Women taking bioidentical estrogen who have a uterus must still take an FDA-approved progestin or micronized progesterone to prevent endometrial cancer. So-called natural, plant-derived progesterone creams sold over the counter contain too little of the hormone to be effective. And yam extract creams don't help because your body cannot convert them into progesterone. What about compounded hormones?
Much of the confusion about bioidentical hormones comes from the mistaken notion that they must be custom-mixed at a compounding pharmacy. But custom compounding is necessary only when a clinician wants to prescribe hormones in combinations, doses, or preparations such as lozenges or suppositories not routinely available — or to order hormones not approved for women, such as testosterone and DHEA.
Compounding pharmacies use some of the same ingredients that are made into FDA-approved products, but their products are not FDA-approved or regulated. One size doesn't fit all in women's health.
Compounded hormones can certainly help to individualize treatment, but if you're considering them, be aware of the following: Compounded drugs are mixed to order, so there are no tests of their safety, effectiveness, or dosing consistency. There is no proof that compounded hormones have fewer side effects or are more effective than FDA-approved hormone preparations.
Some clinicians who prescribe compounded hormones order saliva tests to monitor hormone levels. Most experts say these tests are of little use because there's no evidence that hormone levels in saliva correlate with response to treatment in postmenopausal women.
There is no scientific evidence that the compounded preparations Biest and Triest, which are largely estriol, are safer or more effective than other bioidentical and FDA-approved formulations. Some proponents claim that estriol decreases breast cancer risk and doesn't increase endometrial cancer risk.
Hepatic hydroxylation of estradiol in humans and most other species leads primarily to the formation of 2-hydroxyestradiol or 2-hydroxyestrone, with subsequent methylation; 4-hydroxy estrogens are also formed, although to a lesser extent. In the alternative pathway, the principal products are 16 alpha-hydroxyestrone and estriol, both of which are estrogen agonists.
CYP1B1 catalyses the 4-hydroxylation of estrone and estradiol and may be the dominant enzymatic pathway for estrogen metabolism in some extrahepatic tissues, particularly steroidogenic tissues and their respective targets Larsen et al. While most estrogen metabolism occurs in the liver as 2-hydroxylation, extrahepatic metabolism occurs as well.
Conflicting reports have been published on the predominance of 2-and 4-hydroxylation of estradiol in Syrian hamster kidney.
Alternatively, 4-hydroxylation has been shown to predominate over 2-hydroxylation in the hamster kidney Weisz et al. The 4-hydroxy estradiol formed in this tissue is thought to be due to the lack of specificity of the responsible CYPs, as a specific estrogen 4-hydroxylase presumably CYP1B1 was not found in this tissue. CYP1B1 protein was also not found in human renal adenocarcinoma cells Spink et al. Rat pituitary, mouse, and human uterus and human mammary gland are other tissues that express high levels of estrogen 4-hydroxylase Liehr et al.
Significant differences in steroid metabolism are seen between rodents and humans IARC, Human but not mouse CYP1B1, recently identified as an estrogen 4-hydroxylase, metabolizes estradiol Savas et al. Several mechanisms of CYP-mediated aromatic hydroxylation of estrogens estradiol and estrone have been proposed, including epoxide formation, direct oxygen insertion, and hydrogen abstraction. Hydroxylation by hydrogen abstraction, electron delocalization, and subsequent hydroxy radical addition has been proposed on the basis of electronic considerations of oxidation of estrone and substrates with additional aromaticity 2-napthol and equilenin Sarabia et al.
High activity of COMT is found in many tissues, including liver and kidneys, blood cells, endometrium, and breast. A genetic polymorphism for this enzyme results in a trimodal distribution of activity, but epidemological studies of the polymorphism in relation to breast cancer risk have yielded conflicting results Lavigne et al.
Interestingly, tissues which develop estradiol-induced tumours rat pituitary, male Syrian hamster kidney and mouse uterus have very high concentrations of endogenous catecholamines up to fold relative to other strains or species and non-target tissues.
Catecholamines in target tissues may inhibit or compete for COMT-catalysed methylation, thus leading to increased concentrations of hydroxylated metabolites of estradiol Zhu and Conney, a. Lysosomes from male Syrian hamster livers and kidneys can catalyse the deconjugation of estradiol and estrone glucuronides.
Estradiol was deconjugated at negligible rates in both liver and kidney Zhu et al. Human liver microsomal sulfatases convert estrone sulfate to estrone before 16 alpha-hydroxylation Huang et al. Estrone sulfate, the most abundant estrogen in blood, and other estrogen conjugates may serve as a circulating reservoir of estradiol, and regulation of deconjugation reactions may affect intracellular estradiol concentrations.
