You will probably be familiar with advertisements for pills, creams, ointments, supplements, contraptions, stretching exercises or surgery to increase penis size. Some sellers even offer a "money-back" guarantee. Unfortunately, these treatments are at best ineffective. Since they are usually sold illegally, they have not been medically approved and they could pose a threat to your health. Contraptions designed to stretch your penis are misadvertised - although penis pumps can help men with erectile dysfunction they do not increase the size of your penis. There is also no particular exercise which could cause permanent enlargement. It is possible to increase your penis size with plastic surgery. However, there is a risk of side effects and according to a study conducted in 2006, only 35% of men who underwent penis enlargement surgery were happy with the results.