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Hormones

What Is Progesterone? Role in Cycle, Pregnancy & Symptoms

Clara Siegmund
Clara Siegmund

Hormones, including progesterone, are crucial to your health. In this guide to progesterone, we’ll answer all your progesterone-related questions, including what is progesterone and what does it do.

Modified On:
October 16, 2025
Published:
Apr 25, 2025
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Diagram showing progesterone levels throughout menstrual cycle phases
Published:
Oct 17, 2025
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Hormones, including progesterone, are crucial to your health. In this guide to progesterone, we’ll answer all your progesterone-related questions, including what is progesterone and what does it do.

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Hormones, including progesterone, are crucial to your health. In this guide to progesterone, we’ll answer all your progesterone-related questions, including what is progesterone and what does it do.

Hormones are powerful actors in your body, playing roles in everything from physical functions, to emotional regulation, to overall health.

Progesterone, a key reproductive hormone, is crucial for regulating your menstrual cycle, conceiving, and supporting a pregnancy.

So, what is progesterone? Read on to learn what this hormone is, what it does in your body, how progesterone fluctuates throughout your cycle and across different life stages, symptoms of low versus high progesterone, and how to track progesterone.

What is progesterone?

Progesterone is one of your central reproductive hormones. 

Alongside other reproductive hormones like estrogen, luteinizing hormone (LH), and follicle-stimulating hormone (FSH)—progesterone is an essential element to reproductive health and the menstrual cycle, across life stages.

Progesterone is produced by the:

  • Ovaries: the glands where eggs are produced, located on either side of your uterus at the ends of the fallopian tubes
  • Corpus luteum: a temporary gland formed after ovulation 
  • Adrenal glands: hormone-producing glands above the kidneys

Want to understand the full cycle picture? Read: Progesterone: The Key Hormone in Your Cycle→

What does progesterone do?

Progesterone plays key roles in reproductive health, particularly in the menstrual cycle and pregnancy.

From cycle to cycle, progesterone helps regulate:

If you become pregnant in a given cycle, progesterone is essential for:

  • Embryo implantation in the endometrium
  • Embryo development
  • Supporting the pregnancy
  • Preventing miscarriage 
  • Preparing the body for breastfeeding (or chestfeeding)

Progesterone isn’t just involved in reproductive health, though. This hormone also helps control functions throughout your body, including:

  • Mood
  • Thyroid function
  • Energy levels
  • Fatigue levels
  • Bone health
  • Heart health

Progesterone and the menstrual cycle

Progesterone helps control how regular your periods are, plus how heavy or how light your flow is. 

Levels of this hormone naturally fluctuate throughout your cycle, rising or falling depending on cycle phase. Here’s how.

Progesterone during the follicular phase

Your cycle starts with the follicular phase, on day 1 of your period. 

During this phase, you have your period and your body prepares for ovulation. Progesterone levels are low in the follicular phase.

Progesterone during the ovulatory phase

Around mid-cycle, ovulation occurs and your ovaries release a mature egg. If this egg gets fertilized, you can become pregnant.

The follicle that housed the egg prior to ovulation then becomes a corpus luteum. This temporary structure starts producing progesterone, making progesterone levels begin to rise.

The increase in progesterone signals the end of the ovulatory phase. It also confirms ovulation if progesterone doesn’t rise, it means you didn’t ovulate.

Progesterone during the luteal phase

Right after ovulation, you enter the second half of your cycle: the luteal phase.

During the luteal phase, progesterone levels are high. Rising progesterone makes the endometrium grow thick and full of nutrients, preparing the uterus for a potential pregnancy.

While progesterone naturally rises during the luteal phase and pregnancy, abnormally high levels can cause uncomfortable symptoms. Learn more about high progesterone symptoms: High Progesterone Symptoms: What They Mean→

Progesterone at the end of the menstrual cycle

What progesterone does at the end of a cycle, in the very late luteal phase, depends on whether or not you became pregnant in that cycle. 

