I can't imagine it worked (unless the active ingredient was cocaine!), but it's a wonderful idea.
Possibly this is chocolate for people who suffer chocolate migraines?

If I developed an allergy to chocolate I'd probably die of depression or something.
I woke up with a hideous migraine this morning and it's still lurking at the corners of my vision. Can I have some of this please?
o_O We're friends on tumblr. Hello. Fancy seeing you here! (The internet is a small place, LJ even more so.)
If your headache is caused by caffeine withdrawal then this would work.
When I get a migraine, I always reach the stage where I'll be ready to do just about anything to make the pain stop. Hiow I wish that this worked.
I really wish dark chocolate wasn't one of my migraine triggers. I'd totally try this.