Depends... how long has it not been healing? If it is more than a few days... you need to make sure to keep the wound clean so you do not get an infection. Some wounds heal from the inside out too. If it has been over a week, go to a doctor or med clinic and ask them to take a look. What kind of cut is it? Where is it located? How long has it been open? Those are the things a doctor will ask to figure it out.