Tadalafil can be taken on an as-needed basis or on a daily basis, and is usually effective after a few years of taking it. However, the exact efficacy varies from person to person due to each person’s different body type and response. Tadalafil can increase the blood flow to the cavernous body of the penis, and is mainly used clinically for the treatment of erectile dysfunction in men. This product can be taken as needed and usually takes effect 1 hour after dosing. The product can also be taken in low doses daily, and efficacy is usually observed within 3 months. It is effective in improving the symptoms of erectile dysfunction after a few years of administration, but the exact efficacy varies from person to person and should not be generalized. The frequent adverse reactions of this product include headache, flushing, indigestion, back pain, myalgia, etc. It is contraindicated for patients who are allergic to this product as well as patients taking nitrate drugs. It is recommended to take it under the guidance of a doctor and should not be used blindly. If the long-term use of the efficacy is not obvious, it is recommended to change the drug.