Intravaginal administration of RU 486 in humans and rats: Inadequate absorption in humans

O. Heikinheimo, H. Croxatto, A. M. Salvatierra, C. C. Chang, T. Luukkainen, P. Lähteenmäki

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11 Citations (Scopus)


Vaginal absorption of the antiprogesterone steroid RU 486 was studied in humans and rat. In rats, RU 486 was sufficiently absorbed to terminate early pregnancy following vaginal, oral or intramuscular administration. The quantitation of RU 486 in serum showed that the ratios of the areas under the coocentration curves per mg administered were 1:2.8:3.4 for the vaginal, intramuscular and oral routes, respectively. Female voluteers received RU 486 vaginally in polyethylene glycol (PEG) suppositories, In tampons and in oil solution. Following vaginal (PEG-suppository) and oral a administration of 100 mg of RU 486, the ratio of the areas under the serum concentration curves was 1:56, respectively. From tampons and oil, RU 486 was absorbed in a similar manner to that of the PEG-suppositories, resulting in nanomolar serum concentrations. In humans no biological effects were noted following vaginal administration of RU 486. These data suggest that vaginal release of RU 486 is not a successful route of administration in humans.

Original languageEnglish
Pages (from-to)645-648
Number of pages4
JournalHuman Reproduction
Issue number8
Publication statusPublished - 1 Jan 1987


  • Antiprogesterone RU 486
  • Pharmacokinetics of RU 486
  • Polyethylene glycol suppository
  • Vaginal administration of RU 486

ASJC Scopus subject areas

  • Reproductive Medicine
  • Rehabilitation
  • Obstetrics and Gynaecology


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