ChemicalBook >> CAS DataBase List >>Estriol

Estriol

CAS No.
50-27-1
Chemical Name:
Estriol
Synonyms
(16alpha,17beta)-Estra-1,3,5(10)-triene-3,16,17-triol;ESTRA-1,3,5(10)-TRIENE-3,16,17-TRIOL;E 3;OVESTIN;Oestriol;16α-Estriol;16α-Hydroxyestradiol;1,3,5(10)-Estratriene-3,16α,17β-triol, 16α-Hydroxyestradiol, 3,16α,17β-Trihydroxy-1,3,5(10)-estratriene;Estriol,1,3,5(10)-Estratriene-3,16α,17β-triol, 16α-Hydroxyestradiol, 3,16α,17β-Trihydroxy-1,3,5(10)-estratriene;(8R,9S,13S,14S,16R,17R)-13-Methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthrene-3,16,17-triol
CBNumber:
CB1687589
Molecular Formula:
C18H24O3
Molecular Weight:
288.38
MDL Number:
MFCD00003691
MOL File:
50-27-1.mol
MSDS File:
SDS
TDS File:
TDS
Last updated:2026-08-31 08:25:04

Estriol Properties

Melting point 280-282 °C(lit.)
alpha D25 +58° ±5° (0.04 g in 1 ml dioxane)
Boiling point 370.61°C (rough estimate)
Density 1.27
refractive index 58 ° (C=0.4, Dioxane)
Flash point 9℃
storage temp. 2-8°C
solubility Practically insoluble in water, sparingly soluble in ethanol (96 per cent).
form Solid
pka pKa 10.38±0.02(H2O t=23±2 Iunspecied) (Uncertain)
color White to Off-White
optical activity +6127 (95% ethanol)
Water Solubility 3.2mg/L(25 ºC)
Merck 3707
BRN 2508172
Henry's Law Constant 7.6×106 mol/(m3Pa) at 25℃, HSDB (2015)
InChI 1S/C18H24O3/c1-18-7-6-13-12-5-3-11(19)8-10(12)2-4-14(13)15(18)9-16(20)17(18)21/h3,5,8,13-17,19-21H,2,4,6-7,9H2,1H3/t13-,14-,15+,16-,17+,18+/m1/s1
InChIKey PROQIPRRNZUXQM-ZXXIGWHRSA-N
SMILES C[C@]12CC[C@H]3[C@@H](CCc4cc(O)ccc34)[C@@H]1C[C@@H](O)[C@@H]2O
CAS DataBase Reference 50-27-1(CAS DataBase Reference)
EWG's Food Scores 1
FDA UNII FB33469R8E
ATC code G03CA04,G03CC06
NIST Chemistry Reference Estriol(50-27-1)
EPA Substance Registry System Estriol (50-27-1)
UNSPSC Code 41116107
NACRES NA.24

SAFETY

Risk and Safety Statements

Symbol(GHS)  Health Hazard (GHS08)
GHS08
Signal word  Danger
Hazard statements  H351-H360FD-H362
Precautionary statements  P201-P202-P260-P263-P264-P308+P313
PPE Eyeshields, Gloves, type P3 (EN 143) respirator cartridges
Hazard Codes  T,F
Risk Statements  60-61-40-45-39/23/24/25-23/24/25-11
Safety Statements  53-22-36/37/39-45-36/37-16
RIDADR  UN1230 - class 3 - PG 2 - Methanol, solution
WGK Germany  3
RTECS  KG8225000
8-10
HS Code  29072990
Storage Class 6.1C - Combustible acute toxic Cat.3
toxic compounds or compounds which causing chronic effects
Hazard Classifications Carc. 2
Lact.
Repr. 1A
Hazardous Substances Data 50-27-1(Hazardous Substances Data)
Toxicity LD50 oral in rat: > 2gm/kg
NFPA 704
3
0 0

Estriol price More Price(82)

Manufacturer Product number Product description CAS number Packaging Price Updated Buy
Sigma-Aldrich Y0001971 Estriol for system suitability European Pharmacopoeia (EP) Reference Standard 50-27-1 10 mg $167 2026-04-30 Buy
Sigma-Aldrich PHR2800 Estriol certified reference material, pharmaceutical secondary standard 50-27-1 200MG $282 2026-04-30 Buy
Sigma-Aldrich E1680000 Estriol European Pharmacopoeia (EP) Reference Standard 50-27-1 70 mg $167 2026-04-30 Buy
Sigma-Aldrich E-074 Estriol solution 1.0?mg/mL in methanol, ampule of 1?mL, certified reference material, Cerilliant? 50-27-1 1mL $160 2026-04-30 Buy
Sigma-Aldrich BP752 Estriol British Pharmacopoeia (BP) Reference Standard 50-27-1 100MG $296 2026-04-30 Buy
Product number Packaging Price Buy
Y0001971 10 mg $167 Buy
PHR2800 200MG $282 Buy
E1680000 70 mg $167 Buy
E-074 1mL $160 Buy
BP752 100MG $296 Buy

