Chloasma, oral contraceptives, and plasma immunoreactive beta-melanocyte-stimulating hormone.

Plasma immunoreactive beta-melanocyte stimulating hormone (beta-MSH) has been measured in patients taking a progestogen-only oral contraceptive and in patients taking combined estrogen-progestogen therapy, of whom some had chloasma. Plasma levels did not differ significantly from those in a group of age- and sex-matched controls. It is concluded that the pigmentation of chloasma is not due to increased plasma concentrations of immunoreactive beta-MSH.