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2D Structure
Also known as: 53-16-7, Folliculin, Oestrone, Theelin, Follicular hormone, Thelykinin
Molecular Formula
C18H22O2
Molecular Weight
270.4  g/mol
InChI Key
DNXHEGUUPJUMQT-CBZIJGRNSA-N
FDA UNII
X9XKA379T9

An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
(8R,9S,13S,14S)-3-hydroxy-13-methyl-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-17-one
2.1.2 InChI
InChI=1S/C18H22O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h3,5,10,14-16,19H,2,4,6-9H2,1H3/t14-,15-,16+,18+/m1/s1
2.1.3 InChI Key
DNXHEGUUPJUMQT-CBZIJGRNSA-N
2.1.4 Canonical SMILES
CC12CCC3C(C1CCC2=O)CCC4=C3C=CC(=C4)O
2.1.5 Isomeric SMILES
C[C@]12CC[C@H]3[C@H]([C@@H]1CCC2=O)CCC4=C3C=CC(=C4)O
2.2 Other Identifiers
2.2.1 UNII
X9XKA379T9
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Estrone, (+-)-isomer

2. Estrone, (8 Alpha)-isomer

3. Estrone, (9 Beta)-isomer

4. Estrovarin

5. Folliculin (hormone)

6. Kestrone

7. Unigen

8. Wehgen

2.3.2 Depositor-Supplied Synonyms

1. 53-16-7

2. Folliculin

3. Oestrone

4. Theelin

5. Follicular Hormone

6. Thelykinin

7. Ketohydroxyestrin

8. Estrovarin

9. Estrugenone

10. Femidyn

11. Kestrone

12. Tokokin

13. Estron

14. Follicunodis

15. Aquacrine

16. Disynformon

17. Folliculine

18. Glandubolin

19. Hiestrone

20. Hormestrin

21. Oestroform

22. Oestronum

23. Oestroperos

24. Folipex

25. Folisan

26. Kolpon

27. Menagen

28. Unden

29. Estrone-a

30. Ketohydroxyoestrin

31. 3-hydroxyestra-1,3,5(10)-trien-17-one

32. 1,3,5(10)-estratrien-3-ol-17-one

33. Estrona [spanish]

34. Folliculine Benzoate

35. Estrogenic Substance

36. Ovex (tablets)

37. Estronum [inn-latin]

38. Estrol

39. Estrona [inn-spanish]

40. Destrone

41. Oestrin

42. Endofolliculina

43. Estra-1,3,5(10)-trien-17-one, 3-hydroxy-

44. Crinovaryl

45. Cristallovar

46. Crystogen

47. Estrusol

48. Folikrin

49. Follestrine

50. Follestrol

51. Hormofollin

52. Hormovarine

53. Ketodestrin

54. Menformon

55. Mestronaq

56. Ovifollin

57. Perlatan

58. Solliculin

59. Thelestrin

60. Thynestron

61. Wynestron

62. (+)-estrone

63. Ketohydroxy-estratriene

64. 3-hydroxy-17-keto-estra-1,3,5-triene

65. Femestrone Injection

66. 3-hydroxyestra-1,3,5(10)-triene-17-one

67. 3-hydroxy-oestra-1,3,5(10)-trien-17-one

68. 1,3,5(10)-oestratrien-3-ol-17-one

69. 3-hydroxy-17-keto-oestra-1,3,5-triene

70. Delta-1,3,5-estratrien-3beta-ol-17-one

71. Fem-o-gen

72. (+/-)-oestrone

73. Delta-1,3,5-estratrien-3-beta-ol-17-one

74. Delta-1,3,5-oestratrien-3beta-ol-17-one

75. Delta-1,3,5-oestratrien-3-beta-ol-17-one

76. Folliculinum

77. (+/-)-estrone

78. Estrone Dl-form [mi]

79. Estrone, (+/-)-

80. Follicular-hormone

81. 3-hydroxy-1,3,5(10)-estratrien-17-one

82. (8r,9s,13s,14s)-3-hydroxy-13-methyl-7,8,9,11,12,14,15,16-octahydro-6h-cyclopenta[a]phenanthren-17-one

