One time, my idiot "friend" who was my dealer and not actually my friend (as I found out later) persuaded me to do a neck shot - both because of it supposedly being much stronger, and because most of my veins are really hard to hit. He said he'd do it for me, and he knew exactly what he was doing. For something so incredibly dangerous, he pretty much couldn't truly give a shit and was careless; he missed nearly the entire shot, and half my neck went numb and a great big lump had formed close to my carotid artery. When I found out later that night that this scenario very often leads to death if an abscess forms there and completely blocks blood flow to the brain, I almost went to his place to strangle him.
Don't trust people when they tell you things like this are safe - especially if they are addicts or dealers. In my experience, 99.99999999% of dealers are NOT true friends, and care about nothing except money.
EDIT: My advice to every IV user would be that if it gets to the point where you have essentially no choice but to start shooting in the femoral or jugular veins, you need to go get help and quit any way you possibly can. Use methadone, suboxone, or continue to use strong opiates any other way including IM if you absolutely can't live without them. If you have any value left for your life, this is beyond critical.