Diethylstilbestrol is a synthetic non-steroidal estrogen that was historically widely used to prevent potential miscarriages by stimulating the synthesis of estrogen and progesterone in the placenta (in the United States of America, especially from the 19 + some more technical info). Chemically it is a trans-stilbene derivative with two para-hydroxylated phenyl rings linked by an ethylene bridge, molecular formula C18H20O2 and molar mass 268.35 g/mol. The compound is a potent agonist of estrogen receptors ER alpha and ER beta, showing high affinity and prolonged receptor activation relative to many endogenous estrogens. Key physicochemical properties include low aqueous solubility, good solubility in organic solvents such as ethanol and chloroform, a melting point in the range reported around 172 to 174 degrees Celsius and a phenolic pKa in the low double digits. Metabolism occurs primarily by hepatic hydroxylation and conjugation with glucuronide and sulfate, with enterohepatic recirculation contributing to persistence. Clinical and toxicological history includes its mid 20th century obstetric and endocrinologic applications and the later recognition of multigenerational reproductive toxicity and carcinogenic risk that led to cessation of routine pediatric and obstetric use in most jurisdictions.
Parent: Diethylstilbestrol
Parent: Diethylstilbestrol
Parent: Diethylstilbestrol
Pharmaceutical grade material is typically controlled to high purity with assay specifications commonly at or above 98 percent by validated HPLC or GC methods, and total impurities often limited to 2 percent or less. Typical related substances to monitor include the cis isomer of diethylstilbestrol, dimerization and oligomerization products formed under oxidative or thermal stress, hydrogenated stilbene derivatives such as hexestrol, and oxidative phenolic degradation products; individual related compound limits are commonly set below 0.5 percent and often below 0.1 percent for specified impurities depending on the monograph or supplier specification. Analytical control includes identity tests by NMR and IR, retention time matching by HPLC-UV, and mass spectrometric confirmation for unknowns. Residual solvent limits follow ICH Q3C guidance with common solvents such as toluene and methanol controlled to parts per million levels, water content controlled by Karl Fischer typically below 0.5 percent, and heavy metals limited to low ppm levels through ICP-MS or AAS testing. Stability monitoring focuses on avoidance of isomerization and oxidative degradation with storage recommended in airtight, light-protected containers at controlled temperature.
Historically it was used to reduce the perceived risk of miscarriage and for estrogen replacement and endocrine indications; it has also been used in the past for certain hormone-sensitive cancers and as a research tool to study estrogen receptor pharmacology.
Routine clinical use for preventing miscarriage has been discontinued in most countries because of documented risks to exposed offspring and mothers; limited use remains only in specific research settings or in legacy uses governed by national regulations and specialist oversight.
After its synthesis in the late 1930s it was originally marketed as a synthetic estrogen for menopausal symptoms and then widely prescribed from the 1940s onward during pregnancy to prevent miscarriage and related complications before safety concerns emerged.
DES syndrome refers to a spectrum of adverse outcomes observed in individuals exposed in utero to diethylstilbestrol, including reproductive tract malformations, infertility, increased risk of ectopic pregnancy and preterm delivery, and a rare increased risk of clear cell adenocarcinoma of the vagina and cervix; exposed males can show epididymal and testicular abnormalities and potential fertility effects, and exposed mothers have been linked with increased breast cancer risk.
