Evodiamine

One of the principle, bioactive alkaloids of Evodia rutaecarpa.  Like capsaicin, evodiamine is a vanilloid receptor agonist, with thermogenic and (potential) anti-obesity effects.  Evodiamine may also have therapeutic potential, due to its anti-tumor and analgesic effects.

Evodiamine is often added to fat burners (purified or as a standardized extract of Evodia) to promote thermogenesis.  It’s alleged to invoke a “shivering” response, although this is strictly anecdotal.