Names | |
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IUPAC name | |
Systematic IUPAC name (1S,3aS,3bS,9aR,9bS,11aS)-1-Acetyl-9a,11a-dimethyl-1,2,3,3a,3b,4,5,8,9,9a,9b,10,11,11a-tetradecahydro-7H-cyclopenta[a]phenanthren-7-one | |
Other names P4; [3] Pregnenedione | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.000.318 |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
C21H30O2 | |
Molar mass | 314.469 g/mol |
Density | 1.171 |
Melting point | 126 |
log P | 4.04 [4] |
Pharmacology | |
G03DA04 ( WHO ) | |
By mouth, topical/transdermal, vaginal, intramuscular injection, subcutaneous injection, subcutaneous implant | |
Pharmacokinetics: | |
OMP: <10% [5] [6] | |
• Albumin: 80% • CBG: 18% • SHBG: <1% • Free: 1–2% [7] [8] | |
Hepatic (CYP2C19, CYP3A4, CYP2C9, 5α-reductase, 3α-HSD , 17α-hydroxylase, 21-hydroxylase, 20α-HSD ) [9] [10] | |
OMP: 16–18 hours [5] [6] [11] IM: 22–26 hours [6] [12] SC: 13–18 hours [12] | |
Renal | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. [3] [13] It belongs to a group of steroid hormones called the progestogens [13] and is the major progestogen in the body. Progesterone has a variety of important functions in the body. It is also a crucial metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid. [14]
In addition to its role as a natural hormone, progesterone is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. [15] It was first prescribed in 1934. [16]
Progesterone is the most important progestogen in the body. As a potent agonist of the nuclear progesterone receptor (nPR) (with an affinity of KD = 1 nM) the resulting effects on ribosomal transcription plays a major role in regulation of female reproduction. [13] [17] In addition, progesterone is an agonist of the more recently discovered membrane progesterone receptors (mPRs), [18] of which the expression has regulation effects in reproduction function (oocyte maturation, labor, and sperm motility) and cancer although additional research is required to further define the roles. [19] It also functions as a ligand of the PGRMC1 (progesterone receptor membrane component 1) which impacts tumor progression, metabolic regulation, and viability control of nerve cells. [20] [21] [22] Moreover, progesterone is also known to be an antagonist of the sigma σ1 receptor, [23] [24] a negative allosteric modulator of nicotinic acetylcholine receptors, [14] and a potent antagonist of the mineralocorticoid receptor (MR). [25] Progesterone prevents MR activation by binding to this receptor with an affinity exceeding even those of aldosterone and glucocorticoids such as cortisol and corticosterone, [25] and produces antimineralocorticoid effects, such as natriuresis, at physiological concentrations. [26] In addition, progesterone binds to and behaves as a partial agonist of the glucocorticoid receptor (GR), albeit with very low potency (EC50 >100-fold less relative to cortisol). [27] [28]
Progesterone, through its neurosteroid active metabolites such as 5α-dihydroprogesterone and allopregnanolone, acts indirectly as a positive allosteric modulator of the GABAA receptor. [29]
Progesterone and some of its metabolites, such as 5β-dihydroprogesterone, are agonists of the pregnane X receptor (PXR), [30] albeit weakly so (EC50 >10 μM). [31] In accordance, progesterone induces several hepatic cytochrome P450 enzymes, [32] such as CYP3A4, [33] [34] especially during pregnancy when concentrations are much higher than usual. [35] Perimenopausal women have been found to have greater CYP3A4 activity relative to men and postmenopausal women, and it has been inferred that this may be due to the higher progesterone levels present in perimenopausal women. [33]
Progesterone modulates the activity of CatSper (cation channels of sperm) voltage-gated Ca2+ channels. Since eggs release progesterone, sperm may use progesterone as a homing signal to swim toward eggs (chemotaxis). As a result, it has been suggested that substances that block the progesterone binding site on CatSper channels could potentially be used in male contraception. [36] [37]
Progesterone has a number of physiological effects that are amplified in the presence of estrogens. Estrogens through estrogen receptors (ERs) induce or upregulate the expression of the PR. [39] One example of this is in breast tissue, where estrogens allow progesterone to mediate lobuloalveolar development. [40] [41] [42]
Elevated levels of progesterone potently reduce the sodium-retaining activity of aldosterone, resulting in natriuresis and a reduction in extracellular fluid volume. Progesterone withdrawal, on the other hand, is associated with a temporary increase in sodium retention (reduced natriuresis, with an increase in extracellular fluid volume) due to the compensatory increase in aldosterone production, which combats the blockade of the mineralocorticoid receptor by the previously elevated level of progesterone. [43]
Progesterone plays a role in early human sexual differentiation. [44] Placental progesterone is the feedstock for the 5α-dihydrotestosterone (DHT) produced via the backdoor pathway found operating in multiple non-gonadal tissues of the fetus, [45] whereas deficiencies in this pathway lead to undervirilization of the male fetus, resulting in incomplete development of the male genitalia. [46] [47] DHT is a potent androgen that is responsible for the development of male genitalia, including the penis and scrotum.
