Progesterone is a rather important steroid hormone, that is classified in the group of progestogen compounds, which plays a central role in the processes of menstruation and fertility in women. It is a vital reproductive hormone along with estrogen and is secreted primarily by the corpus luteum, a temporary endocrine assembly synthesized by the ovaries during the menstrual cycle, throughout the sexually active phase from puberty until menopause. Besides the ovaries, a small amount of progesterone is also produced in the adrenal glands, which are situated directly above the kidneys, as well as the placenta, a specialised organ that is formed in the uterus during pregnancy.
Also Read: Estrogen: Structure, Crucial Functions, Adverse Effects
Although progesterone is fundamentally a chief female reproductive hormone, it is also synthesized in males, to aid in optimal sperm development operations. In women, the generation of luteinizing hormone by the anterior pituitary gland increases amid an ongoing menstrual cycle, which stimulates ovulation - an egg to be released from either one of the two ovaries. This influences the formation of the corpus luteum and the subsequent production of the progesterone hormone in the ovaries. Depending on whether the egg is eventually fertilized or not, progesterone nurtures embryo development in pregnancy or regulates normal periods accordingly.
Progesterone And Its Structure:
The presence of the reproductive hormone progesterone was discovered by two renowned American medical researchers –physician George Washington Corner and gynaecologist Willard Myron Allen in the year 1930. Continuing their groundbreaking studies on the roles of this hormone and its possible applications in medicine and therapy, these two scientists were also among the first to isolate and purify the crystalline residues of progesterone in 1933. Eventually, the chemical structure of progesterone was deduced by the prominent German biochemist Adolf Butenandt in 1934, for which he was conferred the prestigious Nobel Prize in Chemistry in the year 1939.
Progesterone hormone in humans produced from a precursor substance called pregnenolone, which is derived from cholesterol. It is essentially a steroid hormone belonging to the progestogen class of biochemical compounds, comprising a bioactive structure of four rings made up of predominantly carbon, hydrogen, oxygen molecules bonded together in a particular arrangement. The molecular formula of progesterone is C21H30O2 and it has a molar mass of 314.469 g/mol (grams per mole), with mole being the international standard unit for measuring the molecular weight of chemical compounds.
Functions Of Progesterone:
The chemical messenger and hormonal compound progesterone is involved in numerous vital roles in the body, such as:
- Regulating menstrual cycles in adolescence and adulthood and averting instances of irregular periods
- Promoting the normal development of breasts in women, along with estrogen
- Ensuring a healthy pregnancy and optimal nourishment of the developing foetus
- Maintaining hormonal functions in women at the onset of menopause, along with estrogen
- Supporting healthy sperm development in males, although being produced in very small amounts in men
- Enhancing skin elasticity and slowing down ageing in menopausal women, along with estrogen
- Boosting immunity by conferring anti-inflammatory and cytoprotective i.e. safeguarding cells properties
- Promotes smooth relay of signals via nerves, uplifts brain functions and lowers the risk of stroke
Adverse Effects On Imbalance In Progesterone Levels:
Low Levels
Low levels of progesterone result in irregular periods, cases of amenorrhea, as well as spotting, severe abdominal pain during pregnancy. It also heightens the risk of miscarriage and leads to sudden excessive weight gain.
At times, low levels of progesterone trigger very high amounts of estrogen in the bloodstream. This in turn causes liver complications, gall bladder issues as well as increased sex drive or libido in women.
High Levels
There are no grave complications that arise from very high levels of progesterone. The circulating concentrations of this hormone are inherently increased during pregnancy to support the growing nutritional needs of the gestating woman and developing foetus. However, too much progesterone synthesis is associated with a rare birth defect in newborns – congenital adrenal hyperplasia, as well as increased risk of breast cancer in middle-aged and elderly women.
Also Read: Breast Cancer: Causes, Symptoms And Treatment
Nevertheless, progesterone levels in most instances are regulated by the anterior pituitary gland, to preserve female reproductive functions of menstruation, pregnancy and do not become very high.
Frequently Asked Questions
How is low progesterone treated?
Treatment for low progesterone levels depends on the underlying cause and may include lifestyle changes, such as stress reduction and dietary modifications, hormone replacement therapy (HRT), fertility medications, or supplements containing natural progesterone or herbs that support progesterone production.
Can progesterone be used as birth control?
Progesterone-only birth control methods, such as progesterone-only pills, injections, implants, and intrauterine devices (IUDs), are available and work by thickening cervical mucus, making it difficult for the sperm to reach the ovum. This thins the uterine lining, preventing implantation and pregnancy.
Are there any side effects of the progesterone therapy?
Side effects of progesterone therapy may include bloating, breast tenderness, mood changes, headaches, nausea, dizziness, and changes in menstrual bleeding patterns. In pregnant women, progesterone therapy may increase the risk of blood clots or gestational diabetes.
Is progesterone hormone therapy safe during pregnancy?
Progesterone hormone therapy is commonly used during pregnancy to support early pregnancy and reduce the risk of miscarriage in women with a history of recurrent miscarriages or certain risk factors. When used as prescribed, progesterone therapy is generally considered safe during pregnancy.
Can progesterone levels fluctuate during the menstrual cycle?
Yes, progesterone levels naturally fluctuate during the menstrual cycle, rising after ovulation to prepare the uterine lining for implantation and declining if pregnancy does not occur, leading to the shedding of the uterine lining during menstruation. Tracking progesterone levels can help assess ovarian function and fertility.
References:
- Physiology, Progesterone - By Jessie K. Cable; Michael H. Grider.
https://www.ncbi.nlm.nih.gov/books/NBK558960/
- Key to Life: Physiological Role and Clinical Implications of Progesterone - By Bernadett Nagy,1,2,3,* Júlia Szekeres-Barthó,1,3,4,5 Gábor L. Kovács,1,4,6 Endre Sulyok,1,7 Bálint Farkas,1,2,3 Ákos Várnagy,1,2,3 Viola Vértes,1,2 Kálmán Kovács,1,2,3,† and József Bódis1,2,3,†
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8538505/
