10-PAHSA is a newly identified endogenous lipid that belongs to a collection of branched fatty acid esters of hydroxy fatty acids (FAHFAs). It is a FAHFA in which palmitic acid is esterified to 10-hydroxy stearic acid. Among the FAHFA family members, PAHSAs are the most abundant in the adipose tissue of glucose tolerant AG4OX mice, which overexpress the Glut4 glucose transporter specifically in adipose tissue. As other FAHFAs improve glucose tolerance, stimulate insulin secretion, and have anti-inflammatory effects, 10-PAHSA may be a bioactive lipid with roles in metabolic syndrome and inflammation.