The size of the penis does not normally grow after development has ended, and in the case of fully developed males there are generally no medications that can promote penis enlargement. If it is a child, you can use testosterone undecanoate and other drugs to treat it according to the specific situation as prescribed by the doctor. Testosterone undecanoate and other drugs can promote the development of the penis, suitable for the treatment of male children due to androgen deficiency caused by penile shortening, need to be taken in childhood. For mature male patients with short penis, the use of drugs is ineffective, can consider surgery to extend the penis. But need to go to the regular medical institutions. Patients who want to thicken and enlarge their penis are advised to go to a regular hospital, cooperate with the doctor to complete the relevant examinations to clarify the causes and avoid blind treatment.