During early fetal development, the undifferentiated gonads can develop into either testes or ovaries. The presence of the Y chromosome leads to the development of testes. The testes then produce testosterone, which is converted to DHT via the enzyme 5α-reductase. DHT is a potent androgen that is responsible for the masculinization of the external genitalia and the development of the prostate gland. Progesterone, produced by the placenta during pregnancy, plays a role in fetal sexual differentiation by serving as a precursor molecule for the synthesis of DHT via the backdoor pathway. In the absence of adequate levels of steroidogenic enzymes during fetal development, the backdoor pathway for DHT synthesis can become deficient, leading to undermasculinization of the male fetus. This can result in the development of ambiguous genitalia or even female genitalia in some cases. Therefore, both DHT and progesterone play crucial roles in early fetal sexual differentiation, with progesterone acting as a precursor molecule for DHT synthesis and DHT promoting the development of male genitalia. [44]
Progesterone has key effects via non-genomic signalling on human sperm as they migrate through the female reproductive tract before fertilization occurs, though the receptor(s) as yet remain unidentified. [48] Detailed characterisation of the events occurring in sperm in response to progesterone has elucidated certain events including intracellular calcium transients and maintained changes, [49] slow calcium oscillations, [50] now thought to possibly regulate motility. [51] It is produced by the ovaries. [52] Progesterone has also been shown to demonstrate effects on octopus spermatozoa. [53]
Progesterone is sometimes called the "hormone of pregnancy", [54] and it has many roles relating to the development of the fetus:
The fetus metabolizes placental progesterone in the production of adrenal steroids. [45]
Progesterone plays an important role in breast development. In conjunction with prolactin, it mediates lobuloalveolar maturation of the mammary glands during pregnancy to allow for milk production and thus lactation and breastfeeding of offspring following parturition (childbirth). [58] Estrogen induces expression of the PR in breast tissue and hence progesterone is dependent on estrogen to mediate lobuloalveolar development. [40] [41] [42] It has been found that RANKL is a critical downstream mediator of progesterone-induced lobuloalveolar maturation. [59] RANKL knockout mice show an almost identical mammary phenotype to PR knockout mice, including normal mammary ductal development but complete failure of the development of lobuloalveolar structures. [59]
Though to a far lesser extent than estrogen, which is the major mediator of mammary ductal development (via the ERα), [60] [61] progesterone may be involved in ductal development of the mammary glands to some extent as well. [62] PR knockout mice or mice treated with the PR antagonist mifepristone show delayed although otherwise normal mammary ductal development at puberty. [62] In addition, mice modified to have overexpression of PRA display ductal hyperplasia, [59] and progesterone induces ductal growth in the mouse mammary gland. [62] Progesterone mediates ductal development mainly via induction of the expression of amphiregulin, the same growth factor that estrogen primarily induces the expression of to mediate ductal development. [62] These animal findings suggest that, while not essential for full mammary ductal development, progesterone seems to play a potentiating or accelerating role in estrogen-mediated mammary ductal development. [62]
Progesterone also appears to be involved in the pathophysiology of breast cancer, though its role, and whether it is a promoter or inhibitor of breast cancer risk, has not been fully elucidated. [63] [64] Most progestins, or synthetic progestogens, like medroxyprogesterone acetate, have been found to increase the risk of breast cancer in postmenopausal people in combination with estrogen as a component of menopausal hormone therapy. [65] [64] The combination of natural oral progesterone or the atypical progestin dydrogesterone with estrogen has been associated with less risk of breast cancer than progestins plus estrogen. [66] [67] [68] However, this may simply be an artifact of the low progesterone levels produced with oral progesterone. [63] [69] More research is needed on the role of progesterone in breast cancer. [64]
The estrogen receptor, as well as the progesterone receptor, have been detected in the skin, including in keratinocytes and fibroblasts. [70] [71] At menopause and thereafter, decreased levels of female sex hormones result in atrophy, thinning, and increased wrinkling of the skin and a reduction in skin elasticity, firmness, and strength. [70] [71] These skin changes constitute an acceleration in skin aging and are the result of decreased collagen content, irregularities in the morphology of epidermal skin cells, decreased ground substance between skin fibers, and reduced capillaries and blood flow. [70] [71] The skin also becomes more dry during menopause, which is due to reduced skin hydration and surface lipids (sebum production). [70] Along with chronological aging and photoaging, estrogen deficiency in menopause is one of the three main factors that predominantly influences skin aging. [70]
Hormone replacement therapy, consisting of systemic treatment with estrogen alone or in combination with a progestogen, has well-documented and considerable beneficial effects on the skin of postmenopausal people. [70] [71] These benefits include increased skin collagen content, skin thickness and elasticity, and skin hydration and surface lipids. [70] [71] Topical estrogen has been found to have similar beneficial effects on the skin. [70] In addition, a study has found that topical 2% progesterone cream significantly increases skin elasticity and firmness and observably decreases wrinkles in peri- and postmenopausal people. [71] Skin hydration and surface lipids, on the other hand, did not significantly change with topical progesterone. [71]
