No. Penis growth medicines do not work. They are all a scam.
Your penis size erect is actually not much smaller than the average male penis. The average male penis is 13-14 cm when erect
Penis extenders can give you a slight increase in length (maybe an inch or so), but you have to be realistic with your expectations. It is not going to make you 2-3 inches bigger or give you more girth. It can only improve length and you have to use it 3-4 times a week for about 12 months to see any results. All the penis extender were taken off the market in the USA by the FDA because their claims of increasing penis length were never proved in a study. But there is a company called Andro Penis from Spain that sells the device that I think you can order on the internet. Hope this helps and please let me know if you have questions.