Most peptides don't seem nearly as dangerous as insulin, luckily. Injecting insulin without medical supervision is a good way to give yourself hypoglycemia and die - blood sugar regulation is not something you want to mess with!
People don't seem to be regularly dying from peptides, at least not now.
I'd love to be able to make that statement with such confidence, but you just don't know. Literally no one has any clue what the long-term effect of injecting BPC-157 or what ever stupid well-marketed bullshit is the flavour of the week is, is.