If you’re not pregnant, progesterone levels drop back down. Then, you get your next period and the next cycle starts. 

If you are pregnant, progesterone stays elevated.

Progesterone during pregnancy

From conception to delivery, progesterone plays a major role in pregnancy. In fact, it’s sometimes called the pregnancy hormone.

For starters, progesterone is crucial for getting pregnant. Without progesterone, the endometrium doesn’t thicken properly. Without a thickened endometrium, the uterus isn’t prepared for a pregnancy, and a fertilized egg can’t implant and become an embryo.

Progesterone is also essential for supporting and maintaining a pregnancy. When you’re pregnant, progesterone continues to nourish the endometrium, which in turn supports the growing fetus. Progesterone also helps keep the uterus from contracting, which is part of what prevents miscarriages. 

During pregnancy, progesterone levels are high, increasing the further along you are.

Progesterone during perimenopause

Before reaching menopause, you first go through perimenopause, or the menopausal transition. Perimenopause can last several years, and may start anywhere from your mid-to-late 30s, to your early-to-mid (or even late) 40s—each person’s timeline is different. 

Perimenopause, a major, hormone-driven biological shift, triggers changes in your cycle, periods, and ovulation as you approach the end of your reproductive capabilities.

During perimenopause, progesterone fluctuates and declines overall. The decline isn’t steady, however. Instead, progesterone oscillates unpredictably from cycle to cycle (as do estrogen and LH), leading to uncomfortable, distressing, or even painful perimenopause symptoms.

Progesterone during menopause

You officially reach menopause once you’ve gone 12 consecutive months without a period.

At this point, progesterone stops fluctuating and stabilizes at its new baseline. This can bring symptom changes and even symptom relief. 

Post-menopause, progesterone is very low.

Low progesterone and high progesterone

Sometimes, progesterone may become low or high. But low or high compared to what? Well, your other hormones. 

Your hormones work together in a complex and intricate balance to make sure everything in your body functions properly. That balance naturally fluctuates as you move through your menstrual cycle, which can cause physical and emotional cycle symptoms.

If the balance is disrupted for a longer period of time, though, your hormones may be unable to do their job as intended. 

In this case, you may be dealing with a hormonal imbalance. A hormonal imbalance can trigger various symptoms, depending on which hormones are high and which are low. 

Low progesterone symptoms include:

Get the complete guide: Low Progesterone Symptoms: Signs and Solutions→

High progesterone symptoms include:

  • Irregular periods
  • Bloating
  • Weight gain
  • Breast tenderness
  • Acne
  • Fertility issues
  • Depressive symptoms 
  • More severe PMS symptoms
  • Fatigue

Consider talking with your doctor if you suspect you may be dealing with low progesterone or high progesterone. They can help you identify and manage any underlying issues.

How to track your progesterone levels

Measuring and tracking your progesterone levels enables you to follow cyclic changes and match symptoms with hormone fluctuations.

Multi-hormone test kits that measure progesterone, estrogen, and LH like the Oova fertility kit and app—are one great option for accurate, reliable, and easy at-home hormone tracking.

With Oova, you can monitor your cycle, track ovulation, decode your fertility, understand your perimenopause journey, plus use your hormone knowledge in your day-to-day life. This way, you can connect with your health and deepen your understanding of your body.

What is progesterone? The bottom line

Progesterone, a crucial reproductive hormone, is key to regulating the menstrual cycle, conceiving, and sustaining a pregnancy.

Progesterone levels naturally fluctuate in the span of a single cycle, and throughout your life from your reproductive years, to pregnancy, to perimenopause, to menopause.

Tracking your progesterone levels at home can help you take control of your health and fertility.

Frequently Asked Questions

What does progesterone do in simple terms?

Progesterone prepares your uterus for pregnancy after ovulation by thickening the uterine lining. If pregnancy occurs, it supports the developing fetus; if not, progesterone drops and you get your period.

