Although it is true that several hormones are traditionally labeled as “female” hormones, men also produce them, simply in lower amounts. One of most well-known of these hormones is progesterone.

Despite popular familiarity with the progesterone hormone, many women remain uncertain as to what role it performs within the body. In order to make informed decisions about health, understanding what is progesterone, its definition, and the different types of progesterone is essential.

What Is Progesterone?

Progesterone Definition

Progesterone is defined as a major progestational steroid hormone that prepares the uterus for a fertilized ovum and maintains pregnancy.

progesterone hormone

Throughout the menstrual cycle, progesterone is principally secreted by the corpus luteum to prepare the endometrium for implantation. If conception does not occur, the corpus luteum breaks down and triggers the beginning of the next menstrual cycle. However, if conception does occur, then the placenta takes control of progesterone secretion, which prevents the rejection of the developing embryo.
Accordingly, progesterone is produced in the ovaries and placenta to foster healthy menstruation, embryonic development, and pregnancy. However, the sex hormone is also produced in the adrenal glands. More complete information on progesterone's production in glands and receptors is elaborated upon in its own page.

Since progesterone is so intricately involved with a woman's reproductive life, a progesterone imbalance can evoke infertility and problems with menstruation. While different levels will be produced in a woman's body depending on her reproductive stage, maintaining hormonal balance is essential to overall health.

Progesterone Meaning: Word Origin

Initially, the name progesterone was a blend of progestin and luteosterone (corpus luteum + sterol).

However, now the origin of the word progesterone is claimed to be a combination of a physiological and chemical description: progestational steroidal ketone.

Types of Progesterone?

There are two main types of progesterone hormones: steroidal and non-steroidal.

Steroidal progesterone hormones are endogenous, originating from within women. Non-steroidal progesterone hormones are pharmaceutically-made and derived from natural sources, such as plants.

Steroidal Hormones - Naturally Occurring in Women


Lipid-soluble, steroid hormones can penetrate and enter target cells to directly affect cell behavior. These types of hormones are also created from cholesterol.
Progesterone is a steroid hormone that belongs the progestogens, which are derived from pregnenolone. In fact, progesterone is the only naturally occurring human progestogen.

Pregnenolone is an endogenous steroid hormone that is a principal precursor to other steroid hormones synthesized by the ovaries and adrenal glands. There are four major classes of steroids obtained from pregnenolone: estrogens, progestogens, androgens, and corticosteroids. The first three classes are considered sex steroid hormones.

Keep in mind that progesterone should not be confused with progestins, which are synthetically produced progestogens.

Progesterone Structure (C21H30O2)

progesterone hormones

Steroid hormones, such as progesterone, have four cyclic hydrocarbons. Each hydrocarbon is an amalgamation of hydrogen and carbon and is hydrophobic, repelled by water.

Moreover, the structure of progesterone consists of ketone and oxygenated functional groups as well as two methyl branches.

Non-steroidal Hormones - Synthetic or Derived from Plants

Also, recall that non-steroid hormones need an enzyme or other method of transport to relay information to the interior of a cell, subsequently causing a reaction. Depending on how the hormones are created, some synthetic steroids can be weaker or stronger than natural steroids whose receptors they activate.

In regards to progesterone hormones, there are a couple main types of non-steroid, synthetically-produced progesterone, those for birth control and HRT.

Progesterone for Birth Control

Progestin hormones are produced in laboratories to have progestogenic activity that triggers effects similar to those of endogenous progesterone.

Progestin-only pills are used as contraceptives for women with contraindications to estrogen or for those breast-feeding. Combination oral contraceptive pills with progestin and estrogen are used to reduce androgenic symptoms.

Moreover, progestin hormones act on the uterus - especially in treatment of dysfunctional uterine bleeding and prevention of endometrial cancer - and the mammary glands in preparation for and in maintenance of pregnancy.

Medications are available in various forms, including the pill; topical applications, such as creams and skin patches; injections into a muscle; or insertions, such as vaginal rings or intrauterine devices.

Noted side effects of progestin contraceptive pills include breakthrough bleeding, nausea, headaches, breast tenderness, acne, mood swings, weight gain, hirsutism, and more.

Because of reported side effects, interest in replicating the progesterone hormone for clinical use from plant sources instead has ensued.

Progesterone for HRT

Natural progesterone is produced from plant sources, such as wild Mexican yam and soybeans. A chemical known as diosgenin is isolated from the plant sources to first be converted to pregnenolone and then progesterone. Since the human body cannot make progesterone from diosgenin itself, this process first needs to be performed in a laboratory before the plant-based progesterone is ready for use.

Additionally, natural progesterone is used for bioidentical hormones in progesterone replacement therapy. Since the type of progesterone produced is molecularly identical to endogenous progesterone, bioidentical hormones fill the hormonal void when possible.

Bioidentical progesterone is available in various forms, including injectable, intravaginal, topical, and oral formulations.

Noted side effects from the use of natural progesterone include drowsiness or insomnia; appetite changes; allergic skin reactions; fevers; headaches; depression; fluid retention; fatigue; acne; and more.

However, when compared to synthetically-produced progestin hormones, natural progesterone has improved bioavailability with reportedly fewer side effects.

Continue reading to learn all about explicative information on progesterone production in glands and receptors for an improved fundamental understanding of the hormone's importance in the female body.


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