Tadalafil is a selective and reversible inhibitor of cyclic guanosine phosphate specific phosphodiesterase, which is commonly known as a drug for the treatment of male erectile dysfunction. The main mechanism of action is that when sexual stimulation leads to local release of nitric oxide, specific phosphodiesterase 5 is inhibited by tadalafil, resulting in increased levels of guanosine cyclophosphate in the penile corpus cavernosum, leading to smooth muscle relaxation and blood flow into the penile tissue to produce an erection. In the absence of sexual stimulation, tadalafil will not have any effect. Therefore, the indication for tadalafil is for the treatment of male erectile dysfunction and sexual stimulation is required to enhance the product’s effectiveness. Tadalafil should not be used in women. In addition to this, the drug can enhance the antihypertensive effect of nitrates such as nitroglycerin, isosorbide nitrate, and isosorbide mononitrate, and should be contraindicated in patients who are taking any form of nitrates. This medication should be contraindicated in patients with myocardial infarction, unstable angina pectoris or transient angina pectoris during sexual intercourse, heart failure, refractory arrhythmias, hypotension or refractory hypertension, and in patients with cardiovascular disease. Finally, we remind you to use the drug carefully under the guidance of your doctor and pharmacist.