When is progesterone highest in your cycle?

Progesterone is highest during the luteal phase (after ovulation), typically 7 days post-ovulation. Levels remain low during your period and before ovulation, then rise dramatically after an egg is released.

What are signs of low progesterone?

Signs of low progesterone include irregular or missed periods, heavy bleeding, spotting between periods, difficulty conceiving, recurrent miscarriages, anxiety, sleep disturbances, and hot flashes.

Does progesterone make you tired?

Yes, progesterone has a naturally calming effect and can cause fatigue, especially when levels are high during the luteal phase or pregnancy. This is why many women feel more tired in the second half of their cycle.

How does progesterone affect mood?

Progesterone produces allopregnanolone (ALLO), which has calming effects on the brain. However, when progesterone drops suddenly (like before your period), it can trigger anxiety, irritability, or depressive symptoms.

At what age does progesterone decline?

Progesterone begins declining during perimenopause, typically starting in your late 30s to mid-40s. After menopause (12 months without a period), progesterone stabilizes at very low levels.

About the author

Clara Siegmund
Clara Siegmund is a writer, editor, and translator (French to English) from Brooklyn, New York. She has a BA in English and French Studies from Wesleyan University and an MA in Translation from the Sorbonne. She is passionate about literature, reproductive justice, and using language to make information accessible.‍

