Tadalafil Side Effects & Warnings

• Tadalafil can cause side effects, but they are usually mild and short-lived
• Most symptoms such as headache or flushing settle within a few hours
• Serious side effects are rare, and Tadalafil is generally well-tolerated when used correctly

Tadalafil is a medicine used to treat erectile dysfunction (ED) and, in some cases, benign prostatic hyperplasia (BPH). It works by relaxing blood vessels and improving blood flow to certain areas of the body, helping men achieve and maintain an erection when sexually stimulated.

As with all medicines, Tadalafil can cause side effects. Most people experience none or only mild effects, but it’s still important to know what to expect, how to manage them, and when to seek advice.

Tadalafil can cause side effects, particularly when you first start taking it, or after a dose increase.

Common side effects affect up to 1 in 10 users. These usually improve as your body adjusts.

Headache

This is the most common side effect of Tadalafil.

It happens because Tadalafil widens blood vessels – not only in the penis but throughout the body – which can change blood flow to the brain.

How long it lasts:

These side effects are usually mild and short-lived, resolving within a few hours.

What to do:

• Stay hydrated and avoid alcohol (Tadalafil and alcohol do not mix well)
• You can take mild pain relief such as paracetamol if needed
• If headaches are persistent or severe, speak to your pharmacist or doctor about trying a lower dose of Tadalafil.

Muscle pain

Tadalafil can cause muscle or back pain, particularly in the lower back or thighs.

This happens due to increased blood flow to muscles and minor changes in oxygen use within tissues.

How long it lasts:

Typically appears 12-24 hours after taking Tadalafil and settles within 48 hours.

What to do:

• Gentle stretching and over-the-counter pain relief may help
• If pain is severe or affects mobility, discuss alternative doses or treatments

Flushing

Flushing (a feeling of warmth or redness, especially in the face or neck) is a common response to the widening of blood vessels.

How long it lasts:

These side effects are usually brief – lasting 15-30 minutes after taking Tadalafil.

What to do:

• Avoid hot drinks or alcohol, which can worsen flushing
• It often becomes less noticeable with continued use

Nasal congestion

Tadalafil can cause blocked or runny nose because blood vessels in the nasal passages also relax.

How long it lasts:

These side effects are temporary, resolving within a few hours as the medicine wears off.

What to do:

• Use a saline nasal spray for relief
• Avoid decongestant tablets unless advised by a doctor, as they may affect blood pressure

Less common side effects affect fewer than 1 in 100 users and are generally mild. These can include:

• Dizziness or light-headedness
• Indigestion or heartburn
• Palpitations (awareness of heartbeat)
• Nausea
• Blurred vision or mild visual changes
• Fatigue

If any side effects become troublesome, stop taking Tadalafil and seek medical advice.

You should seek urgent medical attention if you experience:

• Chest pain or difficulty breathing
• A painful erection lasting more than 4 hours (priapism)
• Sudden loss of vision or hearing
• Signs of an allergic reaction (swelling, rash, or difficulty breathing)

These reactions are extremely rare but require immediate medical attention.

Tadalafil does not cause long-term or permanent side effects.

Most side effects wear off as the medicine leaves your system (within 36 hours).

There is no evidence that Tadalafil damages the heart, liver, or kidneys when used as directed.

However, prolonged misuse – such as exceeding the maximum recommended dose or using unregulated versions bought online – can increase the risk of complications.

If you take Tadalafil daily, your doctor may occasionally review your blood pressure, kidney function, and cardiovascular health to ensure it remains suitable for you.

If you’re experiencing mild side effects, it may help to:

• Take the medicine at the same time each day (for daily users)
• Avoid alcohol before and after taking a tablet
• Discuss lowering the dose with your doctor or pharmacist

If side effects persist, you can consider switching to a different treatment such as sildenafil (Viagra).

Both medications belong to the same class (PDE5 inhibitors) but are processed slightly differently by the body, meaning one may suit you better.

Further reading: Tadalafil vs Sildenafil: Key Differences

Because Tadalafil widens blood vessels, it can slightly lower blood pressure.

For most men, this change is mild and not noticeable.

However, you should use caution if you:

• Already take medicines for high blood pressure
• Use nitrates (such as GTN spray or isosorbide mononitrate)
• Take alpha-blockers for prostate or blood pressure problems

Combining these medicines can lead to a dangerous drop in blood pressure.

Your doctor or pharmacist will review your current medication list to ensure Tadalafil is safe for you.

Clinical studies have also shown that Tadalafil is safe for most men with stable heart disease, if it’s prescribed appropriately and not combined with nitrate medication.

Always check with a healthcare professional before starting treatment.

Do not take Tadalafil if you:

• Use nitrates (GTN spray, isosorbide) for angina or chest pain
• Have severe heart or liver disease
• Recently had a heart attack or stroke (within the last 6 months)
• Have low blood pressure or uncontrolled high blood pressure
• Have a history of vision loss due to optic neuropathy (NAION)
• Are allergic to Tadalafil or any of its ingredients
• Have mild to severe heart failure
• Have uncontrolled arrhythmias
• Have been advised to avoid strenuous activity

Caution is also advised in those with:

• Kidney or liver impairment
• Anatomical deformities of the penis
• Certain blood conditions that make prolonged erections more likely, such as sickle cell anaemia, multiple myeloma, or leukaemia

Always read the patient information leaflet before use and follow the prescribed dose.

Most side effects are mild, predictable, and short-lived, resolving without the need for medical intervention. 

Understanding what to expect can help you use Tadalafil confidently and safely. 

If side effects persist or you experience anything unusual, speak to your pharmacist or doctor – they can help you adjust the dose or explore alternative options.

How long do Tadalafil side effects last? 

Most Tadalafil side effects, such as headache or flushing, last a few hours at most. 

Because Tadalafil stays in the body for up to 36 hours, mild side effects can occasionally last a little longer, but they usually settle on their own. 

If you experience ongoing or severe side effects, stop taking Tadalafil and speak to a healthcare professional.

Can Tadalafil cause vision problems? 

Some people may notice mild, temporary visual changes, such as blurred vision or a blue tint to their sight. 

This is uncommon and typically short-lived. 

Very rarely, Tadalafil can cause sudden vision loss due to a condition called non-arteritic anterior ischaemic optic neuropathy (NAION). 

If you experience sudden vision changes, stop taking Tadalafil and seek urgent medical help. 

Is Tadalafil safe for people with heart problems? 

Tadalafil is generally safe for people with stable heart conditions, but it must be used with caution. 

You should not take Tadalafil if you use nitrate medicines or have had a recent heart attack or stroke. 

Always speak to your GP or specialist before using Tadalafil if you have any form of heart disease. 

Does Tadalafil affect fertility? 

There is no evidence that Tadalafil affects sperm quality or fertility in men. 

It simply works by improving blood flow to help achieve an erection – it does not influence hormones or sperm production.