Tadarise Black 80 mg contains tadalafil, tadalafil has a relatively long half-life of about 17.5 hours. A drug generally takes around 4–5 half-lives to be mostly eliminated, so tadalafil can remain in the body for roughly 3–4 days after a dose. However, 80 mg is far above the usual maximum recommended tadalafil dose of 20 mg for on-demand erectile dysfunction. A higher dose can increase the duration and severity of side effects, including low blood pressure, headache, dizziness, and prolonged erection. Important: Don't take another tadalafil/PDE-5 inhibitor (such as Cialis, Vidalista, sildenafil/Cenforce, or vardenafil/Filitra) while tadalafil is still in your system. Nitrates such as nitroglycerin are particularly dangerous with tadalafil; nitrate use generally needs to be avoided for at least 48 hours after tadalafil. If you've already taken Tadarise Black 80 mg, tell me when you took it and whether you've taken any other ED medicine or heart medicine, and I can help you assess the situation.