83. 19973-76-3

84. E(sub 1)

85. Estradiol Metabolite E1

86. 1,3,5-estratrien-3-ol-17-one

87. 3-hydroxy-estra-1,3,5(10)-trien-17-one

88. Chembl1405

89. Mls000028475

90. 2di9ha706a

91. X9xka379t9

92. Chebi:17263

93. Nsc-9699

94. Way 164397

95. Estra-1,3,5(10)-trien-17-one, 3-hydroxy-, (+/-)-

96. Estronum

97. Smr000058338

98. Dsstox_cid_2367

99. Dsstox_rid_76560

100. Dsstox_gsid_22367

101. (13s)-3-hydroxy-13-methyl-7,8,9,11,12,13,15,16-octahydro-6h-cyclopenta[a]phenanthren-17(14h)-one

102. [2,4,6,7-3h]-e1

103. Estrone (e1)

104. Hydroxyestrones

105. Unden (pharmaceutical) (van)

106. (9beta,13alpha)-3-hydroxyestra-1,3,5(10)-trien-17-one

107. Oestrone [steroidal Oestrogens]

108. (1s,10r,11s,15s)-5-hydroxy-15-methyltetracyclo[8.7.0.0^{2,7}.0^{11,15}]heptadeca-2(7),3,5-trien-14-one

109. (8r,9s,13s,14s)-3-hydroxy-13-methyl-6,7,8,9,11,12,13,14,15,16-decahydro-17h-cyclopenta[a]phenanthren-17-one

110. Ccris 285

111. Estrone (tn)

112. Hsdb 3324

113. Natural Estrogenic Substance-estrone

114. Nsc 9699

115. Einecs 200-164-5

116. Estrone (jan/usp/inn)

117. Estrone [usp:inn:ban]

118. Brn 1915077

119. Unii-2di9ha706a

120. Unii-x9xka379t9

121. Aquest

122. Cas-53-16-7

123. Ncgc00015423-03

124. (8r,9s,13s,14s)-3-hydroxy-13-methyl-6,7,8,9,11,12,13,14,15,16-decahydro-17h-cyclopenta(a)phenanthren-17-one

125. J3z

126. Cmc_13458

127. Estrone [vandf]

128. Opera_id_330

129. Estrone [hsdb]

130. Estrone, >=99%

131. Estrone [inn]

132. Estrone [jan]

133. Estrone [mi]

134. Estrone [mart.]

135. Prestwick0_000914

136. Prestwick1_000914

137. Prestwick2_000914

138. Prestwick3_000914

139. Spectrum5_002047

140. E0026

141. Estrone [usp-rs]

142. Estrone [who-dd]

143. Bmse000549

144. E 9750

145. Ec 200-164-5

146. Folliculinum [hpus]

147. Lopac0_000513

148. Schembl21702

149. Bspbio_000788

150. 3-08-00-01171 (beilstein Handbook Reference)

