There is no way to increase the size of the testicles. If the testicles are small before the end of puberty, there may be a possibility of physiological enlargement. However, after the end of puberty, there is no possibility of secondary development, and there are no other medications or surgical methods to make them bigger again. Small testicular size is often caused by congenital testicular dysplasia or acquired testicular injury. Congenital testicular dysplasia is often accompanied by chromosomal and genetic abnormalities, and acquired testicular injury caused by factors including cryptorchidism, testicular torsion, mumps orchitis, and testicular trauma, all of which result in small testicular size and are irreversible.