Diethylstilbestrol as a “morning after” contraceptive

In 1973, the FDA considered DES safe as ‘morning-after’ pill


Diethylstilbestrol (DES) is a nonsteroidal synthetic estrogen. It has been approved as a “morning-after” contraceptive.

It is thought to interfere with the implantation of the fertilized ovum. Among 5593 women treated with DES or other estrogens, 26 pregnancies have been reported. Most of these patients reported midcycle exposures.

Of 92 patients with adenocarcinoma of the vagina or cervix, prenatal histories of 66 were obtained. The mothers of 49 of them had taken DES or related nonsteroidal estrogens during pregnancy. In 1 case the mother had received only 1.5 mg daily. Another mother was treated for only 5 days during the first trimester. There is no evidence that the use of DES increases the risk of cancer in the mother.

The Food and Drug Administration has approved the use of DES as an emergency treatment only. Early therapeutic abortion is recommended when this use of DES fails, because of the possibility of a teratogenic effect.

The recommended oral dosage is 25 mg twice daily for 5 consecutive days, begun within 72 hours after sexual exposure. Severe nausea and vomiting may occur. Headaches and menstrual irregularities have also been reported.


  • Diethylstilbestrol as a “morning after” contraceptive, The Medical letter on drugs and therapeutics, NCBI PubMed PMID: 4740292, 1973 Jun 6.
  • Featured image stayathomemum.

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