Male external genitalia develop under the action of androgens, which develop rapidly during puberty to essentially reach adult levels. Minors with abnormal testicular function can be treated with appropriate exogenous androgen supplementation under medical supervision. The size of the corpus cavernosum of the penis is usually related to genetic factors, on the other hand, minors can promote the development of the corpus cavernosum of the penis through appropriate physical exercise. The corpus cavernosum of the penis stops developing around the age of 18 and its size is relatively fixed. Adult penile corpus cavernosum can’t develop twice, there is no scientific basis for the secondary development of corpus cavernosum. Under normal circumstances, the length of the penis in the state of weakness is about 3 to 7cm, and the length of the penis after erection is about 10 to 16cm. When you suspect that the penis spongiosum is short, you should go to a regular hospital for a clear diagnosis.