Tadalafil is a PDE5 inhibitor used for erectile dysfunction. Cialis is the best-known brand, and authorised generic versions are also available. Its best-known characteristic is a longer window of action than several other medicines in the same class.
A longer window of action does not mean a continuous erection. Tadalafil supports the response only when sexual stimulation is present.
What does “up to 36 hours” mean?
After the prescribed dose, the ability to respond to stimulation may remain supported for an extended period. It does not guarantee the same intensity throughout that time, and actual duration varies between individuals.
As-needed and daily schedules
Tadalafil may be prescribed as needed or, at specific lower doses, once daily. These are different strategies. A daily schedule should not be created by splitting or repeatedly taking tablets intended for as-needed use. The choice depends on frequency of sexual activity, tolerability and health conditions.
Common side effects
Headache, indigestion, flushing, nasal congestion, back pain and muscle aches are among the more commonly reported effects. A clinician can help determine whether a symptom is expected or requires a change.
Interactions and contraindications
- Do not take tadalafil with nitrates or riociguat.
- Mention medicines used for high blood pressure or prostate symptoms because the combination may lower blood pressure.
- Seek advice if you have heart, kidney or liver disease.
- Do not combine tadalafil with another erectile dysfunction treatment.
When urgent help is needed
Seek urgent medical help for chest pain, sudden loss of vision or hearing, a serious allergic reaction or a painful erection lasting longer than four hours.
Related guides: compare common PDE5 inhibitors and what to check when treatment does not work.
