Progesterone – the overlooked hormone.

progesterone HRT

There is a big misunderstanding in women’s health around progesterone.

It is commonly side-lined as being “that hormone that thickens the uterus” but rarely are its other valuable functions mentioned.

Progesterone is needed for a woman to be healthy. It manages our mood, is essential in weight management, provides good sleep and most importantly it is our calming hormone.

These are the kind of words you commonly see attributed to progesterone, but the words fail to convey how life affecting it can be if we don’t have enough progesterone.

When we say that progesterone helps with mood, we mean that without progesterone we have no way of regulating our emotions. We will experience high levels of anxiety, lack of tolerance, anger and overwhelm.  Without enough progesterone women often say they feel like they are ‘going crazy’.

When we say that progesterone provides good sleep, we aren’t just talking about deeper sleep or being less restless. Women without enough progesterone commonly have terrible insomnia and this in turn can cause mental health issues, problems with work and socialising and lead to physical ill health and increased inflammation.

The calming aspect of progesterone is key here. Where oestrogen and testosterone are stimulating hormones and give us ‘get up and go’. Progesterone calms us down and is catalytic in stimulating our parasympathetic nervous system and this side of our nervous system is responsible for sleep, enabling us to digest our food and stimulating our libido. If we don’t have the mechanism to switch into our parasympathetic nervous system, we end up wired and tired, constantly in a state of agitation and nervousness or defence. We will have digestive issues, sleep issues and a compromised immune system.

Progesterone is an anti-inflammatory, there have been incredible results using this brilliant hormone with auto immune disease.

Progesterone is the precursor hormone to cortisol one of our stress hormones. If cortisol is elevated due to stress, poor diet, lack of sleep and emotional issues, progesterone will be reduced, and this can cause huge fall out because it means that the ratio of progesterone to oestrogen becomes imbalanced and we have too much oestrogen. This is called ‘oestrogen dominance’ and this is behind a lot of women’s health issues such as headaches, weight gain, some types of PCOS and at extreme levels, some cancers.

This ratio of one hormone to the other is what is important because whilst all our hormones are useful, too much of one means that it’s opposite will become ‘unopposed’ and this unopposed hormone can cause major issues. For example, unopposed testosterone can cause hair loss, acne, PCOS and aggression.

Where the issue with low progesterone becomes challenging is that the medical model often give out synthetic progesterone in the form of the contraceptive pill, some HRT, implants and the hormonal IUD coil as a way to manage conditions and symptoms.

But, as we have talked about before, synthetic progesterone (which is also called progestin) is not progesterone.

Chemically these progestins are called drospirenone, levonorgestrel, or medroxyprogesterone and as you can see in the diagrams below, they look different to progesterone.

The image attached shows the chemical difference between levonorgestrel, which is the progestin used many oral contraceptives, implants, hormonal IUD coil, and the morning-after pill, and natural progesterone.

Chemically these are totally different. Levonorgestrel is more similar to testosterone than it is to progesterone (which is problematic because as we know progesterone is a calming hormone whereas testosterone is an exciter hormone.

This is important because of how they affect the body.


  • beneficial for cardiovascular health
  • stimulates hair growth.
  • calms mood and promotes sleep.
  • prevents breast cancer.
  • Anti inflammatory.


  • increases the risk of fatal blood clots
  • can cause hair loss (due to its similarity to testosterone)
  • may cause anxiety and depression
  • increases the risk of breast cancer

Women need progesterone to support adrenal function and remember when we are too stressed, we turn progesterone into cortisol. We need that calming action a lot more than we need more “upregulating” hormones.

What’s terrifying is that there is evidence to show that women who have been using synthetic progesterone can’t make enough of their own progesterone and their blood test results often show ‘post-menopausal’ levels of progesterone. But we can be talking about young women here. Even more terrifying is that a lot of these women never manage to make their own hormones again when they come off of the synthetics and end up infertile.

In peri menopause the first hormone to destabilise is progesterone but the medical model overlooks this and give out HRT that contains both when oestrogen is still often at an optimal level for some time.  In our experience, women who work with specialists who understand that for a short period of time, until oestrogen destabilises, progesterone can be a game changer. “The adrenal cortex is almost the exclusive source of plasma oestrogen, progesterone and DHEA in post-menopausal women”

There has been a trend in the medical model of overlooking progesterone and focussing on oestrogen. High dose oestrogen therapy is now commonly used without women having a real progesterone to oppose it, and when women complain they feel unwell they get put on higher and higher doses of oestrogen not progesterone which leads to even more symptoms than they had before. This practice is damaging women, and celebrity doctors who have advertised this method are now coming under scrutiny with one being investigated by the GMC. The science just doesn’t stack up and women are suffering.

Even more frustrating is that women with conditions like PCOS and endometriosis are offered synthetic progestins as a standard method of treatment, but they are never offered natural progesterone.

Some GP surgeries are even financially remunerated for giving women synthetic progesterone in the form of the hormonal IUD coil which means that women often feel bullied into having this device when the go for their appointments.

It’s a big problem and one we will only counter with assertiveness and making requests of our healthcare providers, but we can only do that with education. Progesterone is an incredibly important hormone. Its time it stopped being overlooked and given credit for how much it does to keep up healthy and emotionally stable.