Progesterone is a steroid hormone involved in the menstrual cycle, pregnancy, and embryo development in humans. It is formed in the corpus luteum during early pregnancy and the placenta during late pregnancy. Progesterone binds to receptors found throughout the body, including the central nervous system, endocrine system, and reproductive system. Physiologically, progesterone prepares the uterus for pregnancy, prevents uterine contractions, and supports the corpus luteum until the placenta can secrete progesterone in later stages of pregnancy. Normal progesterone levels fluctuate throughout the menstrual cycle and pregnancy. Both low and high progesterone can cause various symptoms and may be due to conditions like hypothyroidism, menopause, or cancers.

1. Progesterone
Omar Aljabri
(Master student in the Department of Laboratories, King Saud
University, Riyadh.)

2. Progesterone
oProgesterone is an endogenous steroid hormone involved in
menstrual cycle ,pregnancy & embryogenesis of humans.
oProgesterone is also important metabolic intermediate in the
production of other endogenous steroids.
oplays an important role in brain function as a neurosteroid.
Formed in:
• CORPUS LEUTEUM:in the early pregnancy .
• PLACENTA:in the late pregnancy period.
• TESTES
• ADRENAL CORTEX

3. Biosynthesis
In mammals, progesterone, like all other steroid hormones, is
synthesized from pregnenolone, which itself is derived from
cholesterol.

4. Distribution And receptors
Progesterone binding is
distributed as follows:
1) Approximately 18% of serum
progesterone is bound to
transcortin(corticosteroid-
binding globulin (CBG)
2) the another 80% of it is
bound to serum albumin.
3) The remaining 2% is free
 PR is expressed in the following organs:
1-central nervous system (CNS) 2- Endocrine
3-gastrointestinal 4-immune 5-reproductive 6-
cardiovascular 7-respiratory

6. Physiological and metabolic effect.
Physiological:
1. prepares the endometrium pregnancy
2. It triggers the lining to thicken to
accept a fertilized egg
3. prohibits the muscle contractions in
the uterus
4. If no fertilization occurs the corpus
luteum breaks down, lowering the
progesterone levels in the body.
5. During the 7-10 week of pregnancy, the
placenta begins to secrete
progesterone.supporting the corpus
luteum.
6. It also helps prepare the breasts for
milk production.
Metabolic:
1. important effects on carbohydrate,
lipid and protein metabolism.
2. promoting glycogen storage in the liver
3. antagonizes the effects of insulin on
glucose metabolism in adipose tissue
4. stimulates deposition of body

7. Normal values of progesterone hormone
Normal values of progesterone hormone for non - pregnant women Average
monthly days 28 days
Days from 1 - 6 Less than 100 ng/dL Less than 1 ng/mL
Days from 7 - 14 20 – 150 ng/dL 0.2 – 1.5 ng/mL
Days from 15 - 28 250 – 2800 ng/dL 2 – 28 ng/mL
Normal values of progesterone in pregnancy
first third 900 – 4700 ng/dL 9 – 47 ng/mL
second third 1700 – 14700 ng/dL 17 – 147 ng/mL
The last third 5500 – 20000 ng/dL 55 – 200 ng/mL
Normal values of progesterone hormone after menopause
Less than 40 ng/dL Less than 1ng/mL

8. Low Progesterone levels
Symptoms of low
Progesterone Levels
Menstrual irregularities.
Fibrocystic breasts:usually
noncancerous.
Difficulty Getting Pregnant.
 Difficulty Staying Pregnant.
Anxiety.
low progesterone levels can
be caused by:
Untreated Hypothyroidism
Adequate thyroid hormone and
function is required for both
regular ovulation and
progesterone production in the
body
 Age around age 35
progesterone levels will start to
drop until menopause
 Menopause

9. High Progesterone Levels
Symptoms of High
Progesterone Levels
Anxiety
Bloating
Urinary infections
Loss of libido
Weight gain
high progesterone levels can
be caused by:
ovarian cancer
adrenal cancer
congenital adrenal
hyperplasia