In very small doses and at the right times stimulants can work well for me, but if I overdo it or take them at the wrong time I can very much end up feeling sick, faint, or sleepy.
I am hypothyroid, as a preface to all this. So my body only makes a certain amount of "energy" per day anyway and if I'm undergoing extra stress then my energy stores are already taxed. So adding extra stimulants to the situation doesn't really help as it isn't addressing the problem. Good sleep is essential for me as not taking care of my body really sends me into a tailspin for days.
Coffee - I have my 1 - 2 cups in the morning but I sip it kinda slow usually over a few hours and not all at once. Often I'll have a little more in the evening.
I use Rhodiola in a tea blend and love it but a concentrated extract of it is generally too much for my system. It can make me feel pretty weird if I take it as a concentrate.
I have had sleepy reactions to herb blends that are supposed to be stimulants. I had tried for a while taking some supplement formulas that were supposed to help with keeping sugar energy in your system available for use instead of turning it to fat (thyroid problems tend to make you retain weight easier) and frequently they made me yawn uncontrollably.
I do indulge in the occasional Red Bull and when I drink that I couldn't get to sleep to save my life. Even 5 or more hours after drinking it it tends to disturb my sleep pattern for the night. I have to be really careful about when I drink it, if at all.
5 hour energy - I have had really mixed results with this stuff. I have occasionally used it while working really long/hard catering days. One day I drank one after lunch to try and avoid the afterlunch sleepies that always hit me especially when I haven't had a lot of sleep the night before. Well, that day it made me positively sick in addition to being tired. I felt awful and had to sit there on the cooler as still as possible for an hour or so until it backed off a little. Ever since then I've been really careful about those.
Our bodies are each really an incredibly unique chemistry experiment.....