been on Vyvanse 70mg daily and 20mg afternoon Adderall IR boost for about 3 months....
after speaking with doc decided to try out the free concerta trial,
I took 54mg concerta yesterday and didnt work out as I expected, within 1hr I felt jittery, like a caffeine buzz, then felt really tired the rest day

is it fair to try out a new stimulant when another has been used? in another words did I experience amphetamine withdrawals rather than a concerta side effect?

well i've been on concerta one day and have alternated between tired flat and ****ed off so i would readily believe it's the concerta.

ritalin's half life is much shorter, so you will get a large up and then a hard come down in a much shorter time compared to adderall's longer lasting effect of duration and more subtle come down. This is why people that have used mph alot of times must dose higher when on the medication for a long time, it becomes less effective and when you increase the dosage unlike adderall the benefit is there but it does not increase the time or duration that the medication last for like adderall does.