Sir is there any medicine which i can use to...

What is the normal size of the penis:
The normal size of the penis is from 8-18 cm in the case of an erection, if your penis is within this range, then the size of the penis in your case is considered normal, and there is no need to increase the size
can you increase your penis ?
- If you are at a relatively young age - before the age of 20 years -, penis size havent been determined yet , and  it will increase the size and length relatively with the nature of your body growth
- In the event that you are in your twenties or more,  the size of your penis in general has been determined , you will not be able to increase it manually or by medications 
So, how to increase the length of the penis if you are an adult?
- the only options to increase penis size in effective ways are the surgical options , which are :
1. there is a surgical option that may increase you penis size about 4-6 cm by cut out the internal tendons that connect pelvic area to your private area and leave bigger space to penis to increase 
2. there is a plastic surgery that increase penis size by implanting silicon implants in the upper areas of penis goes into the internal area of penis and it increase penis size around 6-8 cm
What are the pathological conditions that lead to shortening the size of the penis:
- Atrophy of penis and testicals due to low testosterone level
- Injuries to the penis or genital tract
what are the needed tests :
Initial clinical examination of the testicles and penis, and also a testosterone level test, along with an ultrasound examination of the genital area