No, it's not chemically addictive. What E does is fuck with the way your brain "recycles" some of the dopamine that gets released into the brain. Basically, there's a membrane in the brain cells that can pick up dopamine that has been released, so that it can regulate how much is actually floating around out there, stimulating cells and whatnot, aside form controlling how much is actually released. When you take E, that membrane actually reverses function, flooding your brain with dopamine. That causes various effects, especially mood changes, since dopamine is a mood regulator. Of course, like all other neurotransmitters, it controls a whole fuckton of other shit too, which is why you need to take care that you don't overheat or exert yourself.
As for being chemically messed up, not really. The worst thing that can happen is that you may end up depleting your brain's supply of dopamine or severely reducing it to a level lower than you normally have when your not taking E. that can cause effects such as depression and such for a day or 2 after. However, that effect can be mitigated by taking 5-HTP supplements (can be found at any pharmacy). 5-HTP is the precursor to Dopamine, so by taking a supplement before rolling, you can mostly mitigate that, since by the time your done rolling, your body will have had enough 5-HTP to process to bring your dopamine levels more or less back to normal. You might be a bit low for a short time, but it nearly as much as if you hadn't taken 5-HTP. It's also suggested to take vitamin C with the 5-HTP, I believe it's supposed to help your body process it faster.
