By Leila Martyn, Founder of MyOva

Low progesterone almost always means one thing: you didn't ovulate that cycle, or ovulation was weak. Progesterone is made by the corpus luteum, the structure left behind after an egg is released, so no ovulation means little progesterone. The most reliable signs are irregular or missing periods, a short second half of your cycle and trouble getting pregnant. Many of the "symptoms" you'll see online, like anxiety, poor sleep, headaches and sore breasts before your period, are common in women whose progesterone is completely normal.

You're not imagining your symptoms. But if you want answers, it helps to know which signs point to progesterone and which ones usually don't. That's what this guide is for.

New to MyOva? Join our mailing list for evidence-led hormone guides in your inbox. If you want the bigger picture first, read our guide to the luteal phase, or our guide to anovulation if your periods are irregular.

In this guide

• What does progesterone actually do?
• What causes low progesterone?
• What are the 9 signs people link to low progesterone?
• Is it low progesterone or PMS?
• How is low progesterone tested?
• Can you raise progesterone naturally?
• Does low progesterone affect fertility?
• What happens to progesterone in perimenopause?
• When should you see a GP?
• FAQ

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What does progesterone actually do?

Your cycle runs in two halves. In the first half, oestrogen rises as an egg matures. After ovulation, the empty follicle turns into the corpus luteum, a temporary gland that makes progesterone for the rest of the cycle. That second half is your luteal phase, and it averages about 12 days [1].

Progesterone has three main jobs:

• It prepares the womb lining so a fertilised egg could implant. If there's no pregnancy, the corpus luteum breaks down, progesterone falls and your period starts.
• It raises your body temperature slightly. In one lab study, the whole 24-hour temperature curve sat about 0.4°C higher in the luteal phase [2]. That's why temperature tracking can confirm ovulation after the fact.
• It acts on the brain. The body turns some progesterone into allopregnanolone, a neurosteroid that acts on the same calming GABA-A receptors as some anti-anxiety medicines [3].

Here's the bit that rarely gets taught: progesterone isn't a hormone that drifts "a bit low" on its own. Its level depends almost entirely on whether you ovulated that month and how well. Root cause, not symptom suppression: if progesterone is low, the real question is why ovulation isn't happening.

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What causes low progesterone?

The NHS lists the common reasons periods become irregular or stop [4]. Most of them work by switching off ovulation, which means switching off your main source of progesterone:

• PMOS (PCOS). Polyendocrine metabolic ovarian syndrome, formerly polycystic ovary syndrome, is the most common cause of irregular ovulation. In months without ovulation, there's no luteal phase and no progesterone rise.
• Perimenopause. As you approach menopause, more cycles are anovulatory, and progesterone from the corpus luteum can be normal or reduced [5].
• Stress, sudden weight loss and too much exercise. All three are on the NHS list [4]. They can turn down the brain signals that trigger ovulation.
• Thyroid problems. Both an overactive and an underactive thyroid can disturb periods. Hypothyroidism is mainly linked to infrequent periods [6].
• Breastfeeding and hormonal contraception also stop periods or ovulation [4]. With the pill, implant or injection, that's the point: the synthetic hormone does the job your own progesterone would.

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What are the 9 signs people link to low progesterone?

Most lists of "low progesterone symptoms" treat every sign as equal. They aren't. Here's how good a clue each one is.

1. Irregular or missing periods

This is the strongest clue. If you're not ovulating, there's no corpus luteum and no progesterone rise, and periods often become unpredictable or stop. The NHS advises seeing a GP if you've missed three periods in a row or your periods have become irregular [4].

2. A short luteal phase

A luteal phase of 10 days or less is the usual definition of short. The American Society for Reproductive Medicine says it's linked to too little progesterone, or progesterone that doesn't last long enough. It also says a short luteal phase happens in fertile women and hasn't been proven to cause infertility on its own [7]. Large app data shows about 18% of cycles have a luteal phase under 11 days [1].

3. Trouble getting pregnant

Ovulation problems are one of the main reasons for difficulty conceiving, and a progesterone blood test is one of the first checks [8]. But plenty of other things affect fertility, for both partners. Difficulty conceiving isn't proof of low progesterone.

