The scientific truth about weight gain and birth control.


Fear of gaining weight is a primary factor in how women choose which type of birth control to use-and that fear may be leading them to make riskier choices, says a new study published in Contraception.

Hormonal birth control has long gotten a bad rap for causing weight gain, leading many women to be leery of contraceptive options like the Pill, the patch, the ring, and other types that use synthetic female hormones to prevent pregnancy. Not only do women who worry about their weight avoid these methods, but this worry is one of the most commonly cited reasons why women stop using hormonal contraception altogether, said Cynthia H. Chuang, lead author and professor of medicine and public health sciences at Penn State, in a press release.

Women who reported being concerned about the weight-gain side effects of their birth control were more likely to choose nonhormonal options like condoms or the copper IUD; or riskier, less-effective methods like withdrawal and natural family planning; or to simply use no method at all. This was particularly true for women who were overweight or obese, Chuang added. Unfortunately, this fear may result in lifelong unintended consequences like, oh, a baby. (Here's how to find the best birth control for you.)

Good news: The link between weight gain and hormonal birth control is largely a myth, says Richard K. Krauss, M.D., chair of gynecology department at Aria Health. "There are no calories in birth control pills and studies comparing large groups of women who take and do not take birth control have shown no difference in weight gain," he explains. He's right: A 2014 meta-analysis of more than 50 birth control studies found no evidence that patches or pills cause weight gain or weight loss. (There is one exception to this rule, however: The Depo-Provera shot has been shown to cause a small amount of weight gain.)

But regardless of what the research says, the fact remains that this is an issue women do worry about, and it affects their choices for birth control. Enter the IUD. Long-acting reversible contraceptives (LARCs), like both the Paragard and Mirena IUDs, don't have the same weight-gain stigma as the Pill, making women who are very afraid of weight gain more likely to choose them-that's good news, as LARCs are one of the most effective and reliable methods on the market, Chuang said. So even though there's no scientific proof that the Pill causes weight gain, if this is something you're particularly worried about it, might be worth it to discuss LARCs or other reliable options with your doctor. (Related: 6 IUD Myths-Busted)

Bottom line? Don't worry so much about gaining weight from using birth control pills, or choose reliable no- or low-hormone options like an IUD. After all, there's nothing that will make you gain weight like a nine-month pregnancy.