Polyphenol-rich onion extract alleviated hyperlipidemia in Sprague-Dawley rats’ livers by upregulating the low-density lipoprotein receptor (LDLR) and downregulating the 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase (HMGCR). Here, LDLR is linked to hyperlipidemia.