The idea builds on a trend that is helping women obtain birth control more easily. A growing number of smartphone apps and websites now make it possible to get prescription contraceptives without visiting a doctor’s office first. The pills Marie and the other women received through the study are not allowed for sale in pharmacies and are usually available only at hospitals and abortion clinics.

Australia and the Canadian province of British Columbia allow women to get abortion pills by mail after consulting with a physician or other health care provider via phone or the internet. Several international organizations offer mail service in countries where abortion is otherwise unavailable or severely restricted. The oldest group, Women on Web, based in the Netherlands, has provided abortion medications to about 50,000 women in 130 countries since 2006. The service is not available in the United States, and the Food and Drug Administration warns against buying the drugs over the internet.

Having the pills delivered to her home in Hawaii meant that Marie could avoid the cost and time of traveling by plane to the nearest abortion clinic, over 100 miles away in Honolulu or Maui. Once she received them, she set the package aside for a week in her bedroom, waiting until she could schedule time off from her job at McDonald’s.

The first pill, as expected, had little effect. The next morning, with her mother at her home to watch her toddler, she took the second. Almost immediately, the bleeding and cramping began. Within three hours, her eight-week pregnancy was over. She described the pain as a five on a 10-point scale. That night she cooked dinner for her family, and the next day she went back to work.

The study Marie participated in is being conducted in four states — Hawaii, New York, Oregon and Washington. It is being funded and organized by Gynuity Health Projects, a nonprofit research group focused on reproductive health services that seeks to improve women’s access to medical abortions. The F.D.A. has allowed the experiment. Women learn about it when contacting the abortion clinics in the study and other health providers who are aware of the trial.