Progesterone is often disregarded when we consider hormones, we mainly look at oestrogen and testosterone and forget about the incredible role that progesterone plays in a number of functions in the body and symptoms that irregular levels can create. Progesterone is considered the “feel good hormone” with its role in the production of GABA (a neurotransmitter) that helps promote better sleep and improves mood by creating a sense of relaxation and well-being. This detailed blog post is dedicated to educating us on all things progesterone, from where it is made, how low or high progesterone levels can affect us, and its role in our body- progesterone 101.
“Progesterone is like the baby sitter for oestrogen. So when stress causes progesterone to plummet, oestrogen goes wild. (and not in a good way).” – Dr Mindy Pelz.
Where is progesterone made?
Progesterone is mainly made in the ovaries by a temporary structure called the corpus luteum, which forms after ovulation (when an egg is released). This structure lasts about 14 days and produces progesterone under the influence of a hormone called luteinizing hormone (LH). Besides the ovaries, the adrenal glands, placenta (during pregnancy) and even the brain can also make small amounts of progesterone.
Unlike oestrogen, which needs multiple steps and different cell types to be made, progesterone is created in just two simple steps. First, cholesterol is turned into a substance called pregnenolone, and then it’s converted into progesterone.
How does progesterone affect our bodies?
- ✨ Sex hormone: Progesterone plays a key role in maintaining a regular menstrual cycle by working alongside oestrogen. It helps thicken the uterine lining in case of pregnancy and tells your body to shed that lining during your period if pregnancy doesn’t happen. It also helps with preparing breasts for pregancy (why women get tender breasts leading up to periods).
- ✨ Mood and brain health: Progesterone helps boost the production of GABA, a neurotransmitter that promotes relaxation, sleep, and a positive mood. When progesterone levels drop, GABA production decreases as well, which can lead to feelings of anxiety, sadness or depression. In perimenopause, lower progesterone levels often result in more frequent and intense mood swings.
- During pregnancy, higher levels of progesterone contribute to the sense of well-being that many women experience. However, after childbirth, the rapid drop in progesterone can lead to mood changes like the “baby blues” or postpartum depression.
- ✨ Muscles: Progesterone levels can affect muscle strength and performance. For example, during the menstrual cycle, progesterone levels fluctuate, some studies suggest that progesterone might have a relaxing effect on muscles, which can lead to a feeling of decreased muscle tension. This may contribute to a sensation of increased joint mobility during certain phases of the cycle. Progesterone also potentially influences muscle protein synthesis and impacts muscle strength/fatigue, especially in postmenopausal women.
- ✨ Weight: There are a number of ways that progesterone affects weight. Water retention, fat storage, metabolism and appetite and cravings. Progesterone can affect weight through its interaction with oestrogen. When hormone levels are ideal, progesterone and oestrogen have a lovely natural balance in our body, regulating the other’s effects. So while oestrogen promotes fat storage, progesterone allows our bodies to metabolise that fat. Progesterone also acts like a diuretic and helps with water loss and swelling. You can think of symptoms of water retention in menopause and post menopause when progesterone levels are low.
- ✨ Bone health: While many say that progesterone isn’t as vital or powerful in preserving bone mass as oestrogen, its role in balancing bone metabolism is crucial. Progesterone supports bone health by promoting bone formation (osteoblast activity) and working alongside oestrogen to maintain bone density.
Bonus benefits of progesterone?
- ✨ Immune system: Oestrogen and progesterone work in opposition to regulate immune function. Oestrogen enhances the immune system by promoting inflammation, while progesterone reduces inflammation by activating anti-inflammatory T-cells. Basically, progesterone helps “calm down” the immune response, maintaining a balanced immune system.
- ✨ Sugar control: Both oestrogen and progesterone play a role in regulating blood sugar by interacting with cells in the pancreas. So when these hormone levels fluctuate or drop significantly, like during perimenopause and menopause, the body’s ability to manage blood glucose becomes less efficient. This explains why blood sugar regulation can become more challenging during these times.
How progesterone levels fluctuate:
“Progesterone is not a minimalist hormone. It leans toward excess, toward velvet, toward a thickening of the blood. Under its spell, the womb’s endometrial mat goes from a thin brown covering to a thick crimson pile, a wild, expensive carpet, bedding fit for a king. No amount of money could buy a mattress with the thickness, the precision, the pure comfort that progesterone produces; here is where you started your first perfect sleep.” – Lauren Slater
In the menstrual cycle, At the start of the menstrual cycle (during your period), progesterone levels are low and stay that way through the follicular phase (when the egg is being matured). After ovulation, progesterone becomes the dominant hormone, produced by the corpus luteum (the structure left behind after the egg is released). Its levels peak in the middle of the luteal phase but drop if conception doesn’t occur, leading to the start of the next period.
Interesting fact: Progesterone can influence period symptoms by affecting mood, bloating and cramping. High progesterone in the luteal phase (before your period) can cause water retention, leading to bloating. It also slows digestion, which may contribute to constipation. Since progesterone interacts with brain chemicals like serotonin, low levels before menstruation can lead to mood swings or irritability.
What about during menopause? During perimenopause, progesterone levels fluctuate and gradually decline due to irregular ovulation- this can lead to symptoms like mood swings, anxiety, sleep disturbances and heavier or irregular periods.
In menopause, ovulation stops completely and progesterone production drops significantly, contributing to issues like poor sleep, low mood and bone loss. Since progesterone helps balance oestrogen- its decline may also lead to what some call “oestrogen dominance” in perimenopause before both hormones decrease in menopause. Some women use progesterone therapy to help manage symptoms like our Renewal Cream.
