Hormonal birth control can negatively affect metabolic health and contribute to weight gain. Some types are more likely to do so than others.
Birth control replaces natural hormones with “hormone-like” medications
The main problem with hormonal birth control is that most types switch off estradiol and progesterone and replace them with synthetic substitutes. And while the ovarian hormones estradiol and progesterone are good for metabolic health, their