- 01A low progesterone result usually means you did not ovulate
Progesterone is made by the corpus luteum after an egg is released. A low mid-luteal result almost always means that cycle had no ovulation or the test was drawn on the wrong day, so the next step is finding why ovulation stopped: PCOS, thyroid disease, high prolactin, under-fueling or perimenopause.
Low progesterone symptoms that track the hormone are cycle signs: a period that comes less than about 10 days after ovulation, spotting before a period, irregular or missed periods, and trouble conceiving. Progesterone only rises after an egg is released, so check when the blood was drawn before reading anything into symptoms. A low number is expected before ovulation, on most hormonal contraception and after menopause.
If your result was under 3 ng/mL, first check the draw day against the chart below. If it was not about 7 days before your period, ask your clinician to repeat it on the right day. If it was well timed and your cycles are irregular, ask them to add LH, FSH, prolactin and TSH to find out why ovulation stopped.
What progesterone does, in one minute
After ovulation, the empty follicle (the fluid sac the egg grew in) turns into the corpus luteum, a temporary gland on the ovary, which makes progesterone for about two weeks. Progesterone turns the uterine lining from a growing layer into one that can hold a pregnancy. If no pregnancy starts, the corpus luteum shrinks, progesterone falls, and the period follows. If a pregnancy does start, the corpus luteum keeps going until the placenta takes over at around weeks 8 to 10. The adrenal glands make a small amount in everyone, which is why men and postmenopausal women have low but measurable levels. Reference ranges, units and what moves the number are on the progesterone marker page.
The chart is why most low results are timing problems. Progesterone sits under 1 ng/mL for the whole first half of the cycle and peaks about 7 days after ovulation. A draw on day 21 lands near that peak only if you ovulated on day 14. With a 35-day cycle, ovulation is closer to day 21, and a day 21 draw catches progesterone before it has risen.
Symptoms of low progesterone in women, and how strong each link is
Most lists of low progesterone symptoms mix signs that follow directly from a missing or short luteal phase (the days between ovulation and your period) with complaints that have many causes. The table separates them. A strong link means the symptom follows from the biology and shows up reliably; a weak link means the symptom is common and progesterone is one possible contributor among many.
| Symptom | Why it happens | How strong the link is | What else causes it |
|---|---|---|---|
| Short luteal phase (period comes under about 10 days after ovulation) | The corpus luteum stops making progesterone early, so the lining sheds early | Strong | Perimenopause, under-eating, heavy training |
| Spotting in the days before a period | Progesterone falls unevenly and the lining starts breaking down early | Some | Endometrial polyps, fibroids, infection, cervical changes, contraception |
| Irregular, missed or absent periods | No ovulation means no progesterone rise and no clear signal to shed | Strong | PCOS, thyroid disease, high prolactin, low energy intake |
| Heavy or prolonged bleeding | Without progesterone, estrogen keeps thickening the lining until it sheds unevenly | Some | Fibroids, adenomyosis (lining tissue growing into the womb muscle), bleeding disorders, thyroid disease |
| Trouble getting pregnant | Without ovulation there is no egg to fertilize | Strong when cycles are irregular | Tubal, sperm and egg-quality factors |
| Early miscarriage | Low progesterone is usually a sign of a failing pregnancy, rarely the cause | Some, mostly as a marker | Chromosomal problems in the embryo (the most common cause) |
| PMS mood changes, anxiety, irritability | Brain sensitivity to normal hormone shifts | Weak for deficiency | Depression, anxiety disorders, thyroid disease, PMDD (a severe form of PMS) |
| Poor sleep before periods | Breakdown products of progesterone have a mild calming, sleep-promoting effect on the brain | Weak | Stress, caffeine, sleep apnea, perimenopause hot flashes |
| Breast tenderness, bloating | Hormone fluctuation across the cycle | Weak | Normal cycle changes, salt, caffeine |
| Weight gain | No consistent evidence progesterone level drives weight | Weak | Diet, activity, sleep, thyroid, insulin resistance |
Even for the cycle signs, there is no reliable test for a weak luteal phase. The American Society for Reproductive Medicine says no single progesterone level or biopsy separates fertile from infertile women, and treating it in natural cycles has not been shown to help 9. Heavy periods can also drain your iron; see iron deficiency and anemia.
Mood symptoms have the weakest link to low progesterone. In a 1998 NIH study, women with premenstrual syndrome had their ovarian hormones switched off, which cleared their symptoms; when progesterone or estradiol was added back, the symptoms returned, while women without PMS given the same hormones felt no change 4. PMS appears to track how the brain responds to a normal progesterone rise, and trials of progesterone treatment for PMS have not shown a clear benefit over placebo.
