The synthetic sex hormone stilboestrol (diethylstilboestrol, or in the USA stilbestrol) may be used as a vaginal pessary for female hormone replacement in menopause and vaginal dryness after the menopause. One or two pessaries are inserted high into the vagina at night.
It is not to be used in pregnancy, breastfeeding or children but accidental usage in these situations unlikely to be harmful. Use stilboestrol with caution in epilepsy, migraine, heart failure, high blood pressure, kidney disease, diabetes, porphyria or uterine disease. Do not take it if suffering from liver disease, breast or genital cancer, or blood clots.
Side effects may include abnormal uterine bleeding, vaginal thrush, fluid retention, weight gain and breast tenderness. Uncommonly a rash, bloating and intestinal cramps may occur. Severe but rare side effects include blood clots, calf or chest pain and yellow skin (jaundice). Smoking increases the risk of serious side effects. Interactions occur with other sex hormones.
It is now considered to be a rather old-fashioned form of hormone replacement therapy as other better suited hormones are now available, and its use is steadily declining.