What are the first signs of low progesterone?

Changes in your periods are usually the first sign: cycles that become irregular, shorter or heavier, or spotting before your period. Because these have several causes, a timed blood test and other labs help find the reason.

Can low progesterone cause weight gain?

Low progesterone is not a known cause of weight gain on its own. Conditions that lower progesterone, such as PCOS, thyroid problems and the menopause transition, are linked with weight changes, so those are what Dr. Munib checks.

Can low progesterone cause anxiety or poor sleep?

Some women notice worse sleep or mood in the days before a period or in perimenopause, when progesterone is falling. These symptoms have many causes, so they are looked at alongside thyroid levels, iron, stress and mood.

When should I get a progesterone blood test?

About 7 days before your next expected period, which is around day 21 in a 28-day cycle. If your cycle is longer or irregular, the timing shifts and the test may need to be repeated.

What is a normal progesterone level on day 21?

A level above about 3 ng/mL in the second half of the cycle usually means you ovulated that month. Results depend on timing, so one low number is not a diagnosis on its own.

Does progesterone cream work for low progesterone?

Over-the-counter progesterone creams are not FDA-approved and the amount absorbed varies. They do not provide enough progesterone to protect the uterus if you take estrogen.

Should I see my OB for low progesterone in pregnancy?

Yes. Progesterone questions during pregnancy or fertility treatment should be managed by your OB or fertility doctor, and Dr. Munib refers these patients to an OB.

Low Progesterone Symptoms, Tests & Care

The most common low progesterone symptoms are irregular or missed periods, heavy or long periods, spotting before your period and, for some women, trouble getting pregnant. Low progesterone usually means ovulation is not happening regularly, which is common with PCOS, thyroid problems and perimenopause. A blood test timed to the second half of your cycle can show whether you ovulated, and treatment depends on the cause and your goals.

What does progesterone do?

Progesterone is made mainly by the ovary after an egg is released. Each month it prepares the lining of the uterus. If you do not get pregnant, progesterone falls and your period starts. If you do, it helps support the early pregnancy.

Because progesterone is made after ovulation, a low level in the second half of the cycle usually means one of two things: you did not ovulate that month, or the phase after ovulation was short. It is less a disease of its own and more a sign that something is changing how your cycle works.

What are the symptoms of low progesterone?

The clearest signs show up in your periods, because without progesterone the lining of the uterus builds up and sheds unevenly.

Irregular periods, or cycles that change length a lot from month to month
Missed periods, or periods that stop for months
Heavy or long periods, sometimes with clots
Spotting in the days before your period
Short cycles, with periods coming closer together
Trouble getting pregnant

Many women also link low progesterone with poor sleep, mood changes, anxiety, headaches or breast tenderness before a period. These symptoms are real, but they have many other causes, including thyroid problems, low iron, stress and depression. That is why a doctor looks at the whole picture instead of blaming one hormone.

Low progesterone symptoms by life stage

During your regular cycling years

In your 20s and 30s, low progesterone usually comes from cycles where you do not ovulate. Common reasons include:

PCOS (polycystic ovary syndrome), often with irregular periods, acne or extra hair growth
An underactive or overactive thyroid
A high prolactin level
Big changes in weight, very intense exercise, under-eating or a lot of stress
Stopping hormonal birth control, while cycles settle back down

In perimenopause

Perimenopause is the few years before your last period, often starting in the 40s. Ovulation becomes less regular, so progesterone drops in some months while estrogen can still swing high. This is why many women in their 40s notice heavier, closer or more irregular periods, along with hot flashes, night sweats and broken sleep.

Read what perimenopause is and how it is treated in our hormone replacement guide

After menopause

After your last period, the ovaries stop releasing eggs, so progesterone stays low for everyone. That is expected and does not need testing. Progesterone matters after menopause mainly if you take estrogen and still have a uterus, because it protects the lining of the uterus.

Low progesterone in pregnancy

If you are pregnant or trying to get pregnant and are worried about progesterone, your OB or fertility doctor is the right person to manage it. Dr. Munib refers pregnancy-related progesterone questions to an OB. In early pregnancy, a low level is often a sign that a pregnancy is not developing normally rather than the cause of it, and the next steps depend on an exam and ultrasound.