These findings suggest that progesterone, like estrogen, also has beneficial effects on the skin, and may be independently protective against skin aging. [71]
Progesterone and its neurosteroid active metabolite allopregnanolone appear to be importantly involved in libido in females. [72]
Dr. Diana Fleischman, of the University of Portsmouth, and colleagues looked for a relationship between progesterone and sexual attitudes in 92 women. Their research, published in the Archives of Sexual Behavior found that women who had higher levels of progesterone scored higher on a questionnaire measuring homoerotic motivation. They also found that men who had high levels of progesterone were more likely to have higher homoerotic motivation scores after affiliative priming compared to men with low levels of progesterone. [73] [74] [75] [76]
Progesterone, like pregnenolone and dehydroepiandrosterone (DHEA), belongs to an important group of endogenous steroids called neurosteroids. It can be metabolized within all parts of the central nervous system. [77]
Neurosteroids are neuromodulators, and are neuroprotective, neurogenic, and regulate neurotransmission and myelination. [78] The effects of progesterone as a neurosteroid are mediated predominantly through its interactions with non-nuclear PRs, namely the mPRs and PGRMC1, as well as certain other receptors, such as the σ1 and nACh receptors. [79]
Previous studies have shown that progesterone supports the normal development of neurons in the brain, and that the hormone has a protective effect on damaged brain tissue. It has been observed in animal models that females have reduced susceptibility to traumatic brain injury and this protective effect has been hypothesized to be caused by increased circulating levels of estrogen and progesterone in females. [80]
The mechanism of progesterone protective effects may be the reduction of inflammation that follows brain trauma and hemorrhage. [81] [82]
Damage incurred by traumatic brain injury is believed to be caused in part by mass depolarization leading to excitotoxicity. One way in which progesterone helps to alleviate some of this excitotoxicity is by blocking the voltage-dependent calcium channels that trigger neurotransmitter release. [83] It does so by manipulating the signaling pathways of transcription factors involved in this release. Another method for reducing the excitotoxicity is by up-regulating the GABAA, a widespread inhibitory neurotransmitter receptor. [84]
Progesterone has also been shown to prevent apoptosis in neurons, a common consequence of brain injury. [85] It does so by inhibiting enzymes involved in the apoptosis pathway specifically concerning the mitochondria, such as activated caspase 3 and cytochrome c.
Not only does progesterone help prevent further damage, it has also been shown to aid in neuroregeneration. [86] One of the serious effects of traumatic brain injury includes edema. Animal studies show that progesterone treatment leads to a decrease in edema levels by increasing the concentration of macrophages and microglia sent to the injured tissue. [83] [87] This was observed in the form of reduced leakage from the blood brain barrier in secondary recovery in progesterone treated rats. In addition, progesterone was observed to have antioxidant properties, reducing the concentration of oxygen free radicals faster than without. [84] There is also evidence that the addition of progesterone can also help remyelinate damaged axons due to trauma, restoring some lost neural signal conduction. [84] Another way progesterone aids in regeneration includes increasing the circulation of endothelial progenitor cells in the brain. [88] This helps new vasculature to grow around scar tissue which helps repair the area of insult.
Progesterone enhances the function of serotonin receptors in the brain, so an excess or deficit of progesterone has the potential to result in significant neurochemical issues. This provides an explanation for why some people resort to substances that enhance serotonin activity such as nicotine, alcohol, and cannabis when their progesterone levels fall below optimal levels. [89]
In a 2012 University of Amsterdam study of 120 women, women's luteal phase (higher levels of progesterone, and increasing levels of estrogen) was correlated with a lower level of competitive behavior in gambling and math contest scenarios, while their premenstrual phase (sharply-decreasing levels of progesterone, and decreasing levels of estrogen) was correlated with a higher level of competitive behavior. [92]
In mammals, progesterone, like all other steroid hormones, is synthesized from pregnenolone, which itself is derived from cholesterol.
Cholesterol undergoes double oxidation to produce 22R-hydroxycholesterol and then 20α,22R-dihydroxycholesterol. This vicinal diol is then further oxidized with loss of the side chain starting at position C22 to produce pregnenolone. This reaction is catalyzed by cytochrome P450scc.
The conversion of pregnenolone to progesterone takes place in two steps. First, the 3β-hydroxyl group is oxidized to a keto group and second, the double bond is moved to C4, from C5 through a keto/enol tautomerization reaction. [108] This reaction is catalyzed by 3β-hydroxysteroid dehydrogenase/δ5-4-isomerase.
Progesterone in turn is the precursor of the mineralocorticoid aldosterone, and after conversion to 17α-hydroxyprogesterone, of cortisol and androstenedione. Androstenedione can be converted to testosterone, estrone, and estradiol, highlighting the critical role of progesterone in testosterone synthesis.
