testosterone
- Medical history, including how long someone has had diabetes and what treatments they use
- Body weight, waist size, and blood pressure
- Lifestyle factors such as sleep, alcohol intake, and physical activity
This helps doctors tell the difference between hormone-related symptoms and those caused by blood sugar control, excess weight, low mood, or medication side effects.
Blood tests for testosterone
Testosterone levels change during the day, so timing and repeat testing are essential.
Key points include:
- Blood tests are taken in the morning, usually before 11 am.
- Testing is repeated on a different day to confirm the result.
- Results are reviewed alongside symptoms, not on their own.
In some cases, doctors may also check other factors that affect how much testosterone is available in the body, especially if results are borderline.
Additional baseline checks
Before thinking about testosterone treatment, doctors usually carry out other checks to make sure it is safe. These may include:
- Blood tests to check red blood cell levels
- Checks linked to prostate health are where appropriate
- Liver function tests
- Assessment of heart and circulation risk
These tests help identify any conditions where testosterone treatment may not be suitable or may need closer monitoring.
Looking for reversible causes
Doctors also check for factors that can temporarily lower testosterone levels, such as:
- Excess body weight, especially around the abdomen
- Poor or untreated sleep problems
- Recent illness
Certain medicines
Treating or improving these factors may help testosterone levels recover without hormone treatment.
Making a diagnosis
Low testosterone is diagnosed only when:
- Symptoms match testosterone deficiency.
- Low levels are confirmed on repeat blood tests.
- Other possible causes have been considered.
This careful approach helps ensure that testosterone treatment, when used, is appropriate, focused, and supported by proper medical follow-up.
Potential benefits and realistic expectations
Testosterone therapy can offer meaningful benefits for some adults when testosterone deficiency is clearly diagnosed. However, outcomes vary between individuals, and expectations need to be realistic, particularly for people living with type 2 diabetes. Careful framing benefits help avoid misunderstandings and support informed decision-making.
Men with confirmed testosterone deficiency
In men who have symptoms and consistently low testosterone levels, testosterone therapy may lead to improvements in several areas over time.
Potential benefits include:
- Improved insulin sensitivity, which may support better blood glucose control in some men.
- Favourable changes in body composition, including increased lean muscle mass and reduced central fat.
- Improved energy levels and physical function.
- Improvement in sexual symptoms, such as libido and erectile function.
- Enhanced sense of well-being and quality of life.
It is important to note that improvements in metabolic markers, such as HbA1c, are not guaranteed and tend to be modest when they occur. Testosterone therapy works alongside, not instead of, standard diabetes treatments and lifestyle measures.
Women Under Specialist Care
For women, the expected benefits of testosterone therapy are different and more limited in scope.
When prescribed appropriately under specialist supervision, potential benefits may include:
- Improvement in sexual desire and sexual satisfaction.
- Subjective improvement in energy or well-being in selected individuals.
Testosterone therapy is not expected to improve blood glucose control, insulin resistance, or other diabetes related outcomes in women.
What Testosterone Therapy Does Not Do
For both men and women, it is essential to understand that testosterone therapy:
- Does not cure type 2 diabetes.
- Does not replace glucose-lowering medication.
- Does not eliminate the need for healthy eating, physical activity, and weight management.
- Does not produce immediate results, as changes typically occur gradually over months
Timeline and response
When it occurs, symptom improvement is usually assessed over several months. A lack of benefit after an adequate trial period may lead clinicians to reconsider or discontinue treatment.
Setting realistic expectations helps ensure that testosterone therapy, when used, is part of a balanced, evidence-informed approach to long-term health.
Testosterone Therapy Risks, Side Effects, And Monitoring
Testosterone therapy is a medical treatment. Like all treatments, it has possible benefits and risks. In the UK and Europe, safety and regular checks are a key part of how testosterone therapy is used in both men and women.
Possible Side Effects
Side effects can differ from person to person and depend on the dose and type of treatment. Commonly discussed side effects include:
- Acne or oily skin
- Mild fluid retention or swelling
- Changes in mood or sleep
- Skin irritation where gels or creams are applied
These effects are often mild, but they should be reported to a healthcare professional if they continue.
Effects on the blood
Testosterone can increase red blood cell production. In some people, this can make the blood thicker, which may increase health risks if not monitored.
Because of this:
- Blood tests are done before treatment starts
- Follow-up blood tests are done regularly.
- Treatment may be adjusted or paused if levels rise too high.
Prostate health in men
For men, prostate health is checked before and during treatment. This does not mean testosterone causes prostate problems. Monitoring helps doctors ensure treatment remains safe as men age. Decisions are based on personal risk factors and test results.
Heart and circulation health
There has been a careful study of testosterone therapy and heart health. Current guidance focuses on:
- Checking heart and circulation risk before starting treatment.
- Close follow-up for people with existing heart disease.
- Reviewing treatment if new symptoms appear.
This cautious approach reflects that research is still in its early stages.
Fertility considerations
Testosterone therapy can lower sperm production. It is not suitable for people who are trying to have a child. This is especially important for younger men and should always be discussed before treatment begins.
Monitoring during treatment
Regular monitoring is integral to care. This usually includes:
- Checking whether symptoms are improving.
- Measuring testosterone levels to ensure the dose is correct.
- Blood tests to monitor red blood cell levels.
- Reviewing any side effects.
Follow-up is usually done soon after starting treatment and then at regular intervals.
When testosterone therapy may not be suitable
Testosterone therapy may be delayed or avoided in people who have:
- Untreated health conditions that increase risk.
- Very high red blood cell levels.
- Certain hormone-sensitive conditions.
- Plans to start a family in the near future.
Decisions are made individually, balancing symptoms, possible benefits, and safety.
Forms of Testosterone Therapy
Below is a simple overview of how testosterone therapy is considered differently for men and women.
|
Area |
Men |
Women |
|
Typical reason for treatment |
Confirmed low testosterone with symptoms |
Selected symptoms under specialist care, most often low sexual desire |
|
Role in type 2 diabetes |
May help metabolic health in some men with confirmed low testosterone, as a secondary benefit |
Not used to treat diabetes or improve blood sugar levels |
|
Strength of evidence |
Moderate evidence from European studies in men with low testosterone |
Limited evidence, no proven metabolic benefit |
|
Typical dosing |
Replacement doses to restore normal male testosterone levels |
Very low doses, kept within the normal female range |
|
Monitoring focus |
Symptoms, testosterone levels, blood tests, and prostate checks were appropriate |
Symptoms and signs of excess testosterone, such as acne or unwanted hair |
|
Who is it suitable for |
Decided case by case, based on symptoms and confirmed low levels |
Very selective use, led by a specialist only |
Mobi Doctor offers adults access to qualified clinicians who can discuss hormone-related symptoms, assess treatment options, and determine suitability for treatment through an Online Consultation.
