The absence of side effects at 2.5mg isn't necessarily a sign it's not working - response varies significantly by individual, and some people feel only appetite change without the GI or sleep disruption. The clinical trial starting point for dose selection is a reasonable strategy; 2mg corresponds to the lower range where tolerability data is strongest. If you're seeing actual appetite reduction and scale movement even without side effects, that's the relevant signal. The comparison to someone who hit everything hard at 2mg and needed gym work to stabilize is a different physiological profile, not a better one - just a different response pattern.