Trodusquemine (MSI-1436) is a "first-in-class" highly selective non-competitive, allosteric inhibitor of PTP1B that can cross the blood-brain barrier to suppress feeding and promote insulin sensitivity and glycemic control. Trodusquemine is a naturally occurring cholestane that can be purified from the liver of the dogfish shark, Squalus acanthias, but it can also be manufactured synthetically by a fairly laborious process that requires several weeks. Trodusquemine has potential hypoglycemic, anti-diabetic, anti-obesity, and antineoplastic activities. Upon administration, trodusquemine selectively targets and inhibits PTP1B, thereby preventing PTP1B-mediated signaling. This prevents the dephosphorylation of the insulin receptor, which improves insulin signaling and insulin sensitivity, and decreases blood glucose levels. In susceptible cancer cells, inhibition of PTP1B causes a reduction of tumor cell proliferation.