Leptin, an anorexigenic peptide produced by white adipose tissue, inhibits hypothalamic ES [99], and Ob/Ob mice, lacking leptin, over-activate the hypothalamic endocannabinoid signalling [99] and are affected by infertility due to hypogonadotropic hypogonadism [100]. Here, LEP is linked to hypogonadotropic hypogonadism.