Does Birth Control Cause Weight Gain?

Can hormonal birth control cause weight gain or impair metabolic health? If so, which types are more likely to do so?

The first thing to understand is that the ovarian hormones estradiol and progesterone tend to promote subcutaneous fat but reduce visceral fat, which is good because visceral fat is the bad fat tied to insulin resistance or metabolic dysfunction. The second thing is that hormonal birth control mostly switches off estradiol and progesterone.

Birth control switches off ovarian hormones and replaces them with “hormone-like” medications

With most types of hormonal birth control, estradiol and progesterone are switched off and replaced with ethinylestradiol and a progestin. Here’s a little more detail:

• On a combined estrogen-progestin method like the pill, patch, or ring, the ovaries make almost no estradiol or progesterone. In place of real hormones, those methods provide ethinylestradiol (synthetic estrogen) plus progestin.

💡 Tip: Keep reading for the metabolic effects of ethinylestradiol and different progestins.

• On the Depo-ProveraⓇ injection, the ovaries make no estradiol or progesterone. Instead, the injection provides the progestin medroxyprogesterone, which can cause unstoppable weight gain; see below.
• On a progestin implant or progestin-only pill (sometimes called a “progesterone-only” pill despite not being progesterone), the ovaries make some estradiol but no progesterone. Instead, the methods provide a progestin such as norethindrone (norethisterone), levonorgestrel, etonogestrel, or drospirenone. Read the label to see which one you’re taking.
• Finally, on a hormonal IUD (which delivers the progestin levonorgestrel directly into the uterus), the ovaries can still make estradiol and progesterone. But, of course, a low level of levonorgestrel is also present throughout the body, including in the brain. As discussed below, androgenic progestins like levonorgestrel can increase visceral fat and cause abdominal weight gain.

The metabolic effects of synthetic estrogen and progestins

The synthetic estrogen of birth control (ethinylestradiol) can cause fluid retention and possibly reduce muscle. It may also impair insulin sensitivity, making it quite different from estradiol (the natural estrogen from the ovaries), which improves insulin sensitivity. So, ethinylestradiol is not as good for metabolic health as natural estradiol, but even ethinylestradiol can have the benefit of reducing androgens (see below).

The progestins of birth control can promote weight gain or weight loss, depending on the specific progestin and how androgenic or testosterone-like it is.

• Non-androgenic or anti-androgenic progestins like drospirenone and cyproterone acetate generally improve insulin sensitivity and reduce visceral fat, which is good. Unfortunately, coming off them can cause rebound insulin resistance and weight gain.
• Androgenic (testosterone-like) progestins like levonorgestrel, norethindrone (norethisterone), etonogestrel, desogestrel, norgestrel, norgestimate, and medroxyprogesterone can impair insulin sensitivity and increase visceral fat (also called abdominal or android fat). That’s because, in women, androgen or testosterone excess can cause or drive insulin resistance. And insulin resistance can cause weight gain.

💡 Tip: According to some research, medroxyprogesterone (Depo-ProveraⓇ injection) can cause “unstoppable weight gain,” which is weight gain that doesn’t plateau or level out.

💡 Tip: Androgenic progestins are more likely to promote weight gain (and other androgen side effects) when they’re taken on their own (without estrogen) in progestin-only methods such as implants, IUDs, or progestin-only pills. 

💡 Tip: Finally, natural progesterone (oral micronized progesterone) is anti-androgenic, so generally promotes good metabolic health despite increasing appetite and somewhat reducing insulin sensitivity. 

For more, read:

• Metabolism Repair for Women
• How testosterone can cause weight gain in women
• Medications that cause weight gain
• 4 causes of androgen excess in women
• The downside to contraceptive implants and injections
• The pros and cons of hormonal IUDs

What has been your experience with hormonal birth control and weight? Chime into the comments.