Numerous older publications from the 1960s, 1970s, and 1980s suggested bacteria, crabs, and other unlikely sources to explain detection of hCG outside of pregnancy. We now have a better understanding of the various sources of hCG when a person is not pregnant. This is explained in Chapter 28, Positive hCG Tests: Causes Other than Pregnancy, as quiescent gestational trophoblastic disease, as false-positive hCG assays, and as sulfated pituitary hCG. From this chapter we understand that men and women can have positive hCG tests because of circulating heterophilic or interfering antibodies. These cause false-positive hCG results and explain some of the strange findings in non-pregnant individuals. We also now know that men and women with cancer normally produce the total hCG assay immunoreactive free β-subunit of hCG. Here we examine the evidence that shows that the pituitary gland normally produces sulfated hCG during the menstrual cycle and in menopause. This is a further cause of positive hCG results in non-pregnant individuals.