Posted on 14 Comments

Progesterone: The Other Female Hormone!

Pic created @

Progesterone: the other main hormone responsible for fertility and menstruation. Progesterone is a steroid hormone belonging to a class of hormones called progestogens.

It is secreted by the corpus luteum, a temporary endocrine gland that the female body produces after ovulation during the second half of the menstrual cycle.

Synthetic steroid hormones with progesterone-like properties are called progestins. 

What Does Progesterone Do?

Progesterone hormone prepares the uterus lining for the potential of pregnancy after ovulation. It triggers the lining to thicken to accept a fertilized egg.

It also prohibits the muscle contractions in the uterus that would cause the body to reject an egg. While the body is producing high levels of progesterone, the body will not ovulate.

If the woman does not become pregnant, the corpus luteum breaks down, lowering the progesterone levels in the body. This change sparks menstruation.

If the body does conceive, progesterone continues to stimulate the body to provide the blood vessels in the endometrium that will feed the growing fetus. The hormone also prepares the lining of the uterus further so it can accept the fertilized egg.

Once the placenta develops, it also begins to secrete progesterone, supporting the corpus luteum. This causes the levels to remain elevated throughout the pregnancy, so the body does not produce more eggs. It also helps prepare the breasts for milk production.

Progestin What Can It Do?

Progestin (a synthetic version of the progesterone hormones) can also be used to treat menopause symptoms such as hot flashes and vaginal dryness.

Estrogen is often combined with progestin and together they serve to inhibit the maturation of the egg follicle more effectively — as well as discourage ovulation. So they are used as contraception (prevent pregnancy).

For women who are peri-menopausal or newly menopausal, healthcare providers may suggest an oral micronized progesterone treatment.

Progestin can also be prescribed to treat amenorrhea (absence of your menstrual cycle), endometriosis (growth of uterine-like tissue outside of the uterus), and irregular periods. (A little interesting side note).

Progesterone Levels

Progesterone levels are measured by blood tests. Please keep in mind that the levels fluctuate throughout the menstrual cycle, so the levels will vary.

Progesterone levels are measured in nanograms per millilitre (ng/mL). Please see the below chart for reference levels of progesterone for an adult female during different points of the menstrual cycle and pregnancy.

StageProgesterone level (ng/mL)
pre-ovulation< 0.89
ovulation≤ 12
first trimester11–44
second trimester25–83
third trimester58–214
Chart from

Progesterone & Men

Progesterone is also produced in the adrenal glands of males. The known function is associated with sperm development.

High Progesterone

High progesterone in a non-pregnant female could be a sign of a diagnosed health issue. This could include:

  • ovarian cysts
  • congenital adrenal hyperplasia (an inherited condition with your adrenal glands)
  • ovarian cancer
  • adrenal cancer

Low Progesterone

Low levels of progesterone will cause a woman to have abnormal menstrual cycles and she may struggle to conceive as low levels of progesterone will not trigger the proper environment for a conceived egg to grow.

Symptoms of low progesterone are:

  • Abnormal uterine bleeding
  • Irregular or missed periods
  • Spotting and abdominal pain during pregnancy
  • Frequent miscarriages
  • Problems with fertility
  • Decreased libido
  • Weight Gain

Women whose levels are low do succeed in getting pregnant are at higher risk for miscarriage or preterm delivery, due to a lack in the amount of hormone requires to maintain a pregnancy.

If you take progestin to treat menopausal symptoms, for birth control, or to treat other conditions side effects may occur. Some of these side effects are dosage dependent, and how your body processes the synthetic hormone.

Progestin for menopause

Side effects may include;

  1. Mood changes
  2. Bloating
  3. Headaches
  4. Breast tenderness
  5. For newly menopausal women, breakthrough bleeding.

To feel at our optimum, the delicate hormone homeostasis must be achieved as hormones are the brains behind all the processes of the body.

If you have any medical concerns, please be sure to discuss this with your care provider.

You can click this link to read about estrogen,

And black cohosh and its role in a woman’s life at;

Rites of passage, a menopause story at;

Sources Cited:

Mayo clinic

Hormone Health Network.”Progesterone | Endocrine Society.”, Endocrine Society, 10 February 2020,