I have taken Vicodin on and off for around 10 years now. Sadly, it just doesn't seem to get the job done anymore, but that's more a result of my spinal pain getting worse than it is the medicine. That being said, it obviously has some nasty side effects that range from a bit annoying to wishing you'd have never picked up a bottle of it in your life. Addiction can result pretty easy, and dependence is an absolute given. You also begin to build up a tolerance fast, which means you are taking increasing doses of the drug to achieve relief. For what it is used for, it's a great compound. It works well for moderate pain, but there are other drugs out there that work just as well, if not better, without the large amounts of acetaminophen.