Population Council Research that makes a difference

In vivo and in vitro studies suggest that Nestorone has greater antiestrogenic activity than two other synthetic progestins, levonorgestrel and ketodesogestrel. A short-term study in rats also showed that Nestorone did not increase angiotensinogen mRNA levels in the liver as is the case with estrogens. A two-year carcinogenicity study in rats indicated that Nestorone is not toxic and has no potential for causing cancer. Another carcinogenicity study in mice is planned to start this year. An additional study—evaluating the metabolites of Nestorone in humans—will also start this year.

The Population Council’s radioimmunoassay core laboratory facilitates the clinical trial development program of the organization’s proprietary product Nestorone. The laboratory performs radioimmunoassay measurements of serum samples for Nestorone and for levonorgestrel as well as other steroids used in clinical trials conducted by the Council's International Committee for Contraception Research. Routine assays using commercial radioimmunoassay kits are also being performed as required.