If the drug tadalafil does not work well you can try to increase the dose, if the effect is still not good after the increase then you can consider changing the drug, you can also add other therapies. Tadalafil is mainly used for the treatment of erectile dysfunction, the use of this product should be careful to follow the instructions of the method of taking the drug, take before sex, and after the use of the drug need sexual stimulation to make tadalafil effective. If the drug does not work well when taken correctly, the dose can be increased (up to 20mg). If the effect is still not good after reaching the maximum dose, the medication needs to be changed. Adverse reactions to tadalafil include dizziness, headache, indigestion, nausea, flushing, etc. Tadalafil is contraindicated in people who are allergic to tadalafil as well as in people who use nitrate drugs. Other commonly used drugs to treat erectile dysfunction are sildenafil, vardenafil, etc. Please change the drug under the guidance of your physician. In addition, it is important to develop good habits in daily life, and if necessary, seek psychotherapy or sexual life guidance, etc.