2. Your weight may change… or it may not
Going onto birth control introduces progestin in the body. The increased progestin prevents the body from releasing an egg, thereby preventing pregnancy. It also changes the womb lining so that a pregnancy cannot develop. Progestin thickens the mucus located at the cervix to stop sperm from entering. Progestin is produced in a laboratory and used in birth control. It has progesterone-like properties.
Raised progestin levels can result in a few pounds gained. Studies to determine how and why this happens are ongoing. It is believed that there is a link between increased progesterone levels and increased appetite, especially when the pill contains no estrogen. If you are concerned about weight gain from being on birth control, be selective about which one you use. If the pill you’re taking contains estrogen as well, weight gain may be caused by water retention. Women who have used the birth control injection Depo-Provera usually report a 10-pound weight gain within about 18 months.
Weight gain can be mitigated depending on the class of progesterone present in your birth control. There are three main classes of progesterone called progestational, estrogenic, and androgenic. When birth control pills were first invented, they contained a lot of androgenic progesterone which has been linked to weight gain. Today’s versions of the pill contain far less androgenic progesterone. Norgestimate, desogestrel, and drospirenone are the three progestins that are the least androgenic. So, if you’re concerned about weight gain, try to use a pill that contains these.
You may gain weight when you start using birth control. But its pregnancy-preventive properties far outweigh a few extra pounds that can be lost with a good exercise program and diet.