4. Bleeding in early pregnancy after a previous miscarriage

This is where progesterone treatment has the clearest evidence. NICE recommends offering vaginal micronised progesterone 400 mg twice a day to women with bleeding in early pregnancy who have had a miscarriage before, once a scan confirms the pregnancy is in the womb [9]. This is a prescribed medicine, managed by your doctor or early pregnancy unit. It isn't something to try with over-the-counter products.

5. Heavy or erratic periods in perimenopause

In perimenopause, oestrogen can swing high while progesterone from the corpus luteum may be normal or lower. Researchers have suggested this combination may contribute to irregular bleeding [5]. Heavy or erratic bleeding has other causes too, so it always deserves a GP visit.

6. Spotting before your period

Spotting in the days before a period is often blamed on low progesterone online, but we couldn't find good evidence that it reliably signals it. The NHS lists other causes of bleeding between periods, including hormonal contraception, polyps, fibroids and infections such as chlamydia, and advises getting it checked [10].

7. Anxiety or low mood before your period

Premenstrual mood changes are real, and they matter. But in a landmark 1998 trial, women with PMS whose own hormones were switched off felt better, and their symptoms came back when normal levels of oestrogen or progesterone were added back. Women without PMS got the same hormones and had no symptoms [11]. The problem was sensitivity to normal hormone changes, not low levels.

8. Poor sleep before your period

Self-reported sleep gets worse in some, but not all, women when premenstrual symptoms start [12]. That happens whether or not progesterone is low, so poor sleep alone tells you little about your levels. Our guide on why you can't sleep before your period goes deeper.

9. Headaches before your period

The Migraine Trust explains that the natural fall in oestrogen before a period can make a migraine attack more likely [13]. It doesn't link period migraine to progesterone. See our guide to hormonal headaches for what helps.

What about breast tenderness and low libido? You'll see both on many lists. Breast tenderness is a common premenstrual symptom [14], and it happens in the luteal phase when progesterone is normally at its highest, so it's not a sign of low levels. We couldn't find good evidence linking low libido specifically to low progesterone either.

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Is it low progesterone or PMS?

This is the mix-up we see most. PMS and PMDD (premenstrual dysphoric disorder) cause mood, sleep and physical symptoms in the second half of a regular cycle. That means you're ovulating, which means you're making progesterone. Research points to a different sensitivity to normal hormone changes, possibly involving allopregnanolone, rather than low levels [3, 11].

About 4 in 10 women have premenstrual symptoms, and 5 to 8% of those have severe PMS [15]. The NHS suggests keeping a symptom diary for at least 2 cycles and taking it to your GP [14]. If your symptoms cluster before your period and lift within a few days of it starting, read PMDD vs Severe PMS.

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How is low progesterone tested?

The NHS uses a progesterone blood test to check whether you're ovulating, timed according to how regular your periods are [8]. The key rule is to time it from your period, not the calendar:

• Take it about 7 days before your next expected period. For a 28-day cycle that's day 21. For a 35-day cycle it's around day 28 [16].
• About 30 nmol/L or more is good evidence that you ovulated. A lower result doesn't rule ovulation out, because the test may simply have been taken on the wrong day [16].
• If your cycles are irregular, a single test is hard to time. The NHS says women with irregular periods may be offered other hormone tests instead [8].

If you've been told your progesterone was "normal" or "low" without anyone asking about your cycle length, it's reasonable to go back and ask whether the timing was right. That's not being difficult. That's hormonal literacy.

For the wider set of tests worth asking about with irregular cycles, see what blood tests to ask for.

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Can you raise progesterone naturally?

This is what I wish someone had told me: you can't eat your way to more progesterone. Your body makes it after ovulation, so anything that "supports progesterone" has to work by supporting ovulation. In practice that means:

1. Find the cause. PMOS, thyroid problems, low body weight and perimenopause all need different approaches. That's a GP conversation, not a guessing game.
2. Eat enough. Sudden weight loss and too much exercise are on the NHS list of reasons periods stop [4].
3. Look after your stress load. Stress is on the same NHS list [4]. Sleep, movement you enjoy and talking therapies all count.
4. Be wary of progesterone creams. The British Menopause Society says progesterone absorbed through the skin is unreliable and doesn't recommend compounded "bioidentical" products, because there's no evidence their dose is enough [17]. That advice is about protecting the womb lining during HRT, but it shows how poorly these creams are absorbed.

