Progesterone is a sex hormone that supports menstruation and pregnancy in women or people assigned female at birth (AFAB). Low levels of progesterone cause symptoms like irregular periods, mood changes and trouble conceiving.
Progesterone is a hormone that plays an important role in your reproductive system. Hormones are chemical messengers that tell your body how to work. In women or people assigned female at birth (AFAB), progesterone supports menstruation and prepares your uterus for pregnancy. If your progesterone levels are low, it can cause irregular menstruation, make it difficult to maintain a pregnancy and affect your overall health.
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Some of the functions of progesterone in your body include:
Progesterone is critical in supporting a pregnancy because it thickens your uterine lining (called the endometrium). A thick uterine lining helps a fertilized egg implant and grow.
Progesterone is made by your ovaries (with support from your adrenal glands). More specifically, the corpus luteum, the empty follicle in your ovary that releases an egg during ovulation. If an egg is fertilized by sperm at ovulation, human chorionic gonadotropin (HCG) tells the corpus luteum to make more progesterone to support the developing embryo.
Progesterone levels continue to rise during pregnancy. It also suppresses uterine contractions, which helps you avoid preterm labor. Finally, it helps your mammary glands (breasts) prepare for breastfeeding (chestfeeding).
Progesterone is responsible for thickening your uterine lining to prepare it for pregnancy. If conception doesn’t occur during that menstrual cycle, progesterone levels drop, and you get your period. The blood and discharge you see during your period is your uterine lining breaking down.
Only your healthcare provider can determine if your progesterone levels need to be checked. Hormones are a complex system in your body. Too little or too much of one hormone causes a chain reaction in the rest of your hormones.
In the case of progesterone, it’s balanced by estrogen. Having low progesterone can lead to having too much estrogen, which can cause symptoms like:
If you’re trying to get pregnant, low progesterone levels could make it hard to maintain a pregnancy.
Low progesterone affects your body’s ability to create a thick and healthy uterine lining. This lining is what a fertilized egg attaches to. Once it attaches, more progesterone is needed to help grow the embryo into a fetus.
Since progesterone plays an important role in maintaining your uterine lining during pregnancy, low levels can make it hard for you to stay pregnant. You need progesterone levels to stay high until you’re ready to give birth.
If you have low progesterone, you’re at risk for pregnancy complications, such as:
Low progesterone can affect your body in several ways and cause unpleasant symptoms in some people.
Symptoms of low progesterone in people who aren’t pregnant include:
Some symptoms of low progesterone in pregnant people are:
There are several causes of low progesterone. The most common causes are:
Men or people assigned male at birth (AMAB) don’t require as much progesterone as women or people AFAB. However, low levels of progesterone can still affect their bodies. Some signs of low progesterone in men are:
A blood test (a PGSN or progesterone test) diagnoses low progesterone. Progesterone levels fluctuate, and there’s a wide range of acceptable levels. Your healthcare provider may measure your progesterone levels if you’re trying to conceive and have issues with ovulation or regular menstruation.
Progesterone levels fluctuate during your menstrual cycle and are affected by your age and whether or not you’re pregnant.
In the follicular phase of your cycle (the first half of your cycle), progesterone levels are low. You can expect levels of less than 2 nanograms per milliliter (ng/mL) of blood.
At ovulation, progesterone rises, and its levels peak about one week after ovulation (during the luteal phase of your cycle). Your progesterone levels may rise to around 20 ng/mL. If you’re not pregnant, progesterone levels drop, and you can expect to get your period within a few days.
If you’ve conceived that menstrual cycle, progesterone levels continue to increase. During the first trimester of pregnancy (up until the 13th week of pregnancy), progesterone levels can be as high as 90 ng/mL. By the time you enter your third trimester, progesterone levels may be as high as 300 ng/mL. Progesterone levels are higher if you’re expecting multiples.
Like other reproductive hormones, progesterone levels decrease as you age and enter menopause. After menopause, your progesterone levels may fall below .5 ng/mL.
You can’t check progesterone levels at home. Only your healthcare provider can check your progesterone levels using a blood test.
There are several ways your healthcare provider can treat low progesterone depending on your symptoms and goals. For example, if you’re trying to get pregnant, progesterone may be needed to thicken your uterine lining. During menopause, you may need progesterone (and estrogen) to help reduce your symptoms.
Progesterone is available in a few different forms:
Progesterone supplements are low-risk; however, each treatment has side effects and risks. Talk to your healthcare provider to make sure you understand the risks and benefits of progesterone treatment.
Some of the following options are safe and may help increase progesterone levels:
Contact your healthcare provider if you have any of the following symptoms:
Symptoms of low progesterone are similar to other conditions, so it’s important to talk to your healthcare provider for an accurate diagnosis.
A note from Cleveland Clinic
Progesterone is an important hormone in your body. It helps regulate menstruation and supports a pregnancy. Low levels of progesterone can cause irregular menstrual periods, spotting and headaches, and could affect your ability to get pregnant. Speak with your healthcare provider if you notice symptoms of low progesterone. They may want to run blood tests, especially if you’re trying to conceive. There are many treatments for low progesterone that you can discuss with your provider.
Last reviewed by a Cleveland Clinic medical professional on 01/16/2023.
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