Progesterone
Progesterone is produced mainly by a temporary structure in the ovary called the corpus luteum, which forms after an egg is released.
During pregnancy, the placenta also produces it in large amounts.
What progesterone does in the body:
- Prepares the lining of the uterus/womb (called the endometrium) for a possible pregnancy each month.
- If no pregnancy occurs, falling progesterone levels trigger the shedding of the uterine lining – in other words, our period.
- If pregnancy does occur, progesterone keeps the uterine lining intact and supports the early stages of pregnancy.
- It counterbalances some of the effects of oestrogen, helping to prevent the uterine lining from becoming too thick.
It is also important to know that progesterone also plays an important role:
- It has a calming effect on the nervous system and contributes to sleep quality.
- The oestrogen-progesterone balance plays a role in bone remodelling, preventing bone loss, and stimulating new bone formation.
When we think about oestrogen and progesterone, we usually think about how these hormones influence fertility – which is our ability to have children.
These are not ‘just’ reproductive hormones. They are not only essential for pregnancy, childbirth, and our menstrual cycles.
For women, it is important that we also recognise and understand that oestrogen and progesterone play crucial roles in our physiology and overall health. These hormones are essential for our bone health, brain function, cardiovascular health, and metabolic health.
There is also a deep connection between oestrogen, progesterone and the brain. When oestrogen and progesterone levels swings erratically and decline overall, the brain is directly affected. Our brains struggle to adapt to these swings.
My Menopause SA
Evidence-based menopause information for South African women.
Page last reviewed: 1 March 2026
Next review due: 1 March 2027