Estriol Chemical Properties,Uses,Production

Natural hormone

Estriol belongs to natural hormone and is the metabolite of estradiol in vivo. It is mainly presented in the urine. Estrogen has a relative small activity with the oral activity being 6 times as high as estrone but being weaker than estradiol with non-carcinogenic effects. After its administration, the in vivo estradiol levels did not change. Estriol has selective action on the vaginal and cervical canal but has no effect on the uterus and endometrium entity. Animal experiments have shown that estriol has a stronger effect on vaginal epithelial keratosis than estradiol, thus being able to promote vaginal epithelial hyperplasia, superficial cells keratosis, mucosal angiogenesis and vaginal epithelial wound healing, but having a weak effect on the weight gain of mouse uterus. At the same time, estriol can enhance the function of cervix cell, causing the cervix muscle fiber hyperplasia and increasing the cervical elasticity and softness. In addition, estriol has feedback inhibition on the hypothalamus and pituitary but does not inhibit ovulation while only having significant impact on the corpus luteum and therefore can be used as the auxiliary drug in the medium-term labor induction and artificial abortion and for the treatment of various kinds of menopathy. Estriol also has significant effect on the hematopoietic system and can reduce vascular permeability and fragility. Therefore, it can be used for the treatment of various kinds of hemorrhage. It also has effect of rapidly increasing the peripheral leukocytes and generally begins to take effect at 1 to 3 days after treatment but with a shorter duration of action and is effective in treatment the leukopenia induced by radiotherapy and chemotherapy.
the formula of estriol
Figure 1 is the formula of estriol

Pharmacokinetics

It can be absorbed from the gastrointestinal tract and skin but is susceptible to damage upon oral administration and is therefore mainly subject to intramuscular injection and topical usage. It is metabolized in the body to less-active estrone and estriol and can be inactivated when being combined with glucuronic acid and sulfuric acid and further excreted in urine.

Indications

It can be used for treating cervicitis, especially suitable for treating menopausal syndrome and senile vaginitis. It can also be used as the adjuvant drug for middle-term labor induction and artificial abortion. It can also be used for treating prostatic hypertrophy and prostate cancer. In addition, it still has a rapid role in increasing the peripheral leukocytes. It generally takes effect at 1 to 3 days after the treatment but with a short duration period. It also has efficacy in treating leukopenia caused by chemotherapy or radiotherapy as well as reducing the vascular permeability and fragility and can be used for the treatment of various kinds of hemorrhage. It also has quick hemostasis effect on menorrhagia, hysterectomy or tonsillectomy.

Side effects

There are temporary breast swelling or lumps, menstrual disorders which can self-limiting and recovery after discontinuing the drug. In oral administration, it has been occasionally observed of loss of appetite, nausea, vomiting, abdominal pain and so on.

