Catabolic hormone

Catabolic hormones drive the breakdown side of metabolism: cortisol, glucagon, adrenaline and, indirectly, the counter-regulatory response to low blood glucose. They mobilise stored fuel and, in cortisol's case, can break down muscle protein for gluconeogenesis.

It matters because the category is routinely misused. Cortisol is essential — it wakes you up, mobilises fuel for training and controls inflammation — and it rises acutely with every hard session, appropriately. The problem is chronic elevation from unrelenting stress, poor sleep and excessive training load without recovery.

In practice, products marketed as cortisol blockers have essentially no evidence behind them, and blocking a hormone you need would be a poor goal anyway. Sleep, load management and stress reduction address the actual problem.