Sources

  • Cable JK & Grider MH. (2023). Physiology, Progesterone.
  • NIH, National Institute on Aging. (2024). What Is Menopause?
  • Reed BG & Carr BR. (2018). The Normal Menstrual Cycle and the Control of Ovulation.
  • Cleveland Clinic. (2024). Progesterone. https://my.clevelandclinic.org/health/articles/22434-progesterone
  • Nagy, B., et al. (2021). Key to Life: Physiological Role and Clinical Implications of Progesterone. International Journal of Molecular Sciences, 22(20), 11039.
  • Prior, J. C. (2023). Progesterone for treatment of symptomatic menopausal women. Climacteric, 26(2), 128-133.
  • Santoro, N. (2024). Reproductive Hormones Across the Lifespan. The Journal of Clinical Endocrinology & Metabolism, 109(2).
https://www.oova.life/blog/progesterone-supplementation-guide
Can I take progesterone if I'm breastfeeding?
Yes, progesterone is generally safe while breastfeeding and doesn't significantly affect milk supply. However, always discuss with your healthcare provider before starting any hormone supplementation while nursing.
https://www.oova.life/blog/progesterone-supplementation-guide
Is it safe to take progesterone throughout pregnancy?
Yes, when prescribed by your healthcare provider. Progesterone supplementation in early pregnancy is safe and can reduce miscarriage risk in women with low progesterone or a history of pregnancy loss. Most providers continue supplementation through the first trimester (weeks 10-12) when the placenta takes over.
https://www.oova.life/blog/progesterone-supplementation-guide
Can progesterone supplementation cause weight gain?
Progesterone can cause temporary water retention and bloating, which may show up as a few pounds on the scale, but it doesn't cause true fat weight gain. Most women don't experience significant weight changes from progesterone supplementation.
https://www.oova.life/blog/progesterone-supplementation-guide
Can I switch from pills to suppositories or vice versa?
Yes, but only under your doctor's guidance. The dosing and timing may need adjustment when switching between forms since they're absorbed differently. Never switch on your own, especially if you're pregnant or undergoing fertility treatment.
https://www.oova.life/blog/progesterone-supplementation-guide
Will progesterone supplementation delay my period?
Yes, progesterone keeps the uterine lining intact, so if you're not pregnant and continue taking progesterone, your period will be delayed. Once you stop taking it, your period should start within 2-10 days. If you are pregnant, progesterone helps maintain the pregnancy and you won't get a period.
https://www.oova.life/blog/progesterone-supplementation-guide
Should I take progesterone pills orally or vaginally?
For fertility and pregnancy support, vaginal progesterone is usually preferred because it delivers higher concentrations directly to the uterus. For perimenopause or general hormone balance, oral progesterone often works well and is more convenient. Your doctor will recommend the best route based on your specific needs.
https://www.oova.life/blog/progesterone-supplementation-guide
When should I start taking progesterone after ovulation?
Typically, progesterone supplementation for luteal phase support starts 2-3 days after ovulation (confirmed by LH surge or temperature rise). Your doctor will give you specific timing based on your protocol. Some women start immediately after a positive ovulation test.
https://www.oova.life/blog/progesterone-supplementation-guide
What's better: progesterone cream or pills?
Pills (oral micronized progesterone) are generally more effective and reliable than creams because absorption from creams is inconsistent. For medical conditions like fertility issues, low progesterone, or HRT, prescription pills or suppositories are strongly recommended over over-the-counter creams.
https://www.oova.life/blog/low-vs-high-progesterone-symptoms
How can I tell if I have low or high progesterone?
The only definitive way to know is through hormone testing via blood tests or at-home urine tests that measure progesterone metabolites. However, symptom patterns can provide clues: anxiety and irregular periods suggest low progesterone, while bloating and extreme fatigue suggest high progesterone.
https://www.oova.life/blog/low-vs-high-progesterone-symptoms
When during my cycle should I test progesterone levels?
Test progesterone levels during the luteal phase, typically 7 days after ovulation or around day 21 of a 28-day cycle. This is when progesterone should be at its peak, making it easier to identify if levels are too low or too high.
https://www.oova.life/blog/low-vs-high-progesterone-symptoms
What are the main differences between low and high progesterone symptoms?
Low progesterone typically causes irregular or heavy periods, anxiety, hot flashes, and sleep issues. High progesterone causes bloating, fatigue, intense breast tenderness, and depression-like mood changes. Low progesterone symptoms persist throughout your cycle, while high progesterone symptoms are most intense during the luteal phase.
https://www.oova.life/blog/low-vs-high-progesterone-symptoms
Can you have symptoms of both low and high progesterone?
Some symptoms like breast tenderness and mood changes can occur with both low and high progesterone, making it confusing. However, the timing, intensity, and accompanying symptoms differ. Hormone testing is the best way to determine which imbalance you're experiencing.
