Progesterone deficiency: Signs, symptoms and root causes

Progesterone is one of the two main female sex hormones, yet it’s often the one we hear least about. Although everyone produces progesterone, women produce much higher levels during their reproductive years after puberty, while men and children produce much smaller amounts. Progesterone is often referred to as the primary female reproductive hormone because it plays a central role in the menstrual cycle and pregnancy.

The hormone fluctuates throughout a woman’s cycle, and when levels dip too low, they can affect sleep and fertility. Often, a progesterone deficiency can go undiagnosed for years as symptoms can align with other common ailments.

In this guide, our women's health expert, practitioner Josephine Smith (BSc Health Science) explains what progesterone deficiency actually means, how to spot the signs of low progesterone, what causes it (including why it can start in your 30s), as well as the medical and holistic options for treating it.

Key Takeaways:

• Progesterone is produced mainly after ovulation, so if you don’t ovulate regularly, your levels fall -  which is why low progesterone becomes more common with age, stress and perimenopause

• Common signs of low progesterone include irregular or short periods, worsening premenstrual symptoms (PMS), low mood, anxiety, interrupted sleep and fertility problems

• Progesterone deficiency/lower progesterone is treatable - depending on the cause, lifestyle changes and, where appropriate, hormone replacement therapy can all help (following GP advice)

What does low progesterone mean?

Low progesterone means your body isn’t producing enough of the progesterone hormone when it’s needed (during your cycle, after ovulation), which can affect everything from your menstrual cycle to fertility and mood.

Progesterone is a hormone produced after ovulation that helps prepare the womb for pregnancy; it counteracts the effects of oestrogen and supports mood, sleep and body temperature. This only changes during pregnancy when the placenta takes over progesterone production. 

When you’re deficient in progesterone, it means your body isn’t making enough of the hormone for these processes to run smoothly (this tends to be because ovulation isn’t happening consistently).

Low progesterone doesn’t always mean you have low oestrogen too. In many cases, oestrogen levels stay the same while progesterone falls, creating a hormone imbalance that’s sometimes called “oestrogen dominance”. That’s why your symptoms depend on the balance between the two hormones.

How many women have low progesterone?

Low progesterone levels are quite common and can affect women at any stage of reproductive life. However, it becomes more common from the mid-30s onwards, and falling progesterone is a normal part of the transition to menopause. In the UK, an estimated 13 million women in the UK are currently perimenopausal or menopausal - a stage in which falling progesterone is one of the key hormonal changes.

What causes low progesterone?

The main cause of low progesterone is irregular ovulation or not ovulating at all. As progesterone is made by the corpus luteum (a temporary, hormone-secreting mass of cells that forms in the ovary after an egg is released during ovulation), any cycle where ovulation doesn’t happen means there is little to no progesterone produced.

Common reasons why include:

• Perimenopause and ageing - As you approach menopause, ovulation becomes less frequent, so progesterone is usually the first hormone to decrease.

• Chronic stress - High cortisol can interfere with ovulation and affect how your body produces progesterone

• Polycystic ovary syndrome (PCOS) - An irregular or a lack of ovulation can lead to consistently low levels of progesterone

• Being underweight, exercising too much, or not eating enough - can affect the hormones that trigger ovulation, making it harder for your body to release an egg

• Thyroid problems and high prolactin - can both disrupt the signals that trigger ovulation.

• Luteal phase defect - Even if you ovulate, your body may not produce enough progesterone, or the hormone may drop too quickly.

What can cause low progesterone in your 30s?

The signs of low progesterone can start as early as your 30s. Perimenopause can begin up to 10 years before your final period, and ongoing stress, poor sleep, and not eating well can affect ovulation, causing progesterone levels to fall before you notice more typical menopausal symptoms.

Low Progesterone Symptoms

Progesterone impacts so many systems within the body, which means progesterone deficiency symptoms can appear as numerous ailments, and they tend to worsen over time. The most common signs of low progesterone include:

• Irregular or missed periods

• Worsening PMS (premenstrual syndrome)

• Difficulty falling or staying pregnant

• Mood changes, anxiety, or depression

• Hot flushes or night sweats

• Insomnia/interrupted sleep

• Regular headaches

Less common but still a key indicator is changes to your period - including shorter cycles, spotting or heavier or more painful bleeding, breast tenderness or migraines that flare up around your period. Because progesterone balances oestrogen, low levels can tip you towards oestrogen-dominant symptoms such as bloating, fluid retention and mood swings too.

How do I know if I have low progesterone?

The only way to know for certain is a blood test, usually taken around day 21 of a 28-day cycle (about seven days after ovulation), when progesterone should be at its peak. Your GP can arrange this and may also check oestrogen, thyroid and prolactin to build a fuller picture. If your cycles are irregular, the timing of the test may need adjusting. Using a period tracker app can help you get a better visualisation of your cycle. 

