Taking testosterone undecanoate may cause impotence after stopping the drug. Testosterone undecanoate is an oral exogenous androgen that is primarily used to treat testosterone deficiency. However, taking testosterone undecanoate for a long period of time and then stopping the drug may lead to a decline in one’s own endogenous testosterone secretion function, and a decrease in spermatozoa, erectile dysfunction and even impotence may occur. Since testosterone undecanoate is mainly metabolized by the liver and affects the metabolism of triglycerides, people with cardiac, hepatic and renal insufficiency should follow the doctor’s instructions to use the drug with caution. And it is not recommended for patients who are allergic to the drug components of testosterone undecanoate, as well as patients with prostate cancer or breast cancer. The use of testosterone undecanoate, must be under the guidance of a professional doctor, on time and in accordance with the dosage, do not blindly use their own medication, so as not to cause adverse effects.