Pregnenolone and progesterone can also be synthesized by yeast. [109]
Approximately 25 mg of progesterone is secreted from the ovaries per day, while the adrenal glands produce about 2 mg of progesterone per day. [110]
Sex | Sex hormone | Reproductive phase | Blood production rate | Gonadal secretion rate | Metabolic clearance rate | Reference range (serum levels) | |
---|---|---|---|---|---|---|---|
SI units | Non-SI units | ||||||
Men | Androstenedione | – | 2.8 mg/day | 1.6 mg/day | 2200 L/day | 2.8–7.3 nmol/L | 80–210 ng/dL |
Testosterone | – | 6.5 mg/day | 6.2 mg/day | 950 L/day | 6.9–34.7 nmol/L | 200–1000 ng/dL | |
Estrone | – | 150 μg/day | 110 μg/day | 2050 L/day | 37–250 pmol/L | 10–70 pg/mL | |
Estradiol | – | 60 μg/day | 50 μg/day | 1600 L/day | <37–210 pmol/L | 10–57 pg/mL | |
Estrone sulfate | – | 80 μg/day | Insignificant | 167 L/day | 600–2500 pmol/L | 200–900 pg/mL | |
Women | Androstenedione | – | 3.2 mg/day | 2.8 mg/day | 2000 L/day | 3.1–12.2 nmol/L | 89–350 ng/dL |
Testosterone | – | 190 μg/day | 60 μg/day | 500 L/day | 0.7–2.8 nmol/L | 20–81 ng/dL | |
Estrone | Follicular phase | 110 μg/day | 80 μg/day | 2200 L/day | 110–400 pmol/L | 30–110 pg/mL | |
Luteal phase | 260 μg/day | 150 μg/day | 2200 L/day | 310–660 pmol/L | 80–180 pg/mL | ||
Postmenopause | 40 μg/day | Insignificant | 1610 L/day | 22–230 pmol/L | 6–60 pg/mL | ||
Estradiol | Follicular phase | 90 μg/day | 80 μg/day | 1200 L/day | <37–360 pmol/L | 10–98 pg/mL | |
Luteal phase | 250 μg/day | 240 μg/day | 1200 L/day | 699–1250 pmol/L | 190–341 pg/mL | ||
Postmenopause | 6 μg/day | Insignificant | 910 L/day | <37–140 pmol/L | 10–38 pg/mL | ||
Estrone sulfate | Follicular phase | 100 μg/day | Insignificant | 146 L/day | 700–3600 pmol/L | 250–1300 pg/mL | |
Luteal phase | 180 μg/day | Insignificant | 146 L/day | 1100–7300 pmol/L | 400–2600 pg/mL | ||
Progesterone | Follicular phase | 2 mg/day | 1.7 mg/day | 2100 L/day | 0.3–3 nmol/L | 0.1–0.9 ng/mL | |
Luteal phase | 25 mg/day | 24 mg/day | 2100 L/day | 19–45 nmol/L | 6–14 ng/mL | ||
Notes and sources Notes: "The concentration of a steroid in the circulation is determined by the rate at which it is secreted from glands, the rate of metabolism of precursor or prehormones into the steroid, and the rate at which it is extracted by tissues and metabolized. The secretion rate of a steroid refers to the total secretion of the compound from a gland per unit time. Secretion rates have been assessed by sampling the venous effluent from a gland over time and subtracting out the arterial and peripheral venous hormone concentration. The metabolic clearance rate of a steroid is defined as the volume of blood that has been completely cleared of the hormone per unit time. The production rate of a steroid hormone refers to entry into the blood of the compound from all possible sources, including secretion from glands and conversion of prohormones into the steroid of interest. At steady state, the amount of hormone entering the blood from all sources will be equal to the rate at which it is being cleared (metabolic clearance rate) multiplied by blood concentration (production rate = metabolic clearance rate × concentration). If there is little contribution of prohormone metabolism to the circulating pool of steroid, then the production rate will approximate the secretion rate." Sources: See template. |
Progesterone binds extensively to plasma proteins, including albumin (50–54%) and transcortin (43–48%). [111] It has similar affinity for albumin relative to the PR. [17]
The metabolism of progesterone is rapid and extensive and occurs mainly in the liver, [112] [113] [114] though enzymes that metabolize progesterone are also expressed widely in the brain, skin, and various other extrahepatic tissues. [77] [115] Progesterone has an elimination half-life of only approximately 5 minutes in circulation. [112] The metabolism of progesterone is complex, and it may form as many as 35 different unconjugated metabolites when it is ingested orally. [114] [116] Progesterone is highly susceptible to enzymatic reduction via reductases and hydroxysteroid dehydrogenases due to its double bond (between the C4 and C5 positions) and its two ketones (at the C3 and C20 positions). [114]
