Fildena 50 mg contains sildenafil 50 mg and is generally prescribed for adult men with erectile dysfunction (ED)—difficulty getting or maintaining an erection adequate for sexual activity. For ED, 50 mg is the usual starting dose for many adults. A clinician may adjust it to 25 mg or 100 mg depending on effectiveness, side effects, age, other medicines, and health conditions. Typically: Take it about Fildena 50 mg before sexual activity. It can be taken with or without food; a high-fat meal can delay the onset. It doesn't increase sexual desire and requires sexual stimulation to work. Don't take it more than once in 24 hours. Fildena/sildenafil should not be used with nitrate medicines (such as nitroglycerin) or recreational “poppers,” because the combination can cause a dangerous drop in blood pressure. If you're asking because you're considering Fildena 50 as your first ED medication, I can explain what factors determine whether 25 mg or 50 mg is the safer starting dose.