All Photos(4)




powder, ≥98% (TLC)

1,3,5(10)-Estratriene-3,17α-diol, 3,17α-Dihydroxy-1,3,5(10)-estratriene, Epiestradiol
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
EC Number:
MDL number:
PubChem Substance ID:

Quality Level

biological source

synthetic (organic)


≥98% (TLC)




white to slight yellow


ethanol: 50 mg/mL, clear, colorless

shipped in


storage temp.

room temp

SMILES string




InChI key


Gene Information

Looking for similar products? Visit Product Comparison Guide


1 g in glass bottle
100, 500 mg in glass bottle

Biochem/physiol Actions

Estradiol (known as alpha Estradiol or 17 alpha Estradiol) is a biologically active estrogen in human breast cancer cells in tissue culture.17-estradiol and its selective receptor, ER-X, are not part of a classical hormone/receptor endocrine system but of a system with important autocrine/paracrine functions in the developing and adult brain. 17-Estradiol may have enormous implications for hormone replacement strategies at the menopause and in the treatment of such neurodegenerative disorders as Alzheimer′s disease and ischemic stroke.


Health hazardEnvironment

Signal Word


Hazard Classifications

Aquatic Chronic 1 - Carc. 2 - Lact. - Muta. 2 - Repr. 1A

Storage Class Code

6.1C - Combustible, acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects



Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves

Certificate of Analysis

Certificate of Origin

  1. How does the storage temperature relate to shipping conditions?

    The storage conditions that a Sigma-Aldrich catalog and label recommend for products are deliberately conservative. For many products, long-term storage at low temperatures will increase the time during which they are expected to remain in specification and therefore are labeled accordingly. Where short-term storage, shipping time frame, or exposure to conditions other than those recommended for long-term storage will not affect product quality, Sigma-Aldrich will ship at ambient temperature. The products sensitive to short-term exposure to conditions other than their recommended long-term storage are shipped on wet or dry ice. Ambient temperature shipping helps to control shipping costs for our customers. At any time, our customers can request wet- or dry-ice shipment, but the special handling is at customer expense if our product history indicates that the product is stable for regular shipment. See Shipping and Storage for more information.

  2. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  3. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  4. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  5. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  6. How can I dissolve α-Estradiol, Product No. E8750?

    This chemical is soluble in ethanol at 50 mg/mL with heating, and in DMSO at 27 mg/mL. Use of freshly prepared solutions is recommended.

  7. What is the difference between α-Estradiol (Product No. E8750) and β-Estradiol?

    α-Estradiol has been reported as being less feminizing than β-Estradiol while still having significant biological properties.  See Moos, W.H., et al, "17α-Estradiol:a less-feminizing estrogen", Drug Development Research, 69(4), 177-184 (2008).

  8. Is Product E8750, α-Estradiol, tested in cell culture?

    No specific suitability tests for cell culture applications have been performed by Sigma. The product is not sterile and has not been tested for endotoxins.

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Raphaël Bonnet et al.
Frontiers in oncology, 10, 557643-557643 (2020-11-27)
T-cell Acute Lymphoblastic Leukemia (T-ALL) is an aggressive subtype of leukemia for which important progress in treatment efficiency have been made in the past decades to reach a cure rate of 75%-80% nowadays. It is nevertheless mandatory to find new
Wolf Dietrich et al.
Fertility and sterility, 95(4), 1247-1255 (2010-12-07)
To clarify, whether uterine endothelial proliferation could be regulated via an autocrine estrogen producing mechanism or direct actions of testosterone. In vitro study. Tertiary care facility. Human myometrial tissue obtained from 40 women undergoing hysterectomy without further intrauterine pathology. Cell
Jennifer R Wardell et al.
Biology of reproduction, 89(5), 116-116 (2013-09-27)
Estrogen signaling in the ovary is a fundamental component of normal ovarian function, and evidence also indicates that excessive estrogen is a risk factor for ovarian cancer. We have previously demonstrated that the gonadally enriched TFIID subunit TAF4B, a paralog
C Y Cheng et al.
Fertility and sterility, 32(5), 566-570 (1979-11-01)
In modified Tyrode's solution, 17 beta-estradiol at concentrations between 0.1 microgram/ml and 320 nmoles/ml was effective in increasing human spermatozoal forward migration. 17 alpha-Estradiol, although structurally similar to 17 beta-estradiol, had no effect on human spermatozoal motility. DL-Norgestrel at concentrations
J Pitt et al.
Journal of inherited metabolic disease, 25(2), 83-88 (2002-07-18)
Three patients with ketosis had increased excretion of 3-hydroxyglutarate (21.8-37.9 micromol/mmol creatinine; controls 2.3 +/- 1.6), an indicator of glutaryl-CoA dehydrogenase deficiency (GDHD), which normalized when the patients were nonketotic. Clinical assessment of all three patients and enzyme studies in


UHPLC Analysis of Conjugated Estrogens on Ascentis ® Express C18

Separation of Estriol 3-(β-D-glucuronide) sodium salt; β-Estradiol 3-(β-D-glucuronide) 17-sulfate dipotassium salt; Estriol 3-sulfate sodium salt; β-Estradiol 3,17-disulfate dipotassium salt, ≥95%; β-Estradiol 17-(β-D-glucuronide) sodium salt; β-Estradiol 3-(β-D-glucuronide) sodium salt; Estrone 3-(β-D-glucuronide) sodium salt; β-Estradiol 3-sulfate sodium salt, ≥93%; Estriol, ≥97%; Estrone 3-sulfate sodium salt, contains ~35% Tris as stabilizer; β-Estradiol, ≥98%; α-Estradiol, powder, ≥98% (TLC); Estrone, ≥99%

Related Content

UHPLC Analysis of Conjugated Estrogens on Titan™ C18

The Titan C18 column provided efficient and rapid resolution of thirteen related estrogenic compounds. Ultra Ultra high purity solvents provided robust operation.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service