Determination of estriol content

Estriol is produced through the hydroxylation of carbon 16 in dehydroepiandrosterone at fetal adrenal; it further enters into the placenta and the metabolism by the placental syncytiotrophoblast cells. It is then released into the maternal blood with the free estriol absorbed by the maternal liver and further combined into glucuronic acid or sulfuric acid estriol that are further excreted by the kidneys. Therefore, the estriol in the urine is all in the form of conjugated estriol while the estriol in the blood contains both free type and bound type with free form accounting for about 10 to 30% and the rest being in bound form. Determination of estriol in the urine of pregnant women with a spectrophotometer has been widely used clinically. There are other common methods including radioimmunoassay. Estriol is not contained in the blood of non-pregnant women. According to the measurement of the Shanghai Second Medical Ruijin Hospital, upon 26 weeks of pregnancy, the plasma free estriol is 4~6ng/ml while upon 36 weeks, it is 10~12ng/ml and it is 19ng/ml or more in full term but with large individual differences. The total plasma estriol value, at 25 weeks of gestation, is 50ng/ml and is 200ng/ml at 40 weeks of pregnancy. At 24h, the urine estriol was 8.12 ± 0.28mg at 28 weeks of pregnancy and was 19.81 ± 8.28 mg in full term. It is generally believed that after 36 weeks of pregnancy, if the urine content at 24 h > 15mg, the value is normal; 12~10mg is alert value while <10mg is dangerous values. Since the major precursor of estriol during pregnancy comes from fetus, being different from the estrone and estradiol that is from the mother, the determination of estriol may reflect the condition of fetal development. When some fetal malformations and maternal or fetal diseases affect fetal development or cause fetal asphyxia, it is always accompanied of decrease of estriol. However, due to the great daily fluctuations of estriol level, it is generally measured for 4 to 5 times at least for some time in order to determine whether the level of estriol is really low. The estriol level in mild hypertension of pregnancy are often normal before 34 weeks while is maintained at low level after 34 weeks while the level significantly drops upon severe pregnancy-induced hypertension. For pregnant women upon exceeding the expected date, you can continuously measure the urinary estriol in 24h. If it is always higher than 25mg, you can still wait under close observation; if it is less than 10mg, the fetus is at risk and should be subject to positive treatment. Owing to lack of hypothalamus, non-brain child has pituitary hypoplasia and small adrenal gland. Since the supply of the raw material for the placental synthesis of estriol, 16-hydroxy isopropyl DHEA is in insufficient amount, the estriol in urine of pregnant women is very low with most being below the normal 10%.
The above information is edited by the chemicalbook of Dai Xiongfeng.

Purpose and Function

1. It can be used for treating cervicitis and especially suitable for treating menopausal syndrome and senile vaginitis.
2. It can also be used as the adjuvant drug for middle-term labor induction and artificial abortion. 3. It can also be used for treating prostatic hypertrophy and prostate cancer.
4. It still has a rapid role in increasing the peripheral leukocytes. It generally takes effect at 1 to 3 days after the treatment but with a short duration period. It also has efficacy in treating leukopenia caused by chemotherapy or radiotherapy.
5. It can be used for reducing the vascular permeability and fragility and can be used for the treatment of various kinds of hemorrhage. It also has quick hemostasis effect on menorrhagia, hysterectomy or tonsillectomy.

Precautions

1. Pregnant and lactating women, patients of breast hyperplasia, breast lumps, gynecological cancer, and aplastic anemia patients should be disabled with minor patients being not suitable for using it.
2. Patients of heart (liver, kidney) disease, hypertension, diabetes, epilepsy, migraine (including medical history), endometriosis, fibrocystic breasts, porphyria, hyperlipidemia or having history of pregnancy itching and herpes should take with caution.
3. If prescribed therapy doesn’t work, it is not suitable for increasing the dose or extending the usage time.

Drug Interactions

It can be used in combination with estradiol with competitive antagonism.

Storage

It should be sealed upon shading for storage.

Chemical Properties

It is white crystalline powder with the M.p. being 283 ℃, relative density being 1.27, and the specific rotation being [α] 25D + 34.4°(pyridine) and 25D + 58°± 5°(4%, dioxane). Its ethanol solution has maximum absorption at the wavelength of 280 nm. The crystal is insoluble in water, slightly soluble in ethanol (1: 500), diethyl ether, chloroform, dioxane and vegetable oil and easily soluble in pyridine and alkali hydroxide solution.

Uses

It belongs to estrogen drug. It can be used for treating leukopenia, various kinds of menopathy, senile vaginitis, and menopausal syndrome. You may also get temporary breast swelling and lumps, menstrual cycle disorders with self-recovery after stopping the drug for about 1 month. Patients of breast hyperplasia, breast lumps, and cancer potentially being related to female hormone-related cancer, aplastic anemia and liver disease patients should be disabled.

Production method

Take estrone as raw material; go through acetylation, epoxidation, and reduction to obtain the estriol products.
Estrone [acetylation] → [16, 17-epoxidation] → [rearrangement] → [Restore] → [hydrolysis] → finished product of estriol.
Estrone acetate successively goes through followed enolization, acetylation, epoxidation and reduction to obtain it.

Description

Estriol is significantly less active than estradiol; however, it has a selective ability to stimulate blood flow and restoration of genital epithelium. In addition, using this drug reduces mental symptoms of menopausal syndrome. It is used in the premenopausal and menopausal periods, for skin atrophy and signs of genital degeneration, and so on.