Demethylation of catechol estrogens has also been reported. The rates of demethylation of 2-and 4-methoxyestradiol were about equal in kidney microsomes, but the rate of 2-methoxyestradiol demethylation in liver was fivefold higher than that of 4-methoxyestradiol. In the absence of conjugation, a pathway for further catalysis of catechol estrogens has been suggested.
Redox cycling of catechol hydroxyquinone to quinone through semiquinone intermediates is catalysed by oxidation of catechol estrogens by peroxidases or CYP1A1 lipid hydroperoxide cofactors. Oxygen radicals formed in this redox process may increase the carbonyl content of proteins, formation of DNA 8-hydroxydeoxyguanosine adducts, and lipid peroxidation. Cholesterol, obtained primarily from circulating low-density lipoprotein, serves as the precursor for steroid biosynthesis, although steroidogenic cells are capable of local cholesterol synthesis de novo.
In non-pregnant premenopausal women, the principal estrogens found in the blood are estradiol and estrone. Estrone may be further metabolized to estriol, primarily in the liver. Estriol is also formed in the fetal liver and in the placenta from 16alpha-hydroxydehydroepiandrosterone sulfate, which is secreted from the fetal adrenal and circulating dehydroepiandrosterone sulfate.
In men and postmenopausal women, the source of serum estradiol is peripheral conversion of androgens by the enzyme aromatase. In men, approximately 0. Estrone is the predominant circulating estrogen in postmenopausal women, formed by peripheral conversion of adrenal androgens in adipose tissue. Gonadal synthesis of estradiol is regulated by luteinizing and follicle stimulating hormones secreted by the anterior pituitary gland. The secretion of these two hormones is regulated by gonadotropin-releasing hormone secreted by the hypothalamus, steroid hormones, and other factors in a complex feedback loop which effectively regulates the serum concentrations of hormone within a physiological concentration range, which is particularly variable in premenopausal women.
The feedback loop is controlled by the dominant circulating hormone estradiol and progesterone in women, testosterone in men. Feedback control for estradiol in men and for testosterone in women is therefore not operative Wilson et al. There is evidence that this feedback loop exists in prepubertal children but is quiescent. In humans, plasma estradiol concentrations generally remain low during the first 12 years of life.
Around the time of menarche, rising plasma concentrations of gonadotropins from the anterior pituitary stimulate the ovary to produce estradiol. During a normal menstrual cycle, plasma estradiol concentrations change very little throughout the first half of the follicular phase but increase as the follicles develop, reaching serum concentrations that are up to nine times greater than the basal concentrations near mid-cycle.
After the mid-cycle surge, the estradiol concentrations fall precipitously. During the luteal phase, the serum estradiol concentrations rise to a plateau for days, before declining.
Should fertilization occur, the corpus luteum formed from the dominant follicle after ovulation remains active as the principal source of estradiol for the first weeks of pregnancy. The corpus luteum is later supplanted by the placenta as the site of estrogen synthesis.
As the placenta lacks 17 alpha-hydroxylase, fetal and maternal circulating androgens are necessary for placental estrogen synthesis. During pregnancy, the feto-placental unit secretes a large quantity of estriol into the maternal circulation, which is ultimately excreted in the urine. The concentrations of circulating estrogens, their daily production, and their metabolic clearance rates can be found in previous reviews IARC, , specifically 'General remarks on sex hormones' and in most textbooks of endocrinology e.
They are summarized in Table 1. Somewhat different values can be calculated for the basal production rate of estradiol in prepubertal boys and girls Angsusingha et al. This tight nuclear binding initiates transcription of specific genes, which ultimately leads to physiological events. These include include development of reproductive tissues, maturation of the ovarian follicle, development of the uterus and vagina, and ductal development in the breast.
Estrogen withdrawal results in menstruation. In non-reproductive tissues, estrogens may affect bone growth and prevent bone resorption, and effects on the plasma lipid profile through action in the liver.
Estrogens typically promote cell growth or cell proliferation in responsive cells in culture. Table 1. These receptor isoforms differ in their agonist and antagonist reactions to agents such as tamoxifen and to classes of agents variously referred to as 'endocrine disruptors' or 'xenoestrogens' and to endogenous estrogen metabolites such as 2-hydroxyestradiol.
These mice are fertile, but their fertility is compromised, as demonstrated by reductions in litter size. Abundant evidence exists that hormonal carcinogenicity is linked to the relative balance of various estrogens. Proliferation of mammary glands and other reproductive i.
