Answer:
I am slim and tall many find me desirable and appealing they touch me and I give a false good feeling once I shine in splendor but only once and then no more for many I am to die for.
I hide in a dark tunnel awaiting my time. I can only be released by pulling back. Once released I may do unstoppable damage.
Marking mortal privation when firmly in place. An enduring summation inscribed in my face.
I fly when I'm born. I lie when I'm alive. I run when I'm dead. What am I?
I am an English word that is as long as I am valued.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?