This is a brief explanation of what progesterone is. It is important to know what this hormone is to better understand what HRT is.
Progesterone (P4) is an endogenous steroid. It is involved in the menstrual cycle, pregnancy, and development of the embryo in humans and other species. P4 is also essential for implantation of the fertilized egg in the uterus.
It belongs to a group of steroid hormones called the progestogens. P4 is also crucial in the production of other endogenous steroids. These include the sex hormones and the corticosteroids (used to reduce inflammation and suppress the immune system.) It also plays an important role in brain function.
P4 is released by the ovaries. Similar to oestrogen, P4 levels can change, and this can contribute to irregular menstrual periods and menopausal symptoms.
P4 has several physiological effects that are amplified in the presence of oestrogens. Oestrogens, through oestrogen receptors (ERs), induce the expression of the progesterone receptor (PR).
High levels of progesterone can reduce sodium retention. This means that it has a role in preventing bloating. Progesterone withdrawal, on the other hand can cause bloating. This is one of the reasons why so many women experience bloating during menopause.
Click here for a more detailed explanation of the functions of P4 in the body.