https://www.oova.life/blog/10-dpo
Can stress affect 10 DPO symptoms?
Yes, stress can worsen or mimic 10 DPO symptoms. Stress increases cortisol, which can cause cramping, fatigue, and mood changes similar to both PMS and early pregnancy. During the two-week wait, try stress-reduction techniques like gentle exercise, meditation, or spending time with loved ones.
https://www.oova.life/blog/10-dpo
Is it better to test at 10 DPO or wait?
It's better to wait until 12–14 DPO for more accurate results. Testing at 10 DPO often leads to false negatives because hCG levels may still be too low. If you absolutely can't wait, use a sensitive early detection test with first morning urine, and be prepared to retest in 2–3 days if negative.
https://www.oova.life/blog/10-dpo
What does implantation bleeding look like at 10 DPO?
Implantation bleeding at 10 DPO is typically light pink or brown, much lighter than a period, and lasts 1–2 days. It's often just spotting when you wipe or a few drops on a panty liner. However, only 15–20% of pregnant women experience implantation bleeding—most don't have any bleeding at all.
https://www.oova.life/blog/10-dpo
Why am I cramping at 10 DPO?
Cramping at 10 DPO can be caused by elevated progesterone (whether you're pregnant or not), implantation (if you're pregnant), or premenstrual cramping. Unfortunately, cramping alone can't tell you if you're pregnant since progesterone causes similar symptoms in both scenarios.
https://www.oova.life/blog/10-dpo
What are the chances of a BFP at 10 DPO?
If you're pregnant, you have about a 50–60% chance of getting a positive test at 10 DPO. This means there's a 40–50% chance of a false negative even if you conceived. Chances improve significantly by 12–14 DPO.
https://www.oova.life/blog/10-dpo
What DPO is most accurate for pregnancy testing?
14 DPO (the day of your missed period) is the most accurate time to test, with 99% accuracy. 12 DPO offers 80–90% accuracy. 10 DPO has only 50–60% accuracy. For best results, wait as long as you can—ideally until 12–14 DPO.
https://www.oova.life/blog/10-dpo
Is 10 DPO too early to test?
10 DPO is considered early for pregnancy testing. While some women get positives at 10 DPO, accuracy is only 50–60% if you're pregnant. For best results, wait until 12 DPO (80–90% accuracy) or 14 DPO/missed period (99% accuracy).
https://www.oova.life/blog/10-dpo
Can you have implantation at 10 DPO?
Yes, implantation can still occur at 10 DPO, though 84% of women have already implanted by this point. Late implantation at 10–12 DPO is normal. If implantation happens at 10 DPO, you won't get a positive pregnancy test for another 2–3 days.
https://www.oova.life/blog/10-dpo
What does a negative test at 10 DPO mean?
A negative test at 10 DPO does not mean you're not pregnant. It's very common to get negatives at 10 DPO even if you conceived. Your hCG levels may still be too low, or implantation may have occurred later. Wait until 12–14 DPO to retest for more accurate results.
https://www.oova.life/blog/10-dpo
Can you get a positive pregnancy test at 10 DPO?
Yes, but only about 50–60% of pregnant women will get a positive at 10 DPO. The other 40–50% have hCG levels that are still too low to detect. If you test negative at 10 DPO, wait 2–3 days and test again.
https://www.oova.life/blog/high-progesterone-symptoms
Can high progesterone cause weight gain?
Yes, elevated progesterone can cause temporary weight gain through water retention and bloating. This is a normal part of the luteal phase and early pregnancy.
https://www.oova.life/blog/how-to-increase-estrogen
Does stress affect estrogen levels?
Yes, chronic stress elevates cortisol, which can suppress estrogen production and disrupt hormonal balance. Stress reduction through meditation, yoga, adequate sleep, and self-care practices helps maintain optimal estrogen levels.
https://www.oova.life/blog/how-to-increase-estrogen
When should I consider medical treatment for low estrogen?
Consider medical intervention if natural methods don't improve symptoms after 3 months, if symptoms severely impact quality of life, if you're experiencing early menopause (before 40), or if you have fertility concerns. Hormone replacement therapy may be appropriate in these cases.
https://www.oova.life/blog/how-to-increase-estrogen
What are the signs that my estrogen is increasing?
Signs of rising estrogen include more regular menstrual cycles, reduced hot flashes, improved vaginal lubrication, better mood stability, increased energy, and improved skin elasticity. You may also notice reduced symptoms that originally indicated low estrogen.
https://www.oova.life/blog/how-to-increase-estrogen
Can exercise increase estrogen levels?
Yes, moderate exercise stimulates estrogen release and helps maintain hormonal balance. Aim for 150 minutes of moderate cardio weekly plus strength training twice per week. However, excessive exercise can actually lower estrogen, so balance is key.
https://www.oova.life/blog/how-to-increase-estrogen
How long does it take to increase estrogen naturally?
With consistent dietary and lifestyle changes, you may notice improvements in symptoms within 4-8 weeks. However, significant hormonal changes typically take 2-3 months. Tracking your cycle and symptoms can help you monitor progress.
