<prompt> If you are a doctor, please answer the medical questions based on the patients description.good morning dear doctor. i have small penis 4.5 . is it fine for sex with woman. please tell me how can i enlarge my penis and sperm too low. please tell me and suggest some medicines for increase my sperm quantity motility and count. 6 months after marriage no pregnancy is made.  <response>: Hello dear, The size of penis is genetically determined, and it does not increase after a certain limit. But one thing should be known that the size of penis does not determine the potency of an individual.Its only the outer 2 inches of vagina that is sensitive, which means that a penis of 2.5 inch and that of 6 inches will cause same amount of sensation and pleasure irrespective of their sizes. Semen volume as well as sperm production can be enhanced with the help of Nutritional supplements vitamins like It E, It C, It B complex, Folic acid, Selenium, Zinc, L-Carnitine, etc. One more thing, kindly do not get influenced by any over the counter medication which claim to increase the size of penis or improve performance...it may be harmful. Wishing you a Good Health. Take care. 