The major metabolic pathway of progesterone is reduction by 5α-reductase [77] and 5β-reductase into the dihydrogenated 5α-dihydroprogesterone and 5β-dihydroprogesterone, respectively. [113] [114] [117] [118] This is followed by the further reduction of these metabolites via 3α-hydroxysteroid dehydrogenase and 3β-hydroxysteroid dehydrogenase into the tetrahydrogenated allopregnanolone, pregnanolone, isopregnanolone, and epipregnanolone. [119] [113] [114] [117] Subsequently, 20α-hydroxysteroid dehydrogenase and 20β-hydroxysteroid dehydrogenase reduce these metabolites to form the corresponding hexahydrogenated pregnanediols (eight different isomers in total), [113] [118] which are then conjugated via glucuronidation and/or sulfation, released from the liver into circulation, and excreted by the kidneys into the urine. [112] [114] The major metabolite of progesterone in the urine is the 3α,5β,20α isomer of pregnanediol glucuronide, which has been found to constitute 15 to 30% of an injection of progesterone. [17] [120] Other metabolites of progesterone formed by the enzymes in this pathway include 3α-dihydroprogesterone, 3β-dihydroprogesterone, 20α-dihydroprogesterone, and 20β-dihydroprogesterone, as well as various combination products of the enzymes aside from those already mentioned. [17] [114] [120] [121] Progesterone can also first be hydroxylated (see below) and then reduced. [114] Endogenous progesterone is metabolized approximately 50% into 5α-dihydroprogesterone in the corpus luteum, 35% into 3β-dihydroprogesterone in the liver, and 10% into 20α-dihydroprogesterone. [122]
Relatively small portions of progesterone are hydroxylated via 17α-hydroxylase (CYP17A1) and 21-hydroxylase (CYP21A2) into 17α-hydroxyprogesterone and 11-deoxycorticosterone (21-hydroxyprogesterone), respectively, [116] and pregnanetriols are formed secondarily to 17α-hydroxylation. [123] [124] Even smaller amounts of progesterone may be also hydroxylated via 11β-hydroxylase (CYP11B1) and to a lesser extent via aldosterone synthase (CYP11B2) into 11β-hydroxyprogesterone. [125] [126] [44] In addition, progesterone can be hydroxylated in the liver by other cytochrome P450 enzymes which are not steroid-specific. [127] 6β-Hydroxylation, which is catalyzed mainly by CYP3A4, is the major transformation, and is responsible for approximately 70% of cytochrome P450-mediated progesterone metabolism. [127] Other routes include 6α-, 16α-, and 16β-hydroxylation. [114] However, treatment of women with ketoconazole, a strong CYP3A4 inhibitor, had minimal effects on progesterone levels, producing only a slight and non-significant increase, and this suggests that cytochrome P450 enzymes play only a small role in progesterone metabolism. [128]
Metabolism of progesterone in humans [129] |
Progesterone levels are relatively low during the preovulatory phase of the menstrual cycle, rise after ovulation, and are elevated during the luteal phase, as shown in the diagram above. Progesterone levels tend to be less than 2 ng/mL prior to ovulation and greater than 5 ng/mL after ovulation. If pregnancy occurs, human chorionic gonadotropin is released, maintaining the corpus luteum and allowing it to maintain levels of progesterone. Between 7 and 9 weeks, the placenta begins to produce progesterone in place of the corpus luteum in a process called the luteal-placental shift. [131]
After the luteal-placental shift, progesterone levels start to rise further and may reach 100 to 200 ng/mL at term. Whether a decrease in progesterone levels is critical for the initiation of labor has been argued and may be species-specific. After delivery of the placenta and during lactation, progesterone levels are very low.
Progesterone levels are low in children and postmenopausal people. [132] Adult males have levels similar to those in women during the follicular phase of the menstrual cycle.
Group | P4 production | P4 levels | ||
---|---|---|---|---|
Prepubertal children | ND | 0.06–0.5 ng/mL | ||
Pubertal girls Tanner stage I (childhood) Tanner stage II (ages 8–12) Tanner stage III (ages 10–13) Tanner stage IV (ages 11–14) Tanner stage V (ages 12–15) Follicular phase (days 1–14) Luteal phase (days 15–28) | ND ND ND ND ND ND | 0.22 (<0.10–0.32) ng/mL 0.30 (0.10–0.51) ng/mL 0.36 (0.10–0.75) ng/mL 1.75 (<0.10–25.0) ng/mL 0.35 (0.13–0.75) ng/mL 2.0–25.0 ng/mL | ||
Premenopausal women Follicular phase (days 1–14) Luteal phase (days 15–28) Oral contraceptive (anovulatory) | 0.75–5.4 mg/day 15–50 mg/day ND | 0.02–1.2 ng/mL 4–30 ng/mL 0.1–0.3 ng/mL | ||
Postmenopausal women Oophorectomized women Oophorectomized and adrenalectomized women | ND 1.2 mg/day <0.3 mg/day | 0.03–0.3 ng/mL 0.39 ng/mL ND | ||
Pregnant women First trimester (weeks 1–12) Second trimester (weeks 13–26) Third trimester (weeks 27–40) Postpartum (at 24 hours) | 55 mg/day 92–100 mg/day 190–563 mg/day ND | 9–75 ng/mL 17–146 ng/mL 55–255 ng/mL 19 ng/mL | ||
Men | 0.75–3 mg/day | 0.1–0.3 ng/mL | ||
Notes: Mean levels are given as a single value and ranges are given after in parentheses. Sources: [129] [133] [134] [135] [136] [137] [138] [139] [140] |
Blood test results should always be interpreted using the reference ranges provided by the laboratory that performed the results. Example reference ranges are listed below.
