I have used it and the only side effect I had was shortness of breath. I found I could only take 1/2 every 3-4 days and it still worked well enough to keep most of my pain in check. My vestibular therapist takes it and said he had the ingredients checked out and the drugs not mentioned are prescribed by physicians many times for pain. I know there is no way I can take every day.Again I take every 3-4 days 1/2 pill.