151. Mls001077340

152. Mls002695951

153. Mls006011890

154. Bidd:er0145

155. Estrone [orange Book]

156. Spbio_002977

157. Bpbio1_000868

158. Gtpl2818

159. Megxm0_000444

160. Sgcut00128

161. Estrone [usp Monograph]

162. Dtxsid4022367

163. Estrone 1.0 Mg/ml In Methanol

164. Acon0_000083

165. Acon1_000122

166. Bdbm17289

167. [2,4,6,7-3h]-estrone

168. Hms1570h10

169. Hms2090e22

170. Hms2097h10

171. Hms2232o15

172. Hms3261h07

173. Hms3714h10

174. Act02603

175. Bcp13336

176. Hy-b0234

177. To_000049

178. Estrone 100 Microg/ml In Methanol

179. Tox21_113567

180. Tox21_201375

181. Tox21_303651

182. Tox21_500513

183. Bbl033470

184. Bl-090

185. Lmst02010004

186. S1665

187. Stk801833

188. Zinc13509425

189. Estrone 1000 Microg/ml In Methanol

190. Akos005622512

191. Akos007930641

192. Tox21_113567_1

193. Ac-1395

194. Ccg-204604

195. Db00655

196. Ds-6316

197. Estrone 100 Microg/ml In Acetonitrile

198. Lp00513

199. Sdccgsbi-0050497.p002

200. Smp1_000123

201. Ncgc00023643-03

202. Ncgc00023643-04

203. Ncgc00023643-05

204. Ncgc00023643-06

205. Ncgc00023643-07

206. Ncgc00023643-08

207. Ncgc00023643-09

208. Ncgc00023643-10

209. Ncgc00023643-11

210. Ncgc00023643-12

211. Ncgc00023643-13

212. Ncgc00023643-15

213. Ncgc00023643-16

214. Ncgc00023643-22

215. Ncgc00179433-01

216. Ncgc00179433-02

217. Ncgc00179433-03

218. Ncgc00257402-01

219. Ncgc00258926-01

220. Ncgc00261198-01

221. Estrone, Meets Usp Testing Specifications

222. D1,3,5(10)-estratrien-3-ol-17-one

223. 3-hydroxyl-1,3,5(10)-estratien-17-one

224. 3-hydroxyoestra-1,3,5(10)-trien-17-one

225. Ab00382990

226. Estrone, Vetranal(tm), Analytical Standard

227. Eu-0100513

228. 3-hydroxy-estra-1,3,5(10)-triene-17-one

229. C00468

230. D00067

231. Ab00382990-16

232. Ab00382990-17

233. Ab00382990_18

234. Estra-1(10),2,4-trien-17-one, 3-hydroxy-

235. Ethinylestradiol Impurity C [ep Impurity]

236. 003e620

237. Q414986

238. Sr-01000000085

239. Sr-01000075867

240. Q-201073

241. Sr-01000000085-3

242. Sr-01000075867-1

243. Brd-k81839095-001-04-6

244. Brd-k81839095-001-30-1

245. Estradiol Hemihydrate Impurity A [ep Impurity]

246. 86c77018-146d-4603-acea-ca0d8c4f1e2c

247. Estrone, European Pharmacopoeia (ep) Reference Standard

248. Z1695906713

249. Estrone, United States Pharmacopeia (usp) Reference Standard

250. Estrone, Pharmaceutical Secondary Standard; Certified Reference Material

251. Estrone Solution, 1.0 Mg/ml In Methanol, Ampule Of 1 Ml, Certified Reference Material

252. (1s,10r,11s,15s)-5-hydroxy-15-methyltetracyclo[8.7.0.0;{2,7}.0;{11,15}]heptadeca-2,4,6-trien-14-one

253. (8r,13s)-3-hydroxy-13-methyl-6,7,8,9,11,12,13,14,15,16-decahydro-cyclopenta[a]phenanthren-17-one

2.4 Create Date
2004-09-16
3 Chemical and Physical Properties
Molecular Weight 270.4 g/mol
Molecular Formula C18H22O2
XLogP33.1
Hydrogen Bond Donor Count1
Hydrogen Bond Acceptor Count2
Rotatable Bond Count0
Exact Mass270.161979940 g/mol
Monoisotopic Mass270.161979940 g/mol
Topological Polar Surface Area37.3 Ų
Heavy Atom Count20
Formal Charge0
Complexity418
Isotope Atom Count0
Defined Atom Stereocenter Count4
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count1
4 Drug and Medication Information
4.1 Therapeutic Uses

Estrogens

National Library of Medicine's Medical Subject Headings online file (MeSH, 2009)


Esterified Estrogens and Methyltestosterone Tablets H.S. and Esterified Estrogens and Methyltestosterone Tablets D.S. are indicated in the: Treatment of moderate to severe vasomotor symptoms associated with the menopause in those patients not improved by estrogens alone. (There is no evidence that estrogens are effective for nervous symptoms or depression without associated vasomotor symptoms, and they should not be used to treat such conditions.) /Included in US product label/

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 28, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


/Estrone is indicated as/ Hormone replacement therapy (HRT) for estrogen deficiency symptoms in peri- and post-menopausal women. Prevention of osteoporosis in post-menopausal women at high risk of future fractures who are intolerant of, or contraindicated for, other medicinal products approved for the prevention of osteoporosis.