Person type | Reference range for blood test | ||
---|---|---|---|
Lower limit | Upper limit | Unit | |
Female - menstrual cycle | (see diagram below) | ||
Female - postmenopausal | <0.2 [141] | 1 [141] | ng/mL |
<0.6 [142] | 3 [142] | nmol/L | |
Female on oral contraceptives | 0.34 [141] | 0.92 [141] | ng/mL |
1.1 [142] | 2.9 [142] | nmol/L | |
Males ≥16 years | 0.27 [141] | 0.9 [141] | ng/mL |
0.86 [142] | 2.9 [142] | nmol/L | |
Female or male 1–9 years | 0.1 [141] | 4.1 [141] or 4.5 [141] | ng/mL |
0.3 [142] | 13 [142] | nmol/L |
Progesterone is produced in high amounts in the ovaries (by the corpus luteum) from the onset of puberty to menopause, and is also produced in smaller amounts by the adrenal glands after the onset of adrenarche in both males and females. To a lesser extent, progesterone is produced in nervous tissue, especially in the brain, and in adipose (fat) tissue, as well.
During human pregnancy, progesterone is produced in increasingly high amounts by the ovaries and placenta. At first, the source is the corpus luteum that has been "rescued" by the presence of human chorionic gonadotropin (hCG) from the conceptus. However, after the 8th week, production of progesterone shifts to the placenta. The placenta utilizes maternal cholesterol as the initial substrate, and most of the produced progesterone enters the maternal circulation, but some is picked up by the fetal circulation and used as substrate for fetal corticosteroids. At term the placenta produces about 250 mg progesterone per day.
An additional animal source of progesterone is milk products. After consumption of milk products the level of bioavailable progesterone goes up. [144]
In at least one plant, Juglans regia , progesterone has been detected. [145] In addition, progesterone-like steroids are found in Dioscorea mexicana . Dioscorea mexicana is a plant that is part of the yam family native to Mexico. [146] It contains a steroid called diosgenin that is taken from the plant and is converted into progesterone. [147] Diosgenin and progesterone are also found in other Dioscorea species, as well as in other plants that are not closely related, such as fenugreek.
Another plant that contains substances readily convertible to progesterone is Dioscorea pseudojaponica native to Taiwan. Research has shown that the Taiwanese yam contains saponins — steroids that can be converted to diosgenin and thence to progesterone. [148]
Many other Dioscorea species of the yam family contain steroidal substances from which progesterone can be produced. Among the more notable of these are Dioscorea villosa and Dioscorea polygonoides . One study showed that the Dioscorea villosa contains 3.5% diosgenin. [149] Dioscorea polygonoides has been found to contain 2.64% diosgenin as shown by gas chromatography-mass spectrometry. [150] Many of the Dioscorea species that originate from the yam family grow in countries that have tropical and subtropical climates. [151]
Progesterone is used as a medication. It is used in combination with estrogens mainly in hormone therapy for menopausal symptoms and low sex hormone levels. [116] [152] It may also be used alone to treat menopausal symptoms. Studies have shown that transdermal progesterone (skin patch) and oral micronized progesterone are effective treatments for certain symptoms of menopause such as hot flashes and night sweats, which are otherwise referred to as vasomotor symptoms or VMS. [153]
It is also used to support pregnancy and fertility and to treat gynecological disorders. [154] [155] [156] [157] Progesterone has been shown to prevent miscarriage in those with 1) vaginal bleeding early in their current pregnancy and 2) a previous history of miscarriage. [158] Progesterone can be taken by mouth, through the vagina, and by injection into muscle or fat, among other routes. [116]
Progesterone is a naturally occurring pregnane steroid and is also known as pregn-4-ene-3,20-dione. [159] [160] It has a double bond (4-ene) between the C4 and C5 positions and two ketone groups (3,20-dione), one at the C3 position and the other at the C20 position. [159] [160]
Progesterone is commercially produced by semisynthesis. Two main routes are used: one from yam diosgenin first pioneered by Marker in 1940, and one based on soy phytosterols scaled up in the 1970s. Additional (not necessarily economical) semisyntheses of progesterone have also been reported starting from a variety of steroids. For the example, cortisone can be simultaneously deoxygenated at the C-17 and C-21 position by treatment with iodotrimethylsilane in chloroform to produce 11-keto-progesterone (ketogestin), which in turn can be reduced at position-11 to yield progesterone. [161]
An economical semisynthesis of progesterone from the plant steroid diosgenin isolated from yams was developed by Russell Marker in 1940 for the Parke-Davis pharmaceutical company. [162] This synthesis is known as the Marker degradation.
