Oleuropein is a minor component of olives, olive oil and olive leaves.

Rat study: Oleuropein boosts testosterone, lowers corticosterone and increases protein retention in combination with high protien diet.
- Effects on testosterone, and other metrics, are most pronounced with a high casein diet.
- Boosts LH
- Boosts noradrenaline and adrenaline.
Relevance to humans unclear - corticosterone is part of the rat HPA feedback system, less so for humans