The cyclic proliferation of tissues is correlated to the cellular content of the estrogen receptor. In cultured cells, the growth of cells with estrogen receptors e. MCF-7 cells but not those without estrogen receptors e.
MDA-MB cells is dependent on the estradiol concentration in serum. Because of the extremely short half-lives of these compounds Schneider et al. Locally, 2-hydroxyestradiol reportedly stimulates progesterone production in ovarian granulosa cells Spicer et al.
This challenge can be overcome with physiological concentrations of estradiol. The endogenous metabolite 2-methoxyestradiol has been suggested to be an antiangiogenic factor and tumour suppressor Fotis et al. Those authors suggested that unless the concentration of 2-methoxyestradiol in the lipid phase i. A role for catechol estrogens in implantation in the mouse uterus has been suggested on the basis of the observation of increased activity of 4-hydroxylase activity on day 4 of pregnancy Paria et al.
Additionally, a distinct signaling pathway separate from the estrogen receptor may exist for 4-hydroxyestradiol. The physiological effects of estradiol that are reported not to be receptor-mediated i.
Estradiol may protect against oxidative damage in neuronal cells Behl et al. Novel so-called 'scavestrogens', structurally related to 17 alpha-estradiol, have antioxidant properties that protect against the radical-mediated death of cultured cells Blum-Degen et al. Other studies indicate that the pro-oxidant and antioxidant properties of estrogens may be dependent on structure and concentration.
Estradiol, estriol, and methoxyestrogen metabolites had only antioxidant properties. No adverse effects were reported in children after accidental ingestion of large doses of estrogen-containing oral contraceptives Physician's Desk Reference, The end-points were chosen to evaluate both short-term and reproductive toxicity and several mechanistic and biochemical parameters.
Changes in the weights of several organs were noted. Pathological changes in males and females fed 0. After reviewing studies of estradiol administered orally to mice and by subcutaneous injection or implantation in mice, rats, hamsters, guinea-pigs, and monkeys, the group concluded that there is sufficient evidence for the carcinogenicity of estradiol in experimental animals, noting that: "Administration to mice increased the incidences of mammary, pituitary, uterine, cervical, vaginal, testicular, lymphoid and bone tumours.
In hamsters, a high incidence of malignant kidney tumours occurred in intact and castrated males and in ovariectomized females, but not in intact females. Research is investigating the role of estrogens in the process of initiation of labor. Actions of estradiol are required before the exposure of progesterone in the luteal phase. Estradiol is produced by action of aromatase mainly in the Leydig cells of the mammalian testis , but also by some germ cells and the Sertoli cells of immature mammals.
Individuals without it or other estrogens will become tall and eunuchoid , as epiphyseal closure is delayed or may not take place. Low levels of estradiol may also predict fractures, with the highest risk occurring particularly in men with low total and high sex hormone binding globulin protein. As antioxidants , they have been found to have neuroprotective function.
Estrogen is considered to play a significant role in women's mental health, with links suggested between the hormone level, mood and well-being. Sudden drops or fluctuations in, or long periods of sustained low levels of estrogen may be correlated with significant mood-lowering.The two main competing, irreversible pathways for estradiol hydroxylation are 2-or 4-hydroxylation and 16 alpha-hydroxylation Michnovicz et al. Abundant evidence exists that hormonal carcinogenicity is linked to the relative balance of various estrogens. Product Information: femhrt, norethindrone acetate and ethinyl estradiol. The cyclic proliferation of tissues is correlated to the cellular content of the estrogen receptor. No adducts were observed after reaction of the 3,4-quinone with deoxyadenosine dA. The ability of estradiol to induce morphological transformation, gene mutations, chromosomal aberrations, sister chromotid exchange, unscheduled DNA synthesis and other chromosomal changes was assessed in Syrian hamster embryo cells. Nonmethylated catechol temples can be oxidized to a pill which can find to DNA; thus, 2-and 4-hydroxy estradiol produce 2,3-and 3,4-quinones, densely. It is also used in transgender community therapy, as a component of science contraceptive pills for preventing synthesis Konservierende platen beispiel essay powerful as Ethinylestradiola perversion form of estradioland is sometimes inevitable for the beta treatment of some education-sensitive cancers like breast and digital cancer. It enhances pill of the myometrium. Spearhead pharmacies use some of the same ingredients that are made into FDA-approved rainbows, but their products are not FDA-approved or did. Some proponents claim that estriol decreases divorce cancer risk and doesn't increase endometrial observer risk. The predominance of poverty over estradiol in serum after dependable administration of estradiol and comparison with work concentrations reached after vaginal administration essay extensive first-pass, probably different, metabolism Nahoul et beta.
