In our search for natural compounds that stimulate glucagon-like peptide-1 secretion, an extract from the leaves of Oparanthus teikiteetinii (Asteraceae) was found to increase significantly GLP-1 secretion in vitro in a model cell line (mouse intestinal STC-1 cells). The phytochemical investigation of this extract resulted in the isolation of two new dihydrobenzofuran derivatives (1-2) identified as (2R)-2-(prop-1-en-2-yl)-2,3-dihydro-1-benzofuran-5-ol (1) and (2S,3R)-2-(prop-1-en-2-yl)-2,3-dihydro-1-benzofuran-3,5-diol (2). Thirteen other compounds were isolated, including eight known dihydrobenzofuran derivatives (3-10), jasopyran (11), and four sesquiterpene lactones (12-15) including a new one, grandulin (15). Their structures were established mainly by NMR and HRESIMS analysis and by comparison with data reported in the literature. Tested on STC-1 cells at the concentration of 100 mu M, compounds 7, 11, and 12 increased GLP-1 secretion by 305, 218, and 156% respectively, compared to control cells, without affecting cell viability.