Are you a man, aged 18 years or over and experiencing erectile dysfunction (ED) i.e. difficulty in getting and/or maintaining an erection satisfactory for sexual performance?

Is this medication for you?

Are you allergic to Sildenafil or any of the ingredients of this medicine?

Are you already receiving treatment for the condition?

Has your doctor advised that you are not fit enough for any physical and/or sexual activity?

Do you feel very breathless or experience chest pain with light or moderate physical activity, such as walking briskly for 20 minutes or climbing two flights of stairs?

Have you had a heart attack or stroke within the last 6 months?

Do you have any other heart problems or are you under a doctor's care for any of the following:
Low blood pressure or uncontrolled high blood pressure
Unstable angina (chest pain), irregular heart beat or palpitations (arrhythmia)
A problem with one of the valves in your heart (valvular heart disease)
A problem where the heart muscle becomes inflamed and does not work as well as it should (cardiomyopathy)
Heart problems causing blood flow issues (e.g. left ventricular outflow obstruction, aortic narrowing) or severe cardiac failure

Are you taking nitrates (nicorandil or other nitric oxide donors e.g. glyceryl trinitrate, isosorbide mononitrate or isosorbide dinitrate) for chest pain?

Are you using drugs called "poppers" for recreational purposes (e.g. amyl nitrite)?

Are you taking riociguat or other guanylate cyclase stimulators for lung problems?

Are you taking ritonavir (for HIV infection)?

Are you taking any CYP3A4 inhibitors, e.g. saquinavir (to treat HIV infection), cimetidine (a heartburn treatment), itraconazole or ketoconazole (to treat fungal infections), erythromycin or rifampicin (antibiotics) or diltiazem (for high blood pressure)?

Are you taking any alpha-blockers, such as alfuzosin, doxazosin or tamsulosin, which are medicines to treat urinary problems due to enlarged prostate (benign prostatic hyperplasia) or occasionally to treat high blood pressure?

Do you have Peyronie's disease or any other deformation of the penis?

Have you ever had loss of vision because of damage to the optic nerve (such as non-arteritic anterior ischaemic optic neuropathy [NAION]) or have an inherited eye disease (such as retinitis pigmentosa)?

Do you have galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption?

Do you have previously diagnosed hepatic (liver) disease (including cirrhosis of the liver) or severe renal (kidney) impairment?

Do you have any of the following: sickle cell anaemia, multiple myeloma or leukaemia?

Do you have any bleeding issues (e.g. haemophilia) or have active stomach ulcers?