Thank you for your question.
Penis size cannot be increased with medication. Sexual satisfaction is independent of the size of the penis. The most sensitive part of the vagina is the outer 2 inches. This means that your penis length of 5 inches will be OK to satisfy your partner. Very often when you look at yourself the penis appears shorter due to an optical illusion. The best way is to measure the length and circumference with a measuring tape when it is erect. You might be surprised. Try it.