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Erectile dysfunction (ED) and low testosterone can occur together, but they are not the same condition. While Testosterone Replacement Therapy (TRT) may improve libido and sexual wellbeing in men with genuine testosterone deficiency, restoring testosterone levels does not necessarily resolve problems achieving or maintaining an erection.
For some men, a clinician may also prescribe an erectile dysfunction medicine such as tadalafil, commonly known by the brand name Cialis. Tadalafil and TRT work in very different ways, which is why they may sometimes be used alongside each other following an appropriate clinical assessment.
The main things to understand before assuming erectile dysfunction is simply another testosterone problem.
Testosterone plays an important role in sexual desire, but an erection depends on much more than testosterone alone.
Healthy blood vessels, nerve function, psychological arousal, cardiovascular health and hormone balance all contribute to normal erectile function.
Erectile dysfunction may be associated with factors including:
Persistent ED does not automatically mean your TRT dose is too low. Someone can have satisfactory testosterone levels and still experience erectile dysfunction for completely separate reasons. Increasing testosterone without investigating the underlying cause may therefore be inappropriate.
Tadalafil belongs to a group of medicines known as phosphodiesterase type 5 inhibitors, or PDE5 inhibitors. PDE5 inhibitors are established treatments for erectile dysfunction.
Tadalafil supports the normal physiological process involved in achieving an erection rather than directly creating one.
TRT and tadalafil address different parts of sexual function. Correcting testosterone deficiency may improve symptoms such as reduced libido in appropriately selected men, while tadalafil primarily acts on the vascular mechanisms involved in achieving an erection.
TRT is intended to replace testosterone in men with clinically confirmed testosterone deficiency. Improvements in libido may occur, but TRT should not be considered a universal treatment for erectile dysfunction.
Tadalafil acts on the PDE5 pathway involved in penile blood flow. This means a clinician may consider it when erectile dysfunction persists despite appropriate management of testosterone deficiency.
Tadalafil should not automatically be viewed as another part of a TRT protocol or “stack”. Persistent erectile dysfunction can be associated with cardiovascular, metabolic, neurological, psychological or medication-related causes that may require investigation.
Tadalafil has vasodilatory properties and can produce a mild and temporary fall in blood pressure. For many appropriately assessed patients this is not clinically problematic, but it becomes especially important when other medicines that affect blood pressure are being taken.
Tadalafil can increase the blood-pressure-lowering effect of nitrate medicines. The combination is contraindicated because it can produce a potentially dangerous reduction in blood pressure.
If you use medication for angina or another cardiovascular condition, make sure your doctor or prescribing clinician knows exactly what medicines you take before using tadalafil.
Already taking blood-pressure medication? Tell your doctor or prescribing clinician before taking tadalafil. Some antihypertensive medicines can have an additional blood-pressure-lowering effect when used alongside tadalafil. This does not necessarily mean the combination cannot be used, but it needs to be considered as part of your individual medical assessment.
Like all medicines, tadalafil can cause side effects, although not everybody experiences them. Commonly reported effects include headache, indigestion, muscle aches, back pain, nasal congestion and flushing.
Headache is among the commonly reported side effects of tadalafil.
Dyspepsia or indigestion can occur after taking tadalafil.
Back pain, muscle aches and discomfort in the arms or legs can occur.
Some people experience facial flushing or a blocked or stuffy nose.
Tadalafil can also make some people feel dizzy. Because tadalafil can lower blood pressure, dizziness, light-headedness, weakness or fainting should be taken seriously, particularly if you already have low blood pressure or take medicines that affect it.
Serious adverse effects are much less common, but some symptoms require prompt or urgent medical assessment.
If you develop chest pain, tell healthcare professionals that you have taken tadalafil. This is particularly important because nitrate medicines normally used for angina can interact dangerously with tadalafil.
Erectile dysfunction should not always be viewed purely as a sexual performance problem. Healthy erectile function depends heavily on healthy blood vessels and adequate blood flow.
Persistent ED may occur alongside cardiovascular risk factors such as hypertension, diabetes, obesity, smoking and abnormal cholesterol. This is one reason recurrent erectile dysfunction is worth discussing with a GP or appropriately qualified healthcare professional rather than simply increasing testosterone or treating the symptom in isolation.
There is no single answer that applies to everyone. Some men with testosterone deficiency and erectile dysfunction may be prescribed tadalafil alongside TRT, while others may require a different approach depending on their cardiovascular health, medical history, medications and the underlying cause of their ED.
Tadalafil is a medication, not simply an addition to a TRT protocol. It has genuine clinical benefits, contraindications, medication interactions and possible side effects. If you experience persistent erectile dysfunction while receiving TRT, discuss it with the clinician responsible for your treatment.
UKTRT provides general educational information and is not a medical service. We are not doctors. The information on this page should not be used as a substitute for individual medical advice, diagnosis or treatment.
Do not start, stop or change prescribed testosterone, tadalafil, blood-pressure medication or any other treatment based on information on this website.
Tell your doctor or prescribing clinician about all medicines you take before using tadalafil, particularly medicines used for blood pressure, cardiovascular conditions or angina. Tadalafil must not be taken with nitrate medicines.
Further medical information about erectile dysfunction and tadalafil is available from:
Not necessarily. TRT may improve sexual symptoms in men with genuine testosterone deficiency, particularly reduced libido, but erectile dysfunction can have cardiovascular, metabolic, neurological, psychological and medication-related causes. Persistent ED should be appropriately assessed rather than automatically treated by increasing testosterone.
Some men are prescribed tadalafil while receiving TRT because the two treatments address different issues. Whether tadalafil is appropriate depends on your medical history, cardiovascular health, other medicines and the cause of your erectile dysfunction. It should be discussed with an appropriate healthcare professional.
Tadalafil has vasodilatory properties and can cause a mild and temporary reduction in blood pressure. If you already take medication for high blood pressure or another cardiovascular condition, tell your prescribing clinician before using tadalafil.
Tadalafil may be used alongside some antihypertensive medicines, but the combination can produce an additional reduction in blood pressure. Your doctor or prescribing clinician needs to know exactly what medicines you take so they can determine whether tadalafil is appropriate for you.
No. Tadalafil must not be taken with nitrate medicines because the combination can produce a potentially dangerous fall in blood pressure. Make sure healthcare professionals know you have taken tadalafil if you require treatment for chest pain.
Commonly reported side effects include headache, indigestion, back pain, muscle aches, flushing and a blocked or stuffy nose. Some people also experience dizziness.
Erectile function depends on blood flow, nerve function, psychological arousal and general health as well as hormones. High blood pressure, diabetes, cardiovascular disease, obesity, smoking, medicines and psychological factors can all contribute, so a normal testosterone level does not rule out other causes.
Do not change your prescribed TRT dose simply because you are experiencing erectile dysfunction. ED does not automatically mean testosterone levels are inadequate. Discuss persistent symptoms with the clinician responsible for your treatment so the underlying cause can be considered.