In women with a history of premenstrual syndrome, the occurrence of symptoms appears to represent an abnormal response to normal hormonal changes.
If sleep is the main complaint, stress, caffeine, sleep apnea and night sweats are more often to blame than progesterone; the can't sleep page works through them.
What counts as low? Progesterone levels by phase
Whether a progesterone result is low depends on the cycle phase. The only phase where a low number carries a clear message is the mid-luteal phase, about 7 days before your next period. The American Society for Reproductive Medicine treats a mid-luteal progesterone above about 3 ng/mL as good evidence that ovulation happened 1. Older studies used 10 ng/mL as the bar for an adequate luteal phase, but the ASRM's later review found no level that reliably separates adequate from inadequate 9.
Progesterone is released in bursts during the luteal phase, so two draws a few hours apart can differ widely. Treat a single result as a yes or no on ovulation. If the first result is borderline, repeat it in two or three cycles at the same lab, because immunoassay and mass-spectrometry (LC-MS/MS) results are not interchangeable. Why repeats beat one reading: trends vs single results.
Example mid-luteal progesterone resultng/mL
| Phase | Typical ng/mL | Typical nmol/L | What a low number means |
|---|---|---|---|
| Follicular (before ovulation) | Under 1 | Under 3 | Expected. Says nothing about ovulation. |
| Mid-luteal (about 7 days before period) | 3 to 25 | 10 to 80 | Under 3 ng/mL suggests no ovulation that cycle, or a mistimed draw. |
| First trimester | 10 to 45 | 32 to 140 | Read only with hCG (the pregnancy hormone a pregnancy test detects) and a scan, never alone. |
| On the combined pill, patch, ring, implant or injection | Under 1 | Under 3 | Expected. Ovulation is usually suppressed by design. |
| Hormonal (levonorgestrel) IUD | Varies | Varies | Many users still ovulate, so read it like a natural cycle. |
| Postmenopause | Under 0.5 | Under 1.6 | Expected. |
| Men | Under 1 | Under 3 | Expected. Rarely tested. |
Why is my progesterone low? The common causes
The most common cause of a low progesterone result is a draw on the wrong day. After that, almost every cause works by stopping or shortening ovulation.
- Mistimed blood test: drawn before ovulation, or on day 21 in a cycle longer than 28 days.
- Hormonal contraception: the combined pill, patch, ring, implant and injection usually stop ovulation. Hormonal IUDs mostly act on the uterine lining and many users still ovulate; copper IUDs never stop it. The synthetic progestins in contraception do not show up on a progesterone test.
- Breastfeeding: high prolactin holds ovulation off for months.
- PCOS: irregular ovulation is one of its defining features.
- Under-eating, heavy training or prolonged stress: functional hypothalamic amenorrhea, where the brain cuts the hormone pulses that trigger ovulation 3.
- Thyroid disease: both an underactive and an overactive thyroid disturb cycles; see hypothyroidism and hyperthyroidism.
- High prolactin from medication or a pituitary adenoma (a benign pituitary growth).
- Perimenopause and menopause.
What is usually checked beside a low progesterone
Low progesterone after 40: the perimenopause pattern
Low progesterone after 40 is mostly a perimenopause pattern. From the late 30s and through the 40s, more cycles pass without ovulation. Progesterone becomes erratic years before estrogen falls, and estrogen can still surge in cycles where no egg is released. The typical pattern is cycles that come closer together or skip, heavier periods, more premenstrual spotting, and worse sleep in the second half of the cycle. One progesterone test in perimenopause means little, since next month may be ovulatory; the pattern of your periods over 6 to 12 months tells you more. How perimenopause is diagnosed and treated is on the perimenopause page.
Low progesterone in early pregnancy
In early pregnancy, a low progesterone is usually a sign that the pregnancy is already failing, and rarely the cause. In women with pain or bleeding and a scan that cannot yet confirm a healthy pregnancy, a single serum progesterone below roughly 3.2 to 6 ng/mL strongly predicts a non-viable pregnancy, in a BMJ meta-analysis of 26 studies 6. That cutoff is used alongside hCG and ultrasound, never on its own.