Datapharm Communications Ltd; Electronic Medicines Compendium (eMC), Summary of Product Characteristics (SPC) for Hormonin Tablets (Last updated December 2007). Available from, as of March 8, 2011: https://www.medicines.org.uk/EMC/medicine/20688/SPC/Hormonin+Tablets/#PHARMACOLOGICAL_PROPS


Esterified estrogens /is indicated/ for replacement in female hypogonadism...

American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 3139


For more Therapeutic Uses (Complete) data for ESTRONE (9 total), please visit the HSDB record page.


4.2 Drug Warning

ESTROGENS INCREASE THE RISK OF ENDOMETRIAL CANCER: Close clinical surveillance of all women taking estrogens is important. Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding. There is no evidence that the use of "natural" estrogens results in a different endometrial risk profile than synthetic estrogens at equivalent estrogen doses.

US Natl Inst Health; DailyMed. Current Medication Information ENJUVIA (synthetic conjugated estrogens, b) tablet (March 2010). Available from, as of February 22, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=22407


CARDIOVASCULAR AND OTHER RISKS: Estrogens with or without progestins should not be used for the prevention of cardiovascular disease or dementia. The estrogen alone substudy of the Women's Health Initiative (WHI) reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 6.8 years and 7.1 years, respectively, of treatment with oral conjugated estrogens (CE 0.625 mg) alone per day, relative to placebo.

US Natl Inst Health; DailyMed. Current Medication Information ENJUVIA (synthetic conjugated estrogens, b) tablet (March 2010). Available from, as of February 22, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=22407


The Women's Health Initiative Memory Study (WHIMS), a substudy of WHI, reported increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with oral conjugated estrogens plus medroxyprogesterone acetate relative to placebo. It is unknown whether this finding applies to younger postmenopausal women or to women taking estrogen alone therapy. Other doses of oral conjugated estrogens with medroxyprogesterone acetate, and other combinations and dosage forms of estrogens and progestins were not studied in the WHI clinical trials and, in the absence of comparable data, these risks should be assumed to be similar. Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 28, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


Other doses of oral conjugated estrogens with medroxyprogesterone acetate, and other combinations and dosage forms of estrogens and progestins were not studied in the WHI clinical trials and, in the absence of comparable data, these risks should be assumed to be similar. Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 28, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


For more Drug Warnings (Complete) data for ESTRONE (45 total), please visit the HSDB record page.


4.3 Drug Indication

For management of perimenopausal and postmenopausal symptoms.


5 Pharmacology and Biochemistry
5.1 Pharmacology

Estrone, a synthetically prepared or naturally occurring steroidal estrogen obtained from pregnant equine urine, is the primary circulating estrogen after menopause. Estrone is naturally derived from the peripheral conversion of androstenedione by an aromatase enzyme found in adipose tissues and is converted to estradiol in peripheral tissues. The estrogenic potency of estrone is one third that of estradiol. Estropipate is piperazine-stabilized estrone sulfate. Estrone, and estropipate are used to treat abnormalities related to gonadotropin hormone dysfunction, vasomotor symptoms, atrophic vaginitis, and vulvar atrophy associated with menopause, and for the prevention of osteoporosis due to estrogen deficiency.


5.2 MeSH Pharmacological Classification

Estrogens

Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds. (See all compounds classified as Estrogens.)


5.3 ATC Code

G - Genito urinary system and sex hormones

G03 - Sex hormones and modulators of the genital system

G03C - Estrogens

G03CA - Natural and semisynthetic estrogens, plain

G03CA07 - Estrone


G - Genito urinary system and sex hormones

G03 - Sex hormones and modulators of the genital system

G03C - Estrogens

G03CC - Estrogens, combinations with other drugs

G03CC04 - Estrone


5.4 Absorption, Distribution and Excretion

Absorption

43%


The natural estrogens are generally quickly and well absorbed from the gastrointestinal tract, there being little difference between estrone, estradiol and estriol. Estrogens are inactivated in the liver. A proportion of absorbed estrogen is excreted in the bile and then reabsorbed from the intestine.

