The same drug and different effect

Can it be possible that the same pills from different pharmacies have different effect, for example when I took valium from one pharmacy, something like rxdrugs...and so on( I do not remember exactly the address) I though that I would never use this drug again as its effect was very unpleasant for me, but then my doctor ordered the same drug from drugshop247.com and it suited me greatly. I can not understand what it depends on...

Pills

yes it can if it is different brands,i take lithium and have to have the same brand each time,cos of the difference in the effect it has on me,hope this helps.

To orville3

Thanks for your reply,it's a pity that I did not pay attention to a brand at the first time...

I know what you are talking about

I had the same problem and more than that I had it several times till I found a proper place where to buy my meds. My cousine also used www.drugshop247.com and as far as I know she was satisfied with quality as well.