So you think that because of sounding difference between strength makes it stronger? Everything here is federal regulation with all prescription drugs. The pharmacy are all linked together and Dr shopping doesn't happen here. I have friends in the UK and I have studied much about it. I do know...
Being that I am allergic to opiates I don't take Percocet or anything else in that class. Since you claim that you know nothing about ghb, it's given to people over in UK as fibromyalgia treatment. Codeine isn't OTC here and is far stronger than tramadol.
Yes I know exactly what is prescribed and OTC in the UK so stay away from the ghb and that krokodil drug made from OTC codeine and paint thinner gasoline that's so popular in use
Do not self medicate anything beyond something that can be harmless and that includes massage therapist or chiropractor. Not all treatments are going to help someone else just because it worked out for one person. Underlying cause has to be established for effective treatment
I would strongly suggest that you see a psychiatrist and endocrinologist. Certain medications can aggravate symptoms causing the pain to be even worse. I would have to know what all labs have been done to rule out the obvious issues. Many hormonal imbalance can do just what fibromyalgia symptoms...
First off any drug you are given the first time is on an experimental basis. Hence why I said guinea pig. You have no way of knowing what effects any drugs are going to have the first time you take it