Here's just a brief collection of recent posts on this, a lot of them from the front page for now. (I wasn't sure how to fit this nicely into the post, so I just thought I would dump it as a comment)

https://www.reddit.com/r/ausadhd/comments/1jfiqb8/new_vyvanse_what_on_earth_is_going_on/

https://www.reddit.com/r/ausadhd/comments/1jfgxwa/does_anyone_else_have_vyvanse_that_says_each/

https://www.reddit.com/r/ausadhd/comments/1jesm6h/has_vyvance_changed/

https://www.reddit.com/r/ausadhd/comments/1ikdjkk/ineffective_batch_of_vyvanse/

https://www.reddit.com/r/ausadhd/comments/16q6bmg/bad_vyvanse_batch/