PMS-C is associated with increased appetite, craving for sweets, headache, fatigue, fainting spells, and heart palpitations. Glucose tolerance tests (GTT) performed on PMS-C patients during the luteal phase of their cycle show a flattening of the early part of the curve, whereas during the follicular phase (first half of cycle) their GTT is normal. Some studies have also shown a fourth-hour hypoglycemic response during the luteal phase. There is currently no clear explanation for this phenomenon, although an increased cellular capacity to bind insulin has been postulated. This appears to be hormonally regulated, but other factors may also be involved. For example, the cellular response to a high glucose load results in an increased affinity for insulin. Sodium chloride enhances insulin response to glucose ingestion, and decreased pancreatic magnesium levels result in increased secretion of insulin in response to glucose. All are possible mechanisms.

A deficiency of the prostaglandin PGE, in the pancreas and CNS may also be involved in PMS-C. PGE1 inhibits glucose induced insulin secretion in humans.