The present invention relates to methods of identifying whether a candidate compound is a modulator of a G protein-coupled receptor (GPCR). In preferred embodiments, the GPCR is human. In other preferred embodiments, the GPCR is coupled to Gi and lowers the level of intracellular cAMP. In other preferred embodiments, the GPCR is expressed endogenously by adipocytes. In further preferred embodiments, the GPCR inhibits intracellular lipolysis. In other further preferred embodiments, the GPCR is a nicotinic acid receptor. The present invention also relates to methods of using a modulator of said GPCR. Preferred modulator is agonist. Agonists of the invention are useful as therapeutic agents for the prevention or treatment of metabolic-related disorders, including dyslipidemia, atherosclerosis, coronary heart disease, stroke, insulin resistance, and type 2 diabetes.