I have a couple of these by the door for quick access, and another one in my hiking kit so I don’t forget to pack it. I’ve also given another set to family members. You can’t see the venom, but it’s clearly gone or mostly gone. No itching after the first or 2nd use of the tool. No welt the next day. Thankfully only mosquitoes so far, but cousin reported it worked well on a spider bite for her. Yes, some areas will sting a bit when using, and others just feel like strong suction. Guessing dependsSee full review