11β-PGE2 is the C-11 epimer of PGE2. It is a moderate inhibitor of PGE2 binding to rat hypothalamic membranes with a Ki value of 53 nM.[1] 11β-PGE2 also stimulates bone resorption in rats at concentrations of 10-8 to 10-6 M which is similar to PGE2.2 11β-PGE2 inhibits PGE2 binding to the prostaglandin transporter protein with a Ki of 56 nM.[3]