INSIDER
- The reason tattoo ink stays in skin forever has to do with the immune system.
- When you get a tattoo, the ink flows down the tattooing needle into the middle layer of your skin, called the dermis.
- That creates a wound, which your body tries to heal by sending macrophages (a type of white blood cell) to the area.
- The macrophages swallow the ink in an effort to take the foreign particle away from the wound.
- But the pigment in the ink is too large for the macrophages to remove, so the macrophages - with the ink inside - end up stuck in the dermis.