Capsaicin is the compound responsible for cayenne's heat, and it's studied for a short-lived thermogenic response — a brief, modest rise in how many calories the body burns at rest.
Trials also link it to a mild reduction in appetite at the next meal, though the effect is described as a nudge rather than anything dramatic.
In LipoPeak, it's paired with green tea as the two ingredients most directly tied to thermogenesis.
Where it sits in the formula: one of six named ingredients on the LipoPeak label, alongside Green Tea Leaf Extract, Gymnema Sylvestre, Raspberry Ketones.