Datapharm Communications Ltd; Electronic Medicines Compendium (eMC), Summary of Product Characteristics (SPC) for Hormonin Tablets (Last updated December 2007). Available from, as of March 8, 2011: https://www.medicines.org.uk/EMC/medicine/20688/SPC/Hormonin+Tablets/#PHARMACOLOGICAL_PROPS


The distribution of exogenous estrogens is similar to that of endogenous estrogens. Estrogens are widely distributed in the body and are generally found in higher concentrations in the sex hormone target organs. Estrogens circulate in the blood largely bound to sex hormone binding globulin (SHBG) and albumin.

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 22, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


Following administration of Hormonin, physiological estrogen concentrations are achieved at different rates. The maximum plasma levels and the time to reach the peak in the plasma level varied between subjects and was; estrone 750-2116 pmol/litre, 0.5-6.0 hours; estradiol 246-813 pmol/litre, 1-8 hours; estriol 173-241 pmol/litre, 5-12 hours. Following steady state conditions after cessation of Hormonin therapy, estrogen levels remained in the pre-menopausal range for approximately 48 hours.

Datapharm Communications Ltd; Electronic Medicines Compendium (eMC), Summary of Product Characteristics (SPC) for Hormonin Tablets (Last updated December 2007). Available from, as of March 8, 2011: https://www.medicines.org.uk/EMC/medicine/20688/SPC/Hormonin+Tablets/#PHARMACOLOGICAL_PROPS


Estrogens are available for oral, parenteral, transdermal, or topical administration ... absorption is generally good with the appropriate preparation. /Estrogens/

Hardman, J.G., L.E. Limbird, P.B. Molinoff, R.W. Ruddon, A.G. Goodman (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 9th ed. New York, NY: McGraw-Hill, 1996., p. 1419


For more Absorption, Distribution and Excretion (Complete) data for ESTRONE (11 total), please visit the HSDB record page.


5.5 Metabolism/Metabolites

Hepatic.


Exogenous estrogens are metabolized in the same manner as endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium of metabolic interconversions. These transformations take place mainly in the liver. Estradiol is converted reversibly to estrone, and both can be converted to estriol, which is the major urinary metabolite. Estrogens also undergo enterohepatic recirculation via sulfate and glucuronide conjugation in the liver, biliary secretion of conjugates into the intestine, and hydrolysis in the gut followed by reabsorption. In postmenopausal women, a significant proportion of the circulating estrogens exist as sulfate conjugates, especially estrone sulfate, which serves as a circulating reservoir for the formation of more active estrogens.

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 22, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


In the liver estradiol is readily oxidised to estrone and both estradiol and estrone are converted by hydration to estriol. Metabolites of estrogens are mainly excreted in the urine as conjugates of glucuronic and sulphuric acid.

Datapharm Communications Ltd; Electronic Medicines Compendium (eMC), Summary of Product Characteristics (SPC) for Hormonin Tablets (Last updated December 2007). Available from, as of March 8, 2011: https://www.medicines.org.uk/EMC/medicine/20688/SPC/Hormonin+Tablets/#PHARMACOLOGICAL_PROPS


The 17beta-hydroxy steroid dehydrogenase transforms estrone to estradiol reversibly. This enzyme occurred in all tissues of all species examined and is linked to either the cytosolic or microsomal subcellular compartment. In human liver, a NAD-linked 17beta-hydroxy steroid 3-hydrogenase occurs in cytosol and in microsomes, and a further NADP-linked enzyme has been found in cytosol. Hence, estrone and estradiol are largely biologically equivalent; they are also metabolized via the same pathways.

IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V21 356 (1979)


The steroidal estrogens are metabolized principally in the liver, although the kidneys, gonads, and muscle tissues may be involved to some extent. The steroids and their metabolites are conjugated at the hydroxyl group of the C 3 position with sulfuric or glucuronic acid; these conjugates may undergo further metabolic change. Conjugation increases water solubility and facilitates excretion in urine. Large amounts of free estrogens are also distributed into the bile, reabsorbed from the GI tract, and recirculated through the liver where further degradation occurs. /Estrogen General Statement/

American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 3131


For more Metabolism/Metabolites (Complete) data for ESTRONE (13 total), please visit the HSDB record page.