What does low progesterone feel like?

For many women, low progesterone feels like an extended period of PMS with low moods, poor sleep, tender breasts and frequent headaches.

Can low progesterone cause anxiety?

Low progesterone can show as anxiety in many people, studies show. When your body breaks down progesterone, it produces a natural chemical (called allopregnanolone) that can help you feel calm and relaxed. If your progesterone levels are low, or they drop before your period, you can lose some of that calming effect. This can leave you feeling more anxious or low, which is why these symptoms are so common with PMS and during perimenopause.

Does low progesterone cause weight gain?

There’s currently no direct link between low progesterone and weight gain. However, hormonal shifts relating to higher levels of oestrogen can cause bloating and fluid retention that can feel like weight gain for some. In perimenopause, when progesterone falls, changes in metabolism, sleep and activity levels can all contribute to genuine weight changes, but these are driven by wider hormonal changes rather than just progesterone alone.

Low Progesterone in Perimenopause/Menopause

Perimenopause is the transition before your periods stop for good (the menopause). It usually shows as changing periods and erratic cycles. This typically starts when a woman is in her mid-to-late 40s; in some, it can appear as early as your late 30s, although this is less common. 

Low progesterone can often be a sign of perimenopause. In the early stages, ovulation becomes less regular and because progesterone depends on ovulation, it’s usually the first hormone to decline, even while oestrogen is still fluctuating at normal or even high levels. 

As you move into menopause itself (defined as 12 months after your last period), both oestrogen and progesterone settle at low levels. By this point, progesterone deficiency symptoms in menopause tend to merge with the broader menopausal symptoms - HRT is usually the more considered option in this case.

How does low progesterone affect fertility?

Progesterone is a key hormone for fertility and pregnancy, which is why it’s often measured when investigating infertility. Produced after ovulation, it prepares and maintains the womb lining so a fertilised egg can implant and grow. If progesterone levels are too low, it can make the womb lining less receptive and harder to conceive or support an early pregnancy. Towards the latter end of the first trimester, at around 8 - 10 weeks, the placenta takes over progesterone production.

Can low progesterone cause miscarriage?

Low progesterone has been associated with early miscarriage, but this is just one factor among many. In many cases, low progesterone may be a sign that a pregnancy isn’t developing as expected, rather than the direct cause. However, research has shown that progesterone treatment can help some women with early pregnancy bleeding who have previously experienced one or more miscarriages.

How do you fix low progesterone?

There’s no one-size-fits-all solution when trying to regulate hormone levels, as the treatment has to be tailored to you, your symptoms and your reasons for wanting to ‘fix’ it. Before focusing on raising progesterone, it’s worth confirming whether you’re ovulating regularly. Low progesterone is often linked to irregular or absent ovulation, so identifying and treating the underlying cause is usually the most effective long-term approach.

The first step, like with all medical issues, is to speak to your GP, ask for a proper assessment and arrange a plan. 

• Address a potential underlying cause: 

If low progesterone is driven by stress, under-eating, over-exercising, thyroid problems or PCOS, treating that underlying issue is the most effective long-term fix. Looking at solutions to manage regular ovulation can help restore progesterone.

• Support low progesterone symptoms holistically:

Taking a deeper look at your lifestyle and potential triggers can help manage lower progesterone levels naturally. Reducing your exposure to things that make you feel stressed, prioritising a healthy sleep schedule, eating enough and eating a nutrient-rich diet (including healthy fats and protein) and keeping exercise balanced rather than extreme can all help support a healthy and regular cycle.

• Request medical treatment:

Where appropriate, doctors can prescribe body-identical progesterone. In perimenopause and menopause, this is often given as part of HRT, where progesterone is included to protect the womb lining alongside oestrogen. If you’re trying to conceive or are in early pregnancy with risk factors, progesterone pessaries may be offered. Note that these are all prescribed treatments and need to be tailored to you.

Vitamins and Supplements for Low Progesterone

While supplements can’t replace progesterone or treat a deficiency on their own, certain nutrients play a supporting role in healthy hormone balance and a regular cycle. Vitamin B6 is involved in hormone regulation and is traditionally used to ease PMS; magnesium and zinc can support the nervous system, sleep and ovulation; and vitamin D supports overall hormonal health. 

In particular, Chaste Tree Berry,  a women's health supplement by Vitanica, is a herbal supplement traditionally used to support women’s hormonal health. Some evidence suggests it may help relieve symptoms of PMS and support regular ovulation, which may in turn help maintain healthy progesterone levels in women who are ovulating. Some women also use it during perimenopause and menopause.