The 16-DPA intermediate is important to the synthesis of many other medically important steroids. A very similar approach can produce 16-DPA from solanine. [163]
Progesterone can also be made from the stigmasterol found in soybean oil also. c.f. Percy Julian.
A total synthesis of progesterone was reported in 1971 by W.S. Johnson. [169] The synthesis begins with reacting the phosphonium salt 7 with phenyl lithium to produce the phosphonium ylide 8. The ylide 8 is reacted with an aldehyde to produce the alkene 9. The ketal protecting groups of 9 are hydrolyzed to produce the diketone 10, which in turn is cyclized to form the cyclopentenone 11. The ketone of 11 is reacted with methyl lithium to yield the tertiary alcohol 12, which in turn is treated with acid to produce the tertiary cation 13. The key step of the synthesis is the π-cation cyclization of 13 in which the B-, C-, and D-rings of the steroid are simultaneously formed to produce 14. This step resembles the cationic cyclization reaction used in the biosynthesis of steroids and hence is referred to as biomimetic. In the next step the enol orthoester is hydrolyzed to produce the ketone 15. The cyclopentene A-ring is then opened by oxidizing with ozone to produce 16. Finally, the diketone 17 undergoes an intramolecular aldol condensation by treating with aqueous potassium hydroxide to produce progesterone. [169]
George W. Corner and Willard M. Allen discovered the hormonal action of progesterone in 1929. [17] [170] [171] [172] By 1931–1932, nearly pure crystalline material of high progestational activity had been isolated from the corpus luteum of animals, and by 1934, pure crystalline progesterone had been refined and obtained and the chemical structure of progesterone was determined. [17] [171] This was achieved by Adolf Butenandt at the Chemisches Institut of Technical University in Danzig, who extracted this new compound from several thousand liters of urine. [173]
Chemical synthesis of progesterone from stigmasterol and pregnanediol was accomplished later that year. [171] [174] Up to this point, progesterone, known generically as corpus luteum hormone, had been being referred to by several groups by different names, including corporin, lutein, luteosterone, and progestin. [17] [175] In 1935, at the time of the Second International Conference on the Standardization of Sex Hormones in London, England, a compromise was made between the groups and the name progesterone (progestational steroidal ketone) was created. [17] [176]
The use of progesterone tests in dog breeding to pinpoint ovulation is becoming more widely used. There are several tests available but the most reliable test is a blood test with blood drawn by a veterinarian and sent to a lab for processing. Results can usually be obtained with 24 to 72 hours. The rationale for using progesterone tests is that increased numbers begin in close proximity to preovulatory surge in gonadotrophins and continue through ovulation and estrus. When progesterone levels reach certain levels they can signal the stage of estrus the female is. Prediction of birth date of the pending litter can be very accurate if ovulation date is known. Puppies deliver with a day or two of 9 weeks gestation in most cases. It is not possible to determine pregnancy using progesterone tests once a breeding has taken place, however. This is due to the fact that, in dogs, progesterone levels remain elevated throughout the estrus period. [177]
Pricing for progesterone can vary depending location, insurance coverage, discount coupons, quantity, shortages, manufacturers, brand or generic versions, different pharmacies, and so on. As of currently, 30 capsules of 100 mg of the generic version, Prometrium, from CVS Pharmacy is around $40 without any discounts or insurance applied. The brand version, Progesterone, is around $450 for 30 capsules without any discounts or insurance applied. [178] In comparison, Walgreens offers 30 capsules of 100 mg in the generic version for $51 without insurance or coupons applied. The brand name costs around $431 for 30 capsules of 100 mg. [179]
Estrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy.
Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many other tissues including bone, fat, skin, liver, and the brain.
Progestogens, also sometimes written progestins, progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy, although they are also present at other phases of the estrous and menstrual cycles.
A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural female sex hormone progesterone in the body. A progestin is a synthetic progestogen. Progestogens are used most commonly in hormonal birth control and menopausal hormone therapy. They can also be used in the treatment of gynecological conditions, to support fertility and pregnancy, to lower sex hormone levels for various purposes, and for other indications. Progestogens are used alone or in combination with estrogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of progestogens include natural or bioidentical progesterone as well as progestins such as medroxyprogesterone acetate and norethisterone.
Hot flashes, also known as hot flushes, are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, and may typically last from two to 30 minutes for each occurrence.
Drospirenone is a progestin and antiandrogen medication which is used in birth control pills to prevent pregnancy and in menopausal hormone therapy, among other uses. It is available both alone under the brand name Slynd and in combination with an estrogen under the brand name Yasmin among others. The medication is an analog of the drug spironolactone. Drospirenone is taken by mouth.
Tibolone, sold under the brand name Livial among others, is a medication which is used in menopausal hormone therapy and in the treatment of postmenopausal osteoporosis and endometriosis. The medication is available alone and is not formulated or used in combination with other medications. It is taken by mouth.
