Taking tadalafil tablets at 7pm and having sex the next afternoon is fine and effective. Tadalafil is used for erectile dysfunction, but it is important to note that penile erection can only be achieved through sexual stimulation and does not work without it. The drug shows significant improvement in erectile function, ability to maintain an erection for up to 36 hours after taking the drug. Taking tadalafil tablets at 7 p.m. the next afternoon is not yet more than 36 hours, within the effective range, so there will be drug effects. Adverse reactions often include headache, indigestion, increased heart rate, blushing and dizziness. It is forbidden to use it if you are allergic to the components of the drug, it is forbidden to use it while taking nitrate drugs, and it is used with caution in patients with heart diseases. It is recommended to find a doctor to check first, the drug needs to be used under the guidance of a professional doctor to avoid abusing the drug by yourself.