I have been running caffeine for a year and the honest summary is that the effect is smaller than the internet suggests and real.
The measured outcome and the hoped-for outcome are rarely the same thing in these threads.
There is a serious question about whether the studied form matches what is sold, and nobody in a thread can answer it.
How do you separate the compound effect from the routine around it?
Baseline first. Without a baseline the after picture is decoration.
Three questions kill most of the confidence in a thread like this: sample size, blinding, who paid.
Nobody has ever been talked out of a stack by a stranger on the internet.
How long before you can reasonably say something is or is not doing anything?
Read the methods section. It is the only part that says whether the conclusion is allowed to exist. Currently on caffeine myself.
Stupid question: how do you know whether what is in the vial matches the label at all?
Baseline first. Without a baseline the after picture is decoration. Same for me with caffeine, unfortunately.
Reconstitution arithmetic is only half the problem. The other half is what was in the vial.
Narrow conclusion, briefly right. Broad conclusion, interestingly wrong. I know which I keep choosing. A year in on caffeine and it lines up.
A plausible mechanism is not an outcome, and this class is the textbook example.
Read methods.