According to NuvaRing, when used properly, the NuvaRing is 98 percent effective. Planned Parenthood supports that data claiming that this birth control form is very effective for most women. The vaginal ring works by being placed inside the vagina for three weeks, and then removing it for one week before replacing it with a new ring.
Planned Parenthood mentions that less than 1 in 100 women become pregnant when using NuvaRing correctly. If the birth control method is not used as directed, 8 in 100 women may become pregnant. The most common reason women become pregnant on NuvaRing is forgetting to replace the old vaginal ring with a new vaginal ring.
The NuvaRing releases estrogen and progestin to prevent unwanted pregnancies. Planned Parenthood explains that the NuvaRing functions the same way as oral birth control pills, preventing the release of an egg from the ovaries.
Certain drugs and herbs interact with the vaginal ring to make it less effective. Planned Parenthood says that the antibiotic rifampin, certain HIV medications, St. John's wort, certain anti-seizure medications and specific oral anti-yeast medications negatively interact with the NuvaRing.
Planned Parenthood cautions that women using the NuvaRing may experience spotting, vomiting, nausea and breast tenderness during the first three months of using this birth control method. Longer-term side effects include increased vaginal discharge, loss of libido and vaginal infection.