Re: scar on penis head
Keep in mind that the head of the penis is extremely sensitive and is somewhat vulnerable compared to other parts of the body. In fact, if you are not circumcised, your body somewhat considers it an internal organ. When it is injured, it heals differently than other parts of the body.
Be careful with putting any types of treatments on your penis. Most items have warnings about using them in the genital areas. The skin on your penis is more sensitive than most parts of the body. It is more likely to be burned or irritated by chemicals that would be fine on other areas. It would probably be good to speak to either a dermatologist or a urologist to see what they think about Mederma on your penis. It may be harmless but if it is not, you really do not want to find out the hard way and make your bad situation worse.
Good luck to you