FDA considers DES safe as ‘morning-after’ pill

25 mg of DES twice daily for five days…


Food and Drug Administration approval of labeling for diethylstilbestrol (DES) as a postcoital contraceptive is reported.

DES is considered safe only as an emergency contraceptive measure.

The recommended dose is 25 mg twice a day for 5 days.

Treatment should be initiated 24-72 hours after coitus. It is important that the full regimen be completed, even if nausea, which is common with oral DES, is present.

There is yet no evidence that DES poses a significant carcinogenic risk to the mother or the fetus. However, if treatment fails, abortion should be seriously considered because of possible teratogenic effects or carcinoma in female offspring.

Medical News, June 18, 1973

Labeling for diethylstilbestrol (DES) has been approved to recommend restricted use of the drug as a “morning-after” contraceptive.

The Food and Drug Administration said it considers DES safe for this use “only as an emergency measure,” and warned against routine or frequent use of the drug as a contraceptive. This means, according to the FDA statement, that DES should be considered only in situations such as rape and incest, or where, in the physician’s judgment, the patient’s physical or mental well-being is in jeopardy.

The efficacy of DES in preventing pregnancy depends both on the dosage and time lapse after coitus. The recommended dosage is 25 mg twice daily for five days, preferably beginning within 24 hours and not later than 72 hours after coitus.

“When this dosage is given within the specified time interval after sexual intercourse, DES is highly effective in preventing conception,” FDA said. “But the patient must be warned to take the full course of the drug in spite of the nausea which commonly occurs, if it is to be effective.”

The agency urged physicians to inform patients or guardians of the possible side-effects of DES, and of alternative measures and their hazards.

“There is at present no positive evidence that the restricted postcoital use of DES carries a significant carcinogenic risk, either to the mother or fetus,” according to the FDA’s latest (May) Drug Bulletin.

If DES treatment fails, however, there should be “serious consideration of voluntary termination of pregnancy,” FDA said. This is because data support the possibility of delayed appearance of carcinoma in females whose mothers have been given DES later in pregnancy, and because teratogenic and other adverse effects on the fetus are not yet well understood.


  • FDA considers DES safe as ‘morning-after’ pill, JAMA Network PMID: 12257949, 1973 Jun.
  • More about DES (as Emergency contraception) and the FDA on wikivisually (mid-page).
  • Featured image TS Radio.

2 Replies to “FDA considers DES safe as ‘morning-after’ pill”

  1. My name is Juanita and I was given DES as a Morning After Treatment after a rape. I did suffer Adenocarcinoma and full Hysterectomy 5-6 years after treatment. I recently was diagnosed with Breast Cancer and had a bilateral mastectomy. Two months ago I was diagnosed with Endocrine irregularities including growth on my Adrenal Gland along with once again having an irregular Pap. What other proof is needed, I am a living testament that DES causes harm as a Morning After. I was rendered sterile after the Morning After thus no children. Perhaps there need to be a study done. I am willing.

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