If you haven't already heard about Essure, the controversial permanent birth control device, you're about to hear a lot more. Reports from women who blame Essure for a range of health complications, including rashes and chronic pain, have been mounting, but the patients haven't had much luck getting the U.S. Food and Drug Administration (FDA) to listen — until now. After evaluating a ton of information last fall, the FDA announced this week that it will require Essure's makers to perform a new study and to add a new boxed warning to the device.This is the strongest step the FDA has taken so far, but many questions remain.Essure was first approved in 2002 as a cheaper, less-invasive (but still permanent) birth control alternative to tubal ligation (a.k.a. "getting your tubes tied"). The device is a tiny metal coil placed directly into the fallopian tubes, which prevents pregnancy. But in the 14 years since then, thousands of women have reported complications they claim were caused by Essure. These include the device perforating the fallopian tubes or uterus as well as chronic pain, allergic reactions to nickel in the device, and other hypersensitivity reactions, like headaches and fatigue. A complaint based on a consumer petition also alleges that the original Essure clinical trials weren't conducted properly, and the device shouldn't have been approved in the first place, which the FDA is still investigating.In response to the rising controversy, and to learn more about what's really going on, the FDA asked Bayer (the device manufacturer) to perform what's called a " postmarket surveillance study. " But it's not clear how long the company will be studying people who've received the device. Also, Bayer will have to include both a boxed safety warning — the strongest type — and a detailed decision checklist designed to guide patients when making a choice about Essure."I think [the FDA's] reaction is appropriate," Jon I. Einarsson , MD, MPH, of Brigham and Women's Hospital tells Refinery29. "There has been increasing concern about the role of Essure in causing complications in patients, but it’s also not completely clear how common this is." It's also not totally understood why some patients might have complications while others don't. "That's why the postmarket study is warranted," he says."Patient safety and appropriate use of Essure are our greatest priorities," said Dario Mirski, MD, senior vice president and head of medical affairs Americas at Bayer in a statement . "A woman's decision to choose a birth control method is a very important and personal one, and Bayer is committed to providing physicians with resources, tools, and information to help them counsel women about Essure."Although it's not common for serious safety warnings to be added this late in the game, Dr. Einarsson points to a few other recent cases in gynecology. For instance, the FDA recently reclassified transvaginal mesh as a "high-risk" device due to serious complications. Unlike taking a medication, "a device is dependent on the surgeon that's using it," he says. During clinical trials, those surgeons are usually specialists with experience that, when a device is released to the world, the average surgeon actually implanting it might not have. Therefore we might see problems that weren't accounted for in trials. And Dr. Einarsson says that implants, especially those designed to be permanent, may show more problems because there's simply a longer timeline for issues to show up.And when it comes to the decision checklist, one thing patients may not necessarily have been aware of previously is that removing the device requires surgery, Dr. Einarsson explains. That might take the form of a hysterectomy, in which the uterus and fallopian tubes are removed, but the ovaries and hormones remain (so a patient doesn't go into an early menopause). The other option is to just remove the fallopian tubes, but because the device extends along the tubes into the uterus, Dr. Einarsson says a surgeon still has to be "fairly aggressive" when removing Essure in this way. After all, it's designed to be permanent.For their part, Essure Problems , a Facebook group (turned patient advocacy group) made up of women who believe they have experienced issues with their devices, has issued a press release saying they are "outraged" that Essure is still on the market at all after the FDA's announcement.