Are there any stimulants that actually work and increase one's performance e.g. when running? Caffeine is an obvious one and it definitely works. I tried beta-alanine but it seems to do nothing except inducing itching at the fingertips. Tried some other popular supplements like citrulline, norvaline, l-arginine, but it's all shit (as expected).

So, except for caffeine are there any OTC stimulants that actually work?