If you are pregnant and have heavy bleeding, severe pain on one side, shoulder pain or feel faint, go to the emergency room. These can be signs of an ectopic pregnancy.

How do you test for low progesterone?

Progesterone is checked with a simple blood test. Timing matters more than for most labs, because the level is low before ovulation and rises only afterward.

Why the day 21 test is timed the way it is

The test is meant to be drawn about 7 days before your next period, when progesterone should be at its peak. In a 28-day cycle that falls on about day 21, which is where the name comes from.

If your cycle is 28 days, test on about day 21 (day 1 is the first day of bleeding)
If your cycle is 35 days, test on about day 28
If your cycle is very irregular, the test may need to be repeated, or timed once your next period starts so you can count back

A level above about 3 ng/mL in the second half of the cycle usually means you ovulated that month.

Why progesterone levels vary

Levels change across the cycle, so a test on the wrong day can look low even when you ovulate normally
Progesterone is released in pulses, so two tests a few hours apart can differ
Ovulation does not happen every month, especially in perimenopause or with PCOS
Birth control pills, progesterone pills and some other medicines change the result

Because of this, one low result is not a diagnosis. Dr. Munib reads it alongside your period history and other labs, which may include a pregnancy test, thyroid tests, prolactin and, if PCOS is possible, androgen levels. Saliva and home hormone kits are not reliable for this.

What are the treatment options for low progesterone?

Treatment depends on why progesterone is low and what you want help with: regular periods, lighter bleeding, symptom relief or protecting the uterus while on estrogen. Treating the cause comes first. For example, correcting a thyroid problem or managing PCOS can bring back regular cycles.

Oral progesterone

Micronized progesterone capsules are an FDA-approved form of progesterone that is identical to the hormone your body makes. They are used to bring back periods that have stopped, and to protect the lining of the uterus in women who take estrogen after menopause.

Taken at bedtime, often for part of each month
It can cause drowsiness or dizziness, so be careful driving until you know how it affects you
Some capsules contain peanut oil, so tell Dr. Munib about a peanut allergy
It is not right for people with unexplained vaginal bleeding, a history of breast cancer, a past blood clot or stroke, or liver disease

A combination patch with estrogen and progestin

For women in or past menopause who still have a uterus and need estrogen for hot flashes or night sweats, a combination patch delivers estrogen and a progestin, a form of progesterone, together. One patch covers both, applied to the skin on a set schedule.

What about progesterone cream from the store?

Over-the-counter progesterone and wild yam creams are not FDA-approved, and the amount absorbed varies. They do not deliver enough progesterone to protect the uterus if you take estrogen. If you are using one, bring it to your visit.

Learn more about the side effects of taking progesterone

When should you see a doctor?

Your periods have stopped for 3 months or more and you are not pregnant
You soak through a pad or tampon every hour for several hours, or pass large clots
You bleed between periods or after sex
You have any bleeding after menopause
You feel very tired, short of breath or dizzy with heavy periods, which can mean low iron
You have been trying to get pregnant for a year, or 6 months if you are 35 or older

How Dr. Munib approaches low progesterone

Dr. Munib starts with your story: your cycle pattern, bleeding, sleep, mood, weight changes, medicines and whether pregnancy is a goal. She may order a timed progesterone test and other labs to find the cause, rather than treating a single number.

From there, the options she may discuss depend on your age and health history. They may include treating a thyroid or PCOS problem, oral progesterone, birth control to regulate periods, or, in perimenopause and menopause, hormone therapy such as a combination patch. Pregnancy-related concerns are referred to an OB. Follow-up visits check how your periods and symptoms respond and adjust the plan.

See all hormone care at The Pur Health

If irregular or heavy periods, or symptoms you think are hormonal, are affecting your life, book a visit with Dr. Munib at 114 Pacifica, Suite 280, Irvine. We are in-network with most PPO plans, HSA and FSA cards are accepted, and no referral is needed. Cash visits are $190 for new patients and $150 for returning patients.

Low Progesterone Symptoms: Signs by Life Stage, Testing and Treatment