I’ve had surgery done, and the surgeon that marked the incisions did use permanent marker, but not sharpie. There are toxic chemicals linked to various things from birth defects to cancer to liver failure if used often or frequently, or just many times over all. Maybe think twice before you uncap what’s inside being as it’s only nontoxic for it’s intended purposes- marking things on stuff that isn’t attached to a body. Just look at the other search results on google. A sharpie professional said not to use it on skin.