You're talking about the study linked as "2006 study of 122 drugs", right? I can't find amphetamines in the tables or the text, what page is it on? (or was it maybe another paper linked in the article?)
I have a prescription for dexamphetamine, but I don't use/need it a lot, so I have some bottles left that are a bit old--not past the expiration date, which appears to be slightly less than 3 years (after the date of the recipe), on the bottle I'm currently looking at. So I was curious about the amphetamines in particular, and if it's just efficacy deteriorating a bit that's fine, because in my personal experience the effect (which is quickly and clearly noticeable) varies easily by 25% already, depending on so many other factors (like what/how much I eat, how well I slept, stuff like that).
I have a prescription for dexamphetamine, but I don't use/need it a lot, so I have some bottles left that are a bit old--not past the expiration date, which appears to be slightly less than 3 years (after the date of the recipe), on the bottle I'm currently looking at. So I was curious about the amphetamines in particular, and if it's just efficacy deteriorating a bit that's fine, because in my personal experience the effect (which is quickly and clearly noticeable) varies easily by 25% already, depending on so many other factors (like what/how much I eat, how well I slept, stuff like that).