Weight gain is one of the most common concerns when starting birth control. In past decades, hormonal birth control may have caused some people to gain weight because it contained significantly higher amounts of estrogen and progesterone. However, this is not the case with most current combination hormonal birth control. A 2016 Cochrane review of 22 previous studies found little or no evidence of weight gain. Even among studies that did show slight increases in weight, the average weight gain was only 4.4 pounds. SOURCE: Medical News Today, 2023