they can cause some serious problems, the amphetamines, with muscles and shit... Levo isomers especially, but any amphetamine can cause muscle twitching and symptoms of that sort. Even time down the line of not taking it.
You know, also malnourishment could be a huge reason after and during an amphetamine dose, or binge especially, or sometimes daily dosing as a medication i.e. correctly taking the shit.... can cause it too. I would take magnesium while taking amphetamines of any kind because they lower your magnesium levels and that can make you twitch, or even have brief palpitations. I noticed that magnesium helped mentally and physically nourish some of my lost neuro's and shit from taking amphetamine.
Valerian is good, and Passion Flower is good too. You should try Kava Kava tea (or capsules, but the tea works much better(the real tea, not that fake weak garbage you get at wal-mart, no I'm jk, its not too bad not really 'real' Kava tea though)) if you can find it around you. The depression is the part that will linger the longest of that drug w/d and usually does not manifest right away except a really heavy crash or something. Theres loads of good stuff like vitamins and minerals/supplements to help with your situation. What your feeling is normal too. It can take a few (or many) times of use to actually leave you with a particularly bad time of psychological dependency... the depression. Or for me it was anxiety, and depression as well I guess, but mainly anxiety of all types.
