Understanding Tadalafil

Information about tadalafil and its use in treating erectile dysfunction

What is Tadalafil?

Tadalafil is a medicine belonging to a group of drugs called phosphodiesterase type 5 (PDE5) inhibitors. It is primarily used to treat erectile dysfunction (ED) in adult men. The medicine works by helping to relax the blood vessels in the penis, allowing blood to flow into the penis when sexually aroused.

Tadalafil is also used to treat the signs and symptoms of benign prostatic hyperplasia (BPH), a condition where the prostate gland becomes enlarged.

How Does Tadalafil Work?

Tadalafil works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). This enzyme breaks down a substance called cyclic guanosine monophosphate (cGMP), which is involved in regulating blood flow. By blocking PDE5, tadalafil helps maintain higher levels of cGMP, which allows blood vessels in the penis to relax and widen.

It's important to note that tadalafil only works when a man is sexually stimulated. The medicine does not cause an erection on its own and is not an aphrodisiac.

Common Brand Names

In the UK, tadalafil is available under several brand names, including:

  • Cialis (the original branded version)
  • Various generic versions simply called "Tadalafil"

Generic versions contain the same active ingredient and work in the same way as the branded version.

Formulations

Tadalafil is available as tablets in various strengths. Your clinician will determine which formulation and dosing regimen is appropriate for your individual circumstances. Only take tadalafil as prescribed.

Duration of Effect

One of the distinguishing features of tadalafil is its longer duration of action compared to some other medicines in the same class. This extended effect may be relevant to treatment planning and should be discussed with your healthcare provider.

Important Information

Tadalafil is a prescription-only medicine (POM) in the UK. This means you must have a valid prescription from a registered healthcare professional to obtain it. This website provides information only and does not prescribe or supply medication.

Contraindications and Cautions

Tadalafil is not suitable for everyone. Your clinician and pharmacist will assess whether it is appropriate for you. The patient information leaflet, NHS guidance, and your healthcare provider can advise on conditions and medicines that may interact with tadalafil, such as:

  • Certain cardiovascular conditions
  • Medicines such as nitrates
  • Serious liver or kidney problems
  • Certain eye conditions
  • Allergies to tadalafil or other ingredients

Always disclose all medicines you are taking and any medical conditions to your doctor or pharmacist before starting any new medication.

Speak to Your GP

If you're experiencing erectile dysfunction, it's important to speak with your GP or healthcare provider. They can help identify any underlying health conditions and discuss appropriate treatment options.

Visit NHS Information on ED

Further Reading

For more detailed information about tadalafil and erectile dysfunction, visit our articles section .

Sources: NHS; UK patient information leaflet for tadalafil; NICE guidance.

Last reviewed: 11 December 2025