Progesterone treatment helps a narrow group. In the PROMISE trial of women with unexplained recurrent miscarriage, progesterone started as soon as a pregnancy test was positive did not raise live births (65.8% vs 63.3%) 8. In the PRISM trial of 4,153 women with bleeding in early pregnancy, vaginal progesterone did not significantly raise live births overall (75% vs 72%); in the subgroup with three or more previous miscarriages, live births were higher (72% vs 57%) 5. That is a decision for an obstetrician, made with your history, and not a reason to start progesterone yourself.
How and when to test progesterone
NICE advises testing progesterone in the mid-luteal phase, about 7 days before the expected period, in women with regular cycles. In women with long irregular cycles, NICE advises testing later in the cycle and repeating weekly until the next period starts 2. Day 21 only works for a 28-day cycle. If your cycle is 32 days, the right day is around day 25.
- 1Find your expected period dateCount from the first day of your last period using your usual cycle length.
- 2Count back 7 daysThat is the draw day. If you use LH test strips, 7 days after a positive strip works too.
- 3Pause high-dose biotinStop hair, skin and nail supplements before the draw for as long as the lab advises.
- 4Note the cycle day on the resultA number without a cycle day cannot be read. Write down the day of the draw and the date your next period starts.
- 5Repeat if cycles are longRepeat weekly until your period arrives, or test again next cycle.
CalculatorOvulation calculatorWorks out your likely ovulation day so you can pick the mid-luteal draw day.Work it out A supplement that can distort the test
Saliva hormone tests are not used to guide treatment, because they track blood levels poorly. A progesterone test on the combined pill, patch, ring, implant or injection will usually read low and tells you little; on a hormonal IUD the result depends on whether you ovulated that cycle. If pregnancy is possible, a pregnancy test comes first. The female hormone panel explainer shows how progesterone, estradiol, LH and FSH read together.
How to increase progesterone levels naturally
The body raises progesterone by ovulating, so the levers are the things that restore ovulation. Eating enough to match training, cutting back very high training loads and easing psychological stress can bring ovulation back in functional hypothalamic amenorrhea, which the Endocrine Society guideline treats as the first-line approach 3. Treating an underlying thyroid problem, high prolactin or PCOS restores ovulation in many women.
No food contains progesterone that your body can use, and no supplement reliably raises blood progesterone. Vitex (chasteberry) eased PMS symptoms more than placebo in a three-cycle trial of 170 women (52% vs 24% responders) 7, and vitamin B6 has some evidence for PMS, but neither has been shown to raise serum progesterone. Over-the-counter progesterone creams are poorly regulated, their absorbed dose is unpredictable, and they should not be relied on to protect the uterine lining if you take estrogen. Prescribed progesterone has defined uses: fertility treatment, hormone therapy alongside estrogen to protect the uterine lining, and some pregnancies. All of those are started by a doctor.
When to see a doctor
- Periods absent for 3 months or more, and you are not pregnant or breastfeeding.
- Cycles regularly shorter than 21 days or longer than 35 days.
- Bleeding between periods, after sex, or any bleeding after menopause.
- Trying to conceive for 12 months, or 6 months if you are 35 or older. The fertility page covers which tests are usually run.
- Very heavy bleeding: soaking a pad or tampon every hour for several hours, or passing large clots. Seek same-day care if you also feel faint.
- Any bleeding or pain in pregnancy.
Citations
- ASRM Practice Committee. Diagnostic evaluation of the infertile female: a committee opinion. Fertility and Sterility 2015;103(6):e44-50.
- National Institute for Health and Care Excellence. Fertility problems: assessment and treatment (CG156), 2013, updated 2017.
- Gordon CM et al. Functional Hypothalamic Amenorrhea: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism 2017;102(5):1413-1439.
- Schmidt PJ et al. Differential behavioral effects of gonadal steroids in women with and in those without premenstrual syndrome. New England Journal of Medicine 1998;338:209-216.
- Coomarasamy A et al. A randomized trial of progesterone in women with bleeding in early pregnancy (PRISM). New England Journal of Medicine 2019;380:1815-1824.
- Verhaegen J et al. Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding: meta-analysis of cohort studies. BMJ 2012;345:e6077.
- Schellenberg R. Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study. BMJ 2001;322:134-137.
- Coomarasamy A et al. A randomized trial of progesterone in women with recurrent miscarriages (PROMISE). New England Journal of Medicine 2015;373:2141-2148.
- Practice Committee of the American Society for Reproductive Medicine. Diagnosis and treatment of luteal phase deficiency: a committee opinion. Fertility and Sterility 2021;115(6):1416-1423.
Educational context only, not medical advice or a diagnosis. Always discuss your results with a clinician.
