Fluorouracil
"My doctor found what he thought might be burgeoning skin cancer on my bald head. First time, he 'burned' them off with whatever he sprayed on my head. Next visit (way later on) he said the spots hadn't gone away. He prescribed "Carac" (fluorouracil) if I could afford it. Over $400/tube! But my insurance paid up to the $20 I had to pay, so I went for it. Four weeks of dabbing this stuff on my head, and the pre-cancerous spots are gone. During the treatment my head got all scabby and red. Had to buy some cheapo pillow cases because I would end up bleeding on them at night. I guess the scabs got rubbed off as I tossed and turned.  Anyway, I'm totally satisfied with the outcome and would recommend this cream to anyone who can afford it."