Funny that you mentioned didrex, I just filled a script two days ago took 100mg, yesterday and today and you're right they suck!!!. I would have better off with phetermine hydrochlroide (Fastin 37.5mg). I mean the fastin is suppose to weaker then the didrex. But in actuality they seem stronger and they are C-IVs. Didrex use to be a C-II drug, usually the stronger they are, the high classification, in terms of scheduling. The government recently lowered their classification C-III. I'm wondering can it be that in lowering the classification, the government had Upjohn somewhat change the structural formula of didrex to decrease it's addictive properties and at same time maintain it's appetite-suppresive properties. Or can it be that there has been bad batch shipped out accidentally or maybe it's that pink covering that actually hides the true white pill that within it, which is the benzphetamine in it's complete nature. Too many questions, answers anyone?