Description

Estriol is a metabolite of estradiol and a major estrogen produced in the later stages of pregnancy. In a longitudinal study in healthy pregnant women, total plasma estriol levels increased from <10 ng/ml at 8-10 weeks gestation to approximately 150 ng/ml at week 38. The majority of the estriol synthesized in the later stages of pregnancy originates from fetal dehydroepiandrosterone sulfate (DHEAS) and serves as a direct marker of fetal adrenal gland activity. Saliva contains primarily unbound and unconjugated estriol and is commonly used for monitoring estriol levels. Plasma levels of estriol in males and non-pregnant females is less than 2 ng/ml.

Chemical Properties

White or almost white, crystalline powder.

Uses

17b-estradiol metabolite, primary estrogen in urine

Uses

A metabolite of Estradiol. An estrogenic metabolite considerably less potent than the hormone Estradiol

Uses

A metabolite of Estradiol (E888000). An estrogenic metabolite considerably less potent than the hormone Estradiol (E888000).

Definition

ChEBI: A 3-hydroxy steroid that is estra-1,3,5(10)-trien-3-ol substituted by additional hydroxy groups at positions 16 and 17 (16alpha,17beta-stereoisomer).

brand name

Theelol (Parke-Davis).

General Description

Estriol, estra-1,3,5(10)-triene-3,16 ,17 -triol, is available for compounding into several differentformulations for use in HRT. It can be used alone or in combinationswith estradiol (Bi-Est) or with estradiol and estrone(Tri-Est).

Hazard

A carcinogen (OSHA).

Safety Profile

Suspected carcinogen with experimental carcinogenic, neoplastigenic, tumorigenic, and teratogenic data. Other experimental reproductive effects. Mutation data reported. A steroid drug for the treatment of menopause. When heated to decomposition it emits acrid smoke and irritating fumes.

Synthesis

Estriol, estra-1,3,5(10)-trien-3,16|á,17|-triol (28.1.25), is proposed to be synthesized from the methyl ester of estrone (28.1.8). Methyl ester of estrone is reacted with isopropenylacetate in the presence of p-toluenesulfonic acid, forming the corresponding enolacetate (28.1.23). The resulting enolacetate is oxidized to an epoxide using perbenzoic acid. The resulting epoxide (28.1.24) undergoes reduction by lithium aluminum hydride to.

Synthesis_50-27-1

Purification Methods

Crystallise estriol from EtOH/ethyl acetate. Also purify it by countercurrent distribution with cyclohexane/EtOAc (1:1) and EtOH/H2O (1:1). The UV (EtOH) has max at 280nm ( 2,090 M-1cm-1). [Huffmann & Lott 71 719 1949, Leeds et al. J Am Chem Soc 76 2943 1954, Beilstein 6 IV 7550.]

References

[1] M PETER  W G S  H G Drr. Changes in the concentrations of dehydroepiandrosterone sulfate and estriol in maternal plasma during pregnancy: a longitudinal study in healthy women throughout gestation and at term.[J]. Hormone research, 1994, 42 6: 278-281. DOI: 10.1159/000184209
[2] MD T M G. A role for estriol in human labor, term and preterm[J]. American journal of obstetrics and gynecology, 1999, 180 1: Pages S208-S213. DOI: 10.1016/s0002-9378(99)70702-7
[3] MICHAEL S KRAMER. Maternal stress/distress, hormonal pathways and spontaneous preterm birth.[J]. Paediatric and perinatal epidemiology, 2013, 27 3: 237-246. DOI: 10.1111/ppe.12042
[4] JULIA SEIBERT. Effects of MDMA and methylphenidate on steroid levels in healthy humans[J]. Toxicology letters, 2013, 221 1. DOI: 10.1016/j.toxlet.2013.05.067

566-76-7
50-27-1
Synthesis of Estriol from 1,3,5[10]-Estratriene-3,16alpha-diol-17-one
Global( 642)Suppliers
Supplier Tel Email Country ProdList Advantage
Wuhan Senwayer Century Chemical Co.,Ltd 027-86652399 sales@senwayer.com China 266 55
CHONGQING CHENCHENG PHARMACEUTICAL CO.,LTD. 15310426561 lf19823605252@163.com China 145 58
J & K SCIENTIFIC LTD. 18210857532 18210857532 jkinfo@jkchemical.com China 96815 76
Meryer (Shanghai) Chemical Technology Co., Ltd. 4006356688 18621169109 market03@meryer.com China 40202 62
3B Pharmachem (Wuhan) International Co.,Ltd. 18930552037 3bsc@sina.com China 15813 69
future industrial shanghai co., ltd 400-0066400 13621662912 sales@jonln.com China 1989 65
Chembest Research Laboratories Limited 021-20908456 sales@BioChemBest.com China 5996 61
TCI (Shanghai) Development Co., Ltd. 021-67121386 Sales-CN@TCIchemicals.com China 24512 81
Pure Chemistry Scientific Inc. 001-857-928-2050 or 1-888-588-9418 sales@chemreagents.com United States 10174 62
LGM Pharma 1-(800)-881-8210 inquiries@lgmpharma.com United States 2110 70

