EDIT: changed "perhaps" to "I wish".
One could argue for "explain what risks are and which precautions we are and aren't taking" government regulation and in fact I had to sign a slip of paper saying that jumping out of plane might be dangerous. But do you really expect idiots to listen?
Two horny people might also have sex and pass HIV to each other. Unlike conservatives (marriage license) or liberals (MeToo consent form), libertarians like myself do not want to force them to sign a piece of paper first, though I think they should exercise due diligence. As a practical matter, I don't actually care if you have to sign a piece of paper before getting a vampire facial, it will not ruin the mood to the same degree. But how much difference would it actually make given all the numerous ways one can hurt themselves doing stupid things? If you try to regulate all of them, that would really be a totalitarian nightmare where government is constantly watching you and stopping you from living your life as you want.
No regulation prevents 100%, but they do help.