Fildena 120 mg contains sildenafil citrate, a medicine used for erectile dysfunction (ED). It does not usually last all night.   Starts working: typically around 30–60 minutes after taking it (timing varies).   Duration: the effect commonly lasts about 4–6 hours, though some men may experience a shorter or longer effect. It does not mean you will have an erection for 4–6 hours; it helps you get an erection when you are *****ly stimulated. A 120 mg dose is higher than the commonly recommended maximum sildenafil dose (often 100 mg), and higher doses can increase side effects such as headache, flushing, dizziness, low blood pressure, vision changes, or a prolonged painful erection (priapism). Avoid sildenafil if you take nitrate heart medicines (such as nitroglycerin) or have been advised to avoid ***** activity due to heart problems. If you tell me your age, whether you have diabetes or high blood pressure, and what dose of sildenafil you have used before (if any), I can help you understand whether 120 mg is a reasonable option.