White boxes indicate specific drugs located next to the target upon which they are acting. Inside the white boxes green names stand for already approved drugs, whereas red names represent drugs in phase 1–3 development. The right hand panel summarises the neurotransmitters and pathways in the CNS in energy homoeostasis, whereas the left hand panel represents the mechanisms operative in the periphery. The intermediate area represents where the effects of both central and peripheral actions converge—namely, on the two main components of the energy balance equation: energy intake and expenditure. Most of the approved drugs are working centrally where stimulation of the POMC/CART pathway has anorexigenic effects, whereas the NPY/AGRP pathway exerts orexigenic effects. The interaction with the several receptors present in neurones of the hypothalamus determines the balance between orexigenic and anorexigenic effects. Most of the drugs tested in clinical trials are aimed at peripheral systems. Thus, thyroid analogues and β3 adrenergic agonists induce thermogenesis by activation of brown adipose tissue, thereby increasing energy expenditure. Enzymes involved in lipid metabolism, such as DGAT, FAS, MetAP2, and NQO1 are also being targeted. The gut microbiome and the regulation of bile acids represent further targets to combat obesity. The lipase and SGLT2 inhibitors favour energy loss by the gastrointestinal and renal elimination of fat and glucose, respectively. Agonism of pancreatic and intestinal hormones like amylin and GLP-1 has also been shown to be useful for weight loss. DGAT1=diacylglycerol O-acyltransferase aminotransferase 1. PexRAP=peroxisomal reductase activating PPARγ. FAS=fatty acid synthase. MetAP2=methionyl aminopeptidase 2. NQO1=NAD(P)H dehydrogenase: quinone oxidoreductase 1. SGLT2=sodium-glucose-linked transporter 2. AGRP=agouti-related peptide POMC=proopiomelanocortin C. CART=cocaine amphetamine-related transcript. GHSR=growth hormone secretagogue receptor. GLP1R=glucagon-like peptide 1 receptor. α-MSH=α-melanocyte-stimulating hormone. MCH1R=melanin-concentrating hormone 1 receptor. MC3/4R=melanocortin receptor type 3/4. 5HT2c=serotonin receptor type 2c.