13-OAHSA, a branched fatty acid ester of hydroxy fatty acids (FAHFAs), results from the esterification of oleic acid to 13-hydroxy stearic acid. It represents a significant component of the FAHFA family, most abundantly expressed in the serum of glucose-tolerant AG4OX mice that exhibit adipose tissue-specific overexpression of the Glut4 glucose transporter. Similar to other FAHFAs which are known to enhance glucose tolerance, stimulate insulin secretion, and exert anti-inflammatory effects, 13-OAHSA may play a pivotal role in managing metabolic syndrome and inflammation.