Biomarkers

Target: Progesterone

Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestagens, and is the major naturally occurring human progestagen. It is the major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation, pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. During implantation and gestation, progesterone appears to decrease the maternal immune response to allow for the acceptance of the pregnancy. Progesterone decreases contractility of the uterine smooth muscle. The fetus metabolizes placental progesterone in the production of adrenal mineralo- and glucosteroids. A reduction in progesterone levels is possibly one step that facilitates the onset of labor. In addition, progesterone inhibits lactation during pregnancy. The drop in progesterone levels following delivery is one of the triggers for milk production in humans and other mammals. Progesterone, like pregnenolone and dehydroepiandrosterone (DHEA), belongs to an important group of endogenous steroids called neurosteroids. Neurosteroids are neuromodulators, and are neuroprotective, neurogenic, and regulate neurotransmission and myelination. Progesterone enhances the function of serotonin receptors in the brain, so an excess or deficit of progesterone has the potential to result in significant neurochemical issues. This provides an explanation for why some people resort to substances that enhance serotonin activity such as nicotine, alcohol, and cannabis when their progesterone levels fall below optimal levels. progesterone supports the normal development of neurons in the brain, and that the hormone has a protective effect on damaged brain tissue. It has been observed in animal models that females have reduced susceptibility to traumatic brain injury and this protective effect has been hypothesized to be caused by increased circulating levels of estrogen and progesterone in females. In addition to its role as a natural hormone, progesterone is also used as a medication, such as in menopausal hormone therapy.