This is something I found out the hard way. the other night I was walking through the house and didn't turn on the lights. I was using the plug in night lights and they turned out not to be enough. tripped and fell and caught the corner of a small table with my arm. The wound was just a scrape but being on blood thinners the blood kept coming. I tried the old tricks of cold water and ice they didn't work. that's when I remembered the styptic pencil. this worked like a charm. now it burned like !!!!!! but the blood stopped. covered it with a large bandage and went back to bed. Now some of you may already know all this but for those who don't I hope you never need it but if you do give it a try.