Researchers in the University of Warwick’s Department of Biological Sciences have found that a hormone associated with obesity is actually also very active in the male genitals where it plays a key role in male fertility and may even influence the erection response in male sexual arousal. The research, published today (Tuesday 6th April 2004) in the “Journal of Clinical and Endocrinology and Metabolism” focuses on a protein called orexin. Orexin is named after the Greek word for appetite as previous researchers found it stimulates the human adrenal gland to produce cortisol which in turn can cause obesity. The University of Warwick researchers have now, for the first time, found clear evidence that orexin activity can be found in several areas of the male genitals where it has a more positive affect.