Approved for medical use in 2001, Ethinylestradiol/etonogestrel is a flexible birth control vaginal ring that contains two types of hormones, etonogestrel and ethinyl estradiol. Basically, this vaginal ring works by stopping a woman's egg from fully developing each month. In other words, the egg can no longer accept a sperm, and fertilization (pregnancy) cannot happen (as long as the ring is still inserted into the vagina). Bear in mind that Ethinylestradiol/etonogestrel will not prevent HIV infection or other sexually transmitted diseases. Besides, it will not prevent emergency contraception, such as after unprotected sexual contact. When it comes to the side effects of this vaginal ring, they include irregular vaginal bleeding, nausea, sore breasts, vaginitis, mood changes, and headache. Ethinylestradiol/etonogestrel has other side effects, albeit a bit more serious such as blood clots, toxic shock syndrome, anaphylaxis, gallstones, and liver problems. It is worth noting that the use of Ethinylestradiol/etonogestrel is not recommended in those who both smoke and are over the age of 35. And while use in pregnancy is not recommended, this hormonal ring has not been found to be harmful to the baby. However, use during breastfeeding is typically not recommended as it may decrease the milk supply.