Obesity is a major worldwide health problem. Current anti-obesity drugs are ineffective. Bariatric surgery is highly effective, but impractical to apply to the growing numbers of obese patients. These limited treatment options have fuelled tremendous interest in novel anti-obesity agents, but their development has been impaired by efficacy and safety issues. This talk will review the current stage of anti-obesity drugs in development, focusing on gut hormone-based therapies. The gastrointestinal tract is the body’s largest endocrine organ and releases a number of peptide hormones that can reduce appetite, including cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), oxyntomodulin and peptide YY (PYY). These hormones are sensitive to gut nutrient content and are released following a meal. They act on the appetite centres of the brain in the hypothalamus and brain stem to regulate food intake. Coordinated changes in gut hormone release are thought to modulate feelings of satiation and satiety. Anorectic gut hormones offer a potentially safe and viable option for the treatment of obesity. The potential utility of gut hormones has been dramatically improved by the development of gut hormone analogues with improved pharmacokinetics and efficacy. Additionally, specific combinations of gut hormones have been demonstrated to have additive anorectic effects. However, commandeering such peptidergic systems still poses a number of problems which need addressing. Recent research investigating the mechanisms by which the gut senses nutrients to stimulate gut hormone release may also reveal new targets for functional food ingredients to promote satiation and satiety. Gut hormones or the systems stimulating gut hormone release may prove effective targets for obesity therapies. Further work is required to elucidate the physiological mechanisms underpinning the effects of these hormones on appetite in order to optimise the design of such therapeutic agents.