Related articles

  • What is Estriol?
  • Estriol is one of three estrogen hormones and is important for female development
  • Sep 14,2023

View Lastest Price from Estriol manufacturers

Image Update time Product Price Min. Order Purity Supply Ability Manufacturer
estriol pictures 2026-09-13 estriol
50-27-1
$1.00 300g 99.8% 20 TONS .GZ HONESTCHEM CO.,LTD
Estriol pictures 2026-09-13 Estriol
50-27-1
$1.00 1g 99% 1000kg RongNa Biotechnology Co.,Ltd
Estriol pictures 2026-09-11 Estriol
50-27-1
10g 97.0-102.0%,USP39 50kg/month WUHAN FORTUNA CHEMICAL CO., LTD
  • estriol pictures
  • estriol
    50-27-1
  • $1.00
  • 99.8%
  • .GZ HONESTCHEM CO.,LTD
  • Estriol pictures
  • Estriol
    50-27-1
  • $1.00
  • 99%
  • RongNa Biotechnology Co.,Ltd
  • Estriol pictures
  • Estriol
    50-27-1
  • 97.0-102.0%,USP39
  • WUHAN FORTUNA CHEMICAL CO., LTD
E 3 ESTRIOL ESTRA-1,3,5(10)-TRIENE-3,16ALPHA,17BETA-TRIOL TRIDESTRIN ESTRIOL(P) Estriol,1,3,5(10)-Estratriene-3,16α,17β-triol, 16α-Hydroxyestradiol, 3,16α,17β-Trihydroxy-1,3,5(10)-estratriene Estriol (100 mg) 1,3,5(10)-Estratriene-3,16α,17β-triol, 16α-Hydroxyestradiol, 3,16α,17β-Trihydroxy-1,3,5(10)-estratriene Estriol, Micronized 1,3,5-estratriene-3β,16α,17β-triol 16a-Hydroxyestradiol 3,16ALPHA,17BETA-TRIHYDROXY-1,3,5[10]-ESTRATRIENE 16ALPHA-HYDROXYESTRADIOL 16-ALPHA-HYDROXY 17-BETA-ESTRADIOL 1,3,5-ESTRATRIENE-3,16ALPHA, 17BETA-TRIOL 1,3,5[10]-ESTRATRIENE-3,16ALPHA,17BETA-TRIOL 1,3,5(10)-estratriene-3,16a,17b-triol 1,3,5(10)-ESTRATRIEN-3,16A,17BETA-TRIOL 1,3,5(10)-ESTRATRIEN-3, 16ALPHA, 17BETA-TRIOL Estriol Estratriol (16a,17)-Estra-1,3,5[10]-triene-3,16,17-triol Acifemine 16-alpha,17-beta-oestriol 16alpha,17beta-Oestriol 16alpha-Estriol 16-alpha-hydroxyoestradiol 16alpha-Hydroxyoestradiol 3,16-alpha,17-beta-estriol 3,16alpha,17beta-Estriol 3,16-alpha,17-beta-Oestriol 3,16-alpha,17-beta-trihydroxy-delta-1,3,5-estratriene 3,16alpha,17beta-Trihydroxy-delta-1,3,5-estratriene 3,16-alpha,17-beta-trihydroxy-delta-1,3,5-oestratriene 3,16alpha,17beta-Trihydroxy-delta-1,3,5-oestratriene 3,16-alpha,17-beta-trihydroxyestra-1,3,5(10)-triene Holin Hormomed Hormonin Klimax E Klimoral NSC-12169 OE3 Oestra-1,3,5(10)-triene-3,16alpha, 17beta-triol oestra-1,3,5(10)-triene-3,16-alpha,17-beta-triol Oestratriol Orestin Orgastyptin Ortho-Gynest Overstin Ovesterin Ovestinon Ovestrion Ovo-vinces Stiptanon Synapause Thulol Trihydroxyestrin Trihydroxyoestrin