Dydrogesterone, sold under the brand name Duphaston among others, is a progestin medication which is used for a variety of indications, including threatened or recurrent miscarriage during pregnancy, dysfunctional bleeding, infertility due to luteal insufficiency, dysmenorrhea, endometriosis, secondary amenorrhea, irregular cycles, premenstrual syndrome, and as a component of menopausal hormone therapy. It is taken by mouth.
Feminizing hormone therapy, also known as transfeminine hormone therapy, is hormone therapy and sex reassignment therapy to change the secondary sex characteristics of transgender people from masculine or androgynous to feminine. It is a common type of transgender hormone therapy and is used to treat transgender women and non-binary transfeminine individuals. Some, in particular intersex people, but also some non-transgender people, take this form of therapy according to their personal needs and preferences.
5α-Dihydroprogesterone is an endogenous progestogen and neurosteroid that is synthesized from progesterone. It is also an intermediate in the synthesis of allopregnanolone and isopregnanolone from progesterone.
Estetrol (E4), or oestetrol, is one of the four natural estrogenic steroid hormones found in humans, along with estrone (E1), estradiol (E2), and estriol (E3). Estetrol is a major estrogen in the body. In contrast to estrone and estradiol, estetrol is a native estrogen of fetal life. Estetrol is produced exclusively by the fetal liver and is found in detectable levels only during pregnancy, with relatively high levels in the fetus and lower levels in the maternal circulation.
Trimegestone, sold under the brand names Ondeva and Totelle among others, is a progestin medication which is used in menopausal hormone therapy and in the prevention of postmenopausal osteoporosis. It was also under development for use in birth control pills to prevent pregnancy, but ultimately was not marketed for this purpose. The medication is available alone or in combination with an estrogen. It is taken by mouth.
Nomegestrol acetate (NOMAC), sold under the brand names Lutenyl and Zoely among others, is a progestin medication which is used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. It is available both alone and in combination with an estrogen. NOMAC is taken by mouth. A birth control implant for placement under the skin was also developed but ultimately was not marketed.
A neurosteroidogenesis inhibitor is a drug that inhibits the production of endogenous neurosteroids. Neurosteroids include the excitatory neurosteroids pregnenolone sulfate, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S), and the inhibitory neurosteroids allopregnanolone, tetrahydrodeoxycorticosterone (THDOC), and 3α-androstanediol, among others. By inhibiting the synthesis of endogenous neurosteroids, neurosteroidogenesis inhibitors have effects in the central nervous system.
20α-Dihydroprogesterone (20α-DHP), also known as 20α-hydroxyprogesterone (20α-OHP), is a naturally occurring, endogenous progestogen. It is a metabolite of progesterone, formed by the 20α-hydroxysteroid dehydrogenases (20α-HSDs) AKR1C1, AKR1C2, and AKR1C3 and the 17β-hydroxysteroid dehydrogenase (17β-HSD) HSD17B1. 20α-DHP can be transformed back into progesterone by 20α-HSDs and by the 17β-HSD HSD17B2. HSD17B2 is expressed in the human endometrium and cervix among other tissues. In animal studies, 20α-DHP has been found to be selectively taken up into and retained in target tissues such as the uterus, brain, and skeletal muscle.
5β-Dihydroprogesterone is an endogenous neurosteroid and an intermediate in the biosynthesis of pregnanolone and epipregnanolone from progesterone. It is synthesized from progesterone by the enzyme 5β-reductase.
Estradiol (E2) is a medication and naturally occurring steroid hormone. It is an estrogen and is used mainly in menopausal hormone therapy and to treat low sex hormone levels in women. It is also used in hormonal birth control for women, in feminizing hormone therapy for transgender women and some non-binary individuals, and in the treatment of hormone-sensitive cancers like prostate cancer in men and breast cancer in women, among other uses. Estradiol can be taken by mouth, held and dissolved under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes.
Progesterone (P4), sold under the brand name Prometrium among others, is a medication and naturally occurring steroid hormone. It is a progestogen and is used in combination with estrogens mainly in hormone therapy for menopausal symptoms and low sex hormone levels in women. It is also used in women to support pregnancy and fertility and to treat gynecological disorders. Progesterone can be taken by mouth, vaginally, and by injection into muscle or fat, among other routes. A progesterone vaginal ring and progesterone intrauterine device used for birth control also exist in some areas of the world.
The pharmacology of progesterone, a progestogen medication and naturally occurring steroid hormone, concerns its pharmacodynamics, pharmacokinetics, and various routes of administration.
The pharmacokinetics of progesterone, concerns the pharmacodynamics, pharmacokinetics, and various routes of administration of progesterone.
Evidence has accrued that normal progesterone (and ovulation), as well as physiological estradiol levels, is necessary during ciswomen's premenopausal menstrual cycles for current fertility and long-term health; transgender women may require progesterone therapy and similar potential physiological benefits