The Population Council is developing a contraceptive gel that can be applied to the skin and contains the progestin Nestorone® and a form of estrogen called estradiol. Council Director of Clinical Development Ruth Merkatz presented results from a promising small study at the American Society for Reproductive Medicine in October 2010.
The colorless and odorless gel, provided to the Population Council by Antares Pharma, Inc., dries quickly and leaves no residue.
The Population Council evaluated three different doses of the gel applied on the woman's abdomen to determine which dose worked best to prevent ovulation (the monthly release of an egg from the ovary).
The study also evaluated gel safety and women's perceptions of using this gel as a contraceptive method.
Eighteen women in their 20s and 30s volunteered to be in the trial, which was conducted in Chile, the Dominican Republic, and the United States.
Each participant was instructed to use one of the three doses for 21 days. After a month of not using the gel, the woman then proceeded to the second dose for 21 days, followed by another month of nonuse before proceeding to the third and final testing cycle.
The women were asked to put a small amount of the gel on their abdomen once a day. They were instructed to cover the application site with clothes after the gel dried and to wash their hands after they had used the gel.
The study measured ovulation suppression. It did not measure whether or not the volunteers would get pregnant. In fact, the women in this study were not at risk of becoming pregnant. Some had a tubal ligation, others had partners with a vasectomy, but all volunteers were selected because they were not going to get pregnant.
The data demonstrated that the gel prevented ovulation in all women who used it as recommended.
The study results have helped the investigators determine the appropriate dose for preventing ovulation and ensuring that a proper level of estrogen is maintained in the woman's body.
There were no serious health concerns reported during the study.
Side effects that were reported were mild, such as a headache.
A majority of women in this small study reported that they found the gel easy to use and convenient.
This study did not evaluate the gel's impact on breastfeeding women. Contraceptives that contain estrogens are not recommended for use in breastfeeding women.
Additional studies will now need to be carried out in larger populations of women to evaluate whether the gel is effective in preventing pregnancy, how it affects the monthly bleeding patterns, and to confirm its safety on a larger scale.
If further studies continue to yield positive results, a product could be available to consumers in approximately five years.
This research is part of the Population Council's ongoing efforts to expand the array of effective, safe, affordable, and easy-to-use contraceptive options.