Nah I don't recommend them, what the other guys said. I mean, I'm big on coffee, but made sure to not become dependent on it and drink it out of enjoyment. Caffeine pills can have side effects if overdone and relied upon.
I'd suggest creatine monohydrate as a supplement to take, probably one of the most widely studied, with just an insane amount of benefits. Great for energy production and performance, muscle mass accretion, not addictive etc.
But in general I'm more of a fan of optimising your diet, and getting plenty of water in.