Parkinson's disease medications are developed and researched and prescribed by medical professionals. You are seeking ways to buy any old crap in a jar from dubious sources flogging 'cure alls' that will only offer the illusion of temporary relief while subjecting your body to all sorts of unknown side-effects. This creates a never ending cycle of dependency of buying god knows what from any online snake-oil salesman where you exacerbate side effects. All the while you are not dealing with the true underlying issues of fluency via tried and true non-chemical solutions. So, the drugs are the absolute worst course a stutterer can take.