Estrone has known human metabolites that include (2S,3S,4S,5R)-3,4,5-Trihydroxy-6-[[(8R,9S,13S,14S)-13-methyl-17-oxo-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-3-yl]oxy]oxane-2-carboxylic acid.

S73 | METXBIODB | Metabolite Reaction Database from BioTransformer | DOI:10.5281/zenodo.4056560


5.6 Biological Half-Life

19 hours


5.7 Mechanism of Action

Estrogens enter the cells of responsive tissues (e.g. female organs, breasts, hypothalamus, pituitary) where they interact with estrogen receptors. Hormone-bound estrogen receptors dimerize, translocate to the nucleus of cells and bind to estrogen response elements (ERE) of genes. Binding to ERE alters the transcription rate of affected genes. Estrogens increase the hepatic synthesis of sex hormone binding globulin (SHBG), thyroid-binding globulin (TBG), and other serum proteins and suppress follicle-stimulating hormone (FSH) release from the anterior pituitary.


Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol at the receptor level. ... Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. To date, two estrogen receptors have been identified. These vary in proportion from tissue to tissue. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.

US Natl Inst Health; DailyMed. Current Medication Information EEMT H.S. (estrone sodium sulfate and methyltestosterone) tablet, coated (May 2010). Available from, as of February 28, 2011: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=23251


Estrogens have an important role in the reproductive, skeletal, cardiovascular, and central nervous systems in women, and act principally by regulating gene expression. Biologic response is initiated when estrogen binds to a ligand-binding domain of the estrogen receptor resulting in a conformational change that leads to gene transcription through specific estrogen response elements (ERE) of target gene promoters; subsequent activation or repression of the target gene is mediated through 2 distinct transactivation domains (ie, AF-1 and AF-2) of the receptor. The estrogen receptor also mediates gene transcription using different response elements (ie, AP-1) and other signal pathways. Recent advances in the molecular pharmacology of estrogen and estrogen receptors have resulted in the development of selective estrogen receptor modulators (eg, clomiphene, raloxifene, tamoxifen, toremifene), agents that bind and activate the estrogen receptor but that exhibit tissue-specific effects distinct from estrogen. Tissue-specific estrogen-agonist or -antagonist activity of these drugs appears to be related to structural differences in their estrogen receptor complex (eg, specifically the surface topography of AF-2 for raloxifene) compared with the estrogen (estradiol)-estrogen receptor complex. A second estrogen receptor also has been identified, and existence of at least 2 estrogen receptors (ER-alpha, ER-beta) may contribute to the tissue-specific activity of selective modulators. While the role of the estrogen receptor in bone, cardiovascular tissue, and the CNS continues to be studied, emerging evidence indicates that the mechanism of action of estrogen receptors in these tissues differs from the manner in which estrogen receptors function in reproductive tissue. /Estrogen General Statement/

American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 3130


Intracellular cytosol-binding proteins for estrogens have been identified in estrogen-responsive tissues including the female genital organs, breasts, pituitary, and hypothalamus. The estrogen-binding protein complex (ie, cytosol-binding protein and estrogen) distributes into the cell nucleus where it stimulates DNA, RNA, and protein synthesis. The presence of these receptor proteins is responsible for the palliative response to estrogen therapy in women with metastatic carcinoma of the breast. /Estrogen General Statement/

American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 3130


Estrogens have generally favorable effects on blood cholesterol and phospholipid concentrations. Estrogens reduce LDL-cholesterol and increase HDL-cholesterol concentrations in a dose-related manner. The decrease in LDL-cholesterol concentrations associated with estrogen therapy appears to result from increased LDL catabolism, while the increase in triglyceride concentrations is caused by increased production of large, triglyceride-rich, very-low-density lipoproteins (VLDLs); changes in serum HDL-cholesterol concentrations appear to result principally from an increase in the cholesterol and apolipoprotein A-1 content of HDL2- and a slight increase in HDL3-cholesterol. /Estrogen General Statement/

American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 3130


For more Mechanism of Action (Complete) data for ESTRONE (7 total), please visit the HSDB record page.