On nutrients, here's what UK law lets us say. Vitamin B6 contributes to the regulation of hormonal activity, and to normal psychological function and the reduction of tiredness and fatigue [18]. That's a general role for a nutrient. It isn't a promise that B6 raises progesterone, and no supplement is a treatment for low progesterone. Keep total vitamin B6 from supplements to 10 mg a day or less unless a doctor advises otherwise [19].

It's not a magic fix. But it gives your body what it's often missing.

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Does low progesterone affect fertility?

If you're not ovulating, you can't conceive that cycle, and that's the main way low progesterone affects fertility. Whether a short or weak luteal phase in an otherwise ovulatory cycle reduces fertility is less clear. ASRM says it hasn't been proven to be an independent cause of infertility or recurrent miscarriage, and that it's unclear whether treating it improves outcomes [7].

What UK guidance says to do:

• See a GP if you haven't conceived after a year of trying. Go sooner if you're 36 or over, or already know you may have fertility problems [20]. You might see "6 months if over 35" online, but that's US advice.
• Take folic acid, 400 micrograms a day, from before you're pregnant until 12 weeks [21].
• If you bleed in early pregnancy and have miscarried before, ask about progesterone, which NICE recommends in that situation [9].

You'll often see myo-inositol recommended for ovulation. NICE's draft PMOS (PCOS) guideline says inositol is not effective for fertility problems [22]. We'd rather you hear that from us than find out later.

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What happens to progesterone in perimenopause?

Perimenopause doesn't start with hot flushes for most women. It often starts with cycles changing. As you approach menopause, a growing share of cycles are anovulatory. Progesterone in the cycles that do ovulate may be normal or lower, while oestrogen can swing high and low like a rollercoaster [5]. That mix may help explain the irregular, sometimes heavier bleeding many women notice.

If you start HRT and still have a womb, you'll need a progestogen alongside oestrogen to protect the womb lining. The British Menopause Society lists micronised progesterone taken by mouth as one option, and says creams don't protect the lining adequately [17]. Your GP or menopause specialist will tailor the dose. Our perimenopause guide covers the rest.

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When should you see a GP?

Book a GP appointment if:

• You've missed three periods in a row, or your periods have become irregular [4].
• You've missed a period and also notice weight changes, tiredness, extra facial hair, or dry or oily skin [4].
• You're bleeding between periods or after sex [10].
• You haven't conceived after a year of trying, or sooner if you're 36 or over [20].
• Premenstrual symptoms are affecting your work, relationships or daily life [14].

Get urgent help (urgent GP appointment or NHS 111) if you've missed a period and have unusual bleeding with tummy or pelvic pain, as this can be a sign of ectopic pregnancy [10].

Your diagnosis is a starting point, not a verdict. If you've felt brushed off before, our guide to advocating for yourself at the GP can help.

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Frequently asked questions

Can low progesterone cause anxiety?
Progesterone is turned into allopregnanolone, which acts on calming GABA-A receptors in the brain [3]. But premenstrual anxiety usually happens in women with normal progesterone, and research points to sensitivity to normal hormone changes rather than low levels [11]. Anxiety on its own isn't a reliable sign of low progesterone.

Can you get pregnant with low progesterone?
If low progesterone means you didn't ovulate, you can't conceive that cycle. If you ovulate but have a shorter luteal phase, pregnancy is still possible. ASRM says a short luteal phase hasn't been proven to cause infertility on its own [7]. See a GP after a year of trying, or sooner if you're 36 or over [20].

Does day 21 progesterone work if my cycle isn't 28 days?
No. The test should be taken about 7 days before your next expected period, which is only day 21 in a 28-day cycle [16]. If your cycles are irregular, ask your GP how to time it, or whether other tests make more sense [8].

Do progesterone creams work?
The British Menopause Society says progesterone absorbed through the skin is unreliable, and it doesn't recommend compounded "bioidentical" products [17]. If you need progesterone for a medical reason, it should be prescribed.