https://www.oova.life/blog/how-to-increase-estrogen
What foods increase estrogen levels naturally?
Foods high in phytoestrogens can help increase estrogen naturally. The best options include flax seeds (high in lignans), soy products (tofu, tempeh, edamame), lentils, chickpeas, whole grains (oats, quinoa, brown rice), and garlic. These plant compounds mimic estrogen's effects in the body.
https://www.oova.life/blog/perimenopause
What helps relieve hot flashes quickly?
Cool environments, layered clothing, herbal teas, and medical treatments like gabapentin or HRT may help—depending on severity. Lifestyle changes like reducing caffeine and alcohol can also provide relief.
https://www.oova.life/blog/perimenopause
Are there tests to confirm perimenopause?
Yes. Tests measuring estradiol, LH, and FSH levels can indicate hormonal shifts—but diagnosis is often symptom-based since hormone levels fluctuate widely during perimenopause.
https://www.oova.life/blog/perimenopause
How do I know it's perimenopause and not something else?
A doctor may recommend hormone testing (like LH, E3G, and PdG) and track symptom timing. Diagnosis is often based on symptoms combined with age and menstrual pattern changes.
https://www.oova.life/blog/perimenopause
What's the earliest age perimenopause can start?
Some women begin experiencing symptoms as early as their mid-30s, though perimenopause typically starts between ages 38-45.
https://www.oova.life/blog/perimenopause
Does perimenopause affect mental clarity?
Yes. Brain fog and difficulty concentrating are common during hormone fluctuations in perimenopause.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
What happens after the last sign of perimenopause?
After your final period, you enter postmenopause. You'll need 12 consecutive months without a period to confirm menopause. Many symptoms gradually improve, though some like vaginal dryness may persist without treatment.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
When do perimenopause symptoms finally stop?
Some symptoms like brain fog improve after menopause, while others like hot flashes may continue for up to 10 years post-menopause. Vaginal symptoms often persist or worsen without treatment. Each person's timeline is different.
https://www.oova.life/blog/high-progesterone-symptoms
Is high progesterone a sign of pregnancy?
Yes, high progesterone is one of the earliest indicators of pregnancy. Progesterone levels rise significantly after conception to support the developing embryo and reach their peak during the third trimester.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
Can you still get pregnant in late perimenopause?
Yes, you can still get pregnant during perimenopause as long as you're having periods, even if they're infrequent. Continue using birth control until you've gone 12 consecutive months without a period and have officially reached menopause.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
Do symptoms get worse before perimenopause ends?
Yes, most perimenopause symptoms intensify in the final 1-2 years before menopause. Hot flashes peak around your final period, vaginal symptoms worsen, and mood changes increase. However, brain fog typically improves in late perimenopause.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
How long does late perimenopause last?
Late perimenopause typically lasts 1-3 years before your final period. However, the exact duration varies significantly from person to person. You've reached menopause after 12 consecutive months without a period.
https://www.oova.life/blog/high-progesterone-symptoms
What are the symptoms of high progesterone?
High progesterone symptoms include fatigue, bloating, breast tenderness, weight gain, anxiety, depression, headaches, and food cravings. During pregnancy, you may also experience increased nipple sensitivity and muscle aches.
https://www.oova.life/blog/TBD-10-symptoms-and-how-to-get-relief
What are the first signs that perimenopause is ending?
The earliest signs include longer gaps between periods (60+ days), intensifying hot flashes that peak around your final period, and worsening vaginal dryness. These symptoms typically increase in late perimenopause before you reach official menopause.
https://www.oova.life/blog/high-progesterone-symptoms
When should I be concerned about high progesterone?
Consult a healthcare provider if you experience high progesterone symptoms outside your luteal phase when not pregnant, or if symptoms include severe pelvic pain, abnormal vaginal bleeding, or rapid weight gain while on hormone therapy.
https://www.oova.life/blog/high-progesterone-symptoms
How do you test progesterone levels?
Progesterone can be measured through blood tests at your doctor's office or at-home urine tests that measure PdG (a progesterone metabolite). Testing is typically done during the luteal phase, about 7 days after ovulation.

About the Oova Blog:
‍Our content is developed with a commitment to high editorial standards and reliability. We prioritize referencing reputable sources and sharing where our insights come from. The Oova Blog is intended for informational purposes only and is never a substitute for professional medical advice. Always consult a healthcare provider before making any health decisions.

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