PRL and hyperprolactinemia: While it is not universally observed, patients with hyperprolactinemia are prone to excessive weight gain (Creemers et al. 1991, Delgrange et al. 1999, Doknic et al. 2002, Baptista et al. 2004), and normalisation of prolactin levels using dopamine agonists is associated with weight loss (Greenman et al. 1998, Doknic et al. 2002, Galluzzi et al. 2005).