Is low progesterone the same as oestrogen dominance?
Not quite. "Oestrogen dominance" isn't a recognised diagnosis, but cycles without ovulation do leave oestrogen unopposed by progesterone. Our article on oestrogen dominance explains the difference.

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The bottom line

Low progesterone is mostly a story about ovulation. Irregular or missing periods, a consistently short luteal phase and trouble conceiving are the signs worth acting on. Mood, sleep and headache changes before your period are real and worth treating, but they rarely mean your progesterone is low. Your body is trying to tell you something: track your cycle, get the progesterone test timed properly, and ask your GP why ovulation isn't happening if the answer is that it isn't.

Related Reading

• Luteal Phase: 7 Signs, Symptoms and What Actually Helps
• Anovulation: What It Is, Why It Happens and What Helps
• PMDD vs Severe PMS: How to Tell the Difference
• Oestrogen Dominance: Is It Real? What the Research Says
• Perimenopause: The Complete Guide
• How to Support Your Cycle After Coming Off the Pill

This article is for general information only and isn't medical advice. MyOva products are food supplements, not medicines, and aren't intended to diagnose, treat, cure or prevent any disease. Speak to your GP or pharmacist before taking supplements if you're pregnant, breastfeeding, taking medication or managing a diagnosed condition.

References

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2. Baker FC, Waner JI, Vieira EF, Taylor SR, Driver HS, Mitchell D. Sleep and 24 hour body temperatures: a comparison in young men, naturally cycling women and women taking hormonal contraceptives. Journal of Physiology. 2001;530(3):565-574.
3. Hantsoo L, Epperson CN. Allopregnanolone in premenstrual dysphoric disorder (PMDD): evidence for dysregulated sensitivity to GABA-A receptor modulating neuroactive steroids across the menstrual cycle. Neurobiology of Stress. 2020;12:100213.
4. NHS. Missed or late periods. Reviewed 12 June 2026.
5. Kuokkanen S, Santoro N. Endocrinology of the perimenopausal woman. Global Library of Women's Medicine. 2011. doi:10.3843/GLOWM.10082.
6. Krassas GE, Poppe K, Glinoer D. Thyroid function and human reproductive health. Endocrine Reviews. 2010;31(5):702-755.
7. Practice Committees of the American Society for Reproductive Medicine and the Society for Reproductive Endocrinology and Infertility. Diagnosis and treatment of luteal phase deficiency: a committee opinion. Fertility and Sterility. 2021;115(6):1416-1423.
8. NHS. Infertility: diagnosis. Reviewed 9 August 2023.
9. NICE. Ectopic pregnancy and miscarriage: diagnosis and initial management (NG126). Recommendations 1.9.2 to 1.9.3.
10. NHS. Vaginal bleeding between periods or after sex. Reviewed 13 August 2024.
11. Schmidt PJ, Nieman LK, Danaceau MA, Adams LF, Rubinow DR. Differential behavioral effects of gonadal steroids in women with and in those without premenstrual syndrome. New England Journal of Medicine. 1998;338(4):209-216.
12. Baker FC, Lee KA. Menstrual cycle effects on sleep. Sleep Medicine Clinics. 2022;17(2):283-294.
13. The Migraine Trust. Migraine and hormones.
14. NHS. PMS (premenstrual syndrome). Reviewed 18 June 2024.
15. Royal College of Obstetricians and Gynaecologists. Management of Premenstrual Syndrome: Green-top Guideline No. 48. BJOG. 2017.
16. Gloucestershire Hospitals NHS Foundation Trust Pathology. Progesterone.
17. British Menopause Society. Progestogens and endometrial protection: Tool for Clinicians. Reviewed February 2026.
18. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register.
19. Food Standards Scotland. Vitamin B6 (pyridoxine).
20. NHS. Infertility. Reviewed 9 August 2023.
21. NHS. Vitamins, supplements and nutrition in pregnancy. Reviewed 1 September 2023.
22. NICE. Polyendocrine metabolic ovarian syndrome (PMOS): draft guideline for consultation (GID-NG10436). July 2026. Recommendation 1.21.18.

References