Tadalafil tablets are drugs for the treatment of erectile dysfunction in men and cannot be used in women. It usually takes 30 minutes after taking the drug to have an effect. Tadalafil is a long-acting class 5 phosphodiesterase inhibitor that allows blood to flow into the penis and produce an erection. It has a half-life of 17.5 hours and can be taken 30 minutes before sex and is effective at any time within 24 hours of taking it, but it must be sexually stimulated to take effect, and no sexual stimulation can achieve an erection. The maximum frequency of this drug is once a day, and it is best not to take it every day continuously, because it has not been determined whether it is safe to take it for a long time. In addition, it is strictly contraindicated in men who have had a myocardial infarction, unstable angina in the last 3 months, cardiac insufficiency, refractory arrhythmia, hypotension, stroke in the last 6 months, or who are allergic to Tatrafi.