The use of Testosterone Undecanoate Capsules as prescribed by the doctor usually does not cause serious harm to men, but if the drug is not used properly, there may be adverse reactions such as abnormal sperm and increased frequency of erection in men, which cannot be generalized. The main ingredient of Testosterone Undecanoate Capsules is Testosterone Undecanoate, which belongs to hormone drugs. It can be used to treat primary testicular hypogonadism, or secondary testicular hypogonadism and other diseases. If patients follow the doctor’s instructions to correctly use the drug treatment, generally will not cause harm to the body. However, if the drug is not used properly, it may cause patients to develop male sperm abnormalities, such as oligospermia or azoospermia, or symptoms such as feminization of the gynecomastia, increased frequency of penile erection, loss of libido, nausea, diarrhea, abdominal discomfort, and abdominal pain. The drug needs to be contraindicated for those diagnosed with prostate cancer, breast cancer, or those who are allergic to the ingredients of Testosterone Undecanoate Capsules. During the period of taking the drug, once the physical discomfort occurs, you need to consult a doctor in time, to clarify the cause of the disease, and actively take therapeutic measures.