The TDF-IVR would unwanted pregnancy and protect women against STD's, including AIDS.
It was developed by an associate professor at Northwestern University, in Illinois.
The idea isn't a new one, but Patrick Kiser figured out the right types of plastic to use that could reliably release the two different drugs at different rates and in the proper amounts.
"You can think of this as kind of a chemical condom," Kiser said.
The research was published in September in the Proceedings of the National Academy of Sciences.
Sixty women were fitted with the ring in November, and studied for 14 days.
Now, scientists are pouring over data from the trial, hoping to have the ring on the market in the next seven years.