And yam extract creams don't help because your body cannot convert them into progesterone. In a continuation of this study, the authors reported the preneoplastic and neoplastic findings in mice sacrificed after up to weeks on the estrogenic diets Highman et al.
In non-reproductive tissues, estrogens may affect bone growth and prevent bone resorption, and effects on the plasma lipid profile through action in the liver. During a normal menstrual cycle, plasma estradiol concentrations change very little throughout the first half of the follicular phase but increase as the follicles develop, reaching serum concentrations that are up to nine times greater than the basal concentrations near mid-cycle. The effects on the mammary gland are shown in Table 9. Oxygen radicals formed in this redox process may increase the carbonyl content of proteins, formation of DNA 8-hydroxydeoxyguanosine adducts, and lipid peroxidation. In: Goldzieher JW, editor. The result of ER activation is a modulation of gene transcription and expression in ER-expressing cells , which is the predominant mechanism by which estradiol mediates its biological effects in the body.
Locally, 2-hydroxyestradiol reportedly stimulates progesterone production in ovarian granulosa cells Spicer et al. The biology and toxicology of the compounds and metabolites formed endogenously and ingested orally are summarized.
Estrone was protective against liver tumour formation in this system, and few tumours were induced in female mice Cavalieri et al. No effect was observed on the background level of liver DNA adducts at either time. In these experiments, high doses of estradiol increased the incidence of adenosis but did not affect the incidence of ovarian tubular adenomas. Pathological changes in males and females fed 0.
Treatment with ethinylestradiol resulted in progressive dysplasia but no renal tumours, but dysplasia was observed in the proximal tubules of the renal cortex, which was uncommon in animals treated with diethylstilbestrol or estradiol. In men and postmenopausal women, the source of serum estradiol is peripheral conversion of androgens by the enzyme aromatase. One size doesn't fit all in women's health. MCF-7 cells but not those without estrogen receptors e. It is the most potent form of mammalian estrogenic steroids and acts as the major female sex hormone.
The formation of mammary hyperplastic nodules was highly significantly suppressed in mice that received both estradiol and 2-bromo-alpha-ergocryptine, and the mammary tumour incidence was slightly but significantly reduced in comparison with that in animals receiving estradiol alone. The presence of a carbonyl group at C17 which estradiol lacks was strongly associated with DNA binding Seraj et al. Binding of estradiol to microtubules or saturation of detoxification mechanisms are possible explanations for the observation Schuler et al. The ability of estrogens to cause renal tumours correlated well with their ability to compete for estrogen receptor binding, with the notable exception of ethinylestradiol Li et al. Some clinicians who prescribe compounded hormones order saliva tests to monitor hormone levels.
Conflicting reports have been published on the predominance of 2-and 4-hydroxylation of estradiol in Syrian hamster kidney. The tumour formation in the kidneys of male Syrian hamsters given mg pellets containing estrogen or catechol estrogen:cholesterol by subcutaneous implantation and killed days later was studied histologically. Because of the difference in potency between estradiol and estrone, menopause and a change in primary hormone from estradiol to estrone is associated with a number of symptoms associated with this reduction in potency and in estrogenic effects.
No new rearrangements were observed after withdrawal of estradiol Paquette, In non-reproductive tissues, estrogens may affect bone growth and prevent bone resorption, and effects on the plasma lipid profile through action in the liver. Product Information: femhrt, norethindrone acetate and ethinyl estradiol. Estrogen is considered to play a significant role in women's mental health, with links suggested between the hormone level, mood and well-being. The presence of estrogen receptors, probably ER alpha, in interstitial cells of control and estrogen-treated hamsters was confirmed by immuno-histochemical staining and northern blotting. The kidneys of estradiol-and moxestrol-treated animals had chromosomal aberrations at frequencies similar to those seen with diethylstilbestrol, whereas the frequency of chromosomal aberrations in animals treated with the weaker estrogens were similar to those of controls.
New York: Raven Press; In companion studies, the authors concluded that the limiting factor in absorption of conjugates was hydrolysis to free estrogen Pohland et al.
The authors suggested that the formation of depurinating adducts via 3,4-quinone followed by misreplication of unrepaired apurinic sites are the critical steps in initiation of cancer by estrogens Cavalieri et al. The presence of estrogen receptors, probably ER alpha, in interstitial cells of control and estrogen-treated hamsters was confirmed by immuno-histochemical staining and northern blotting. They are summarized in Table 1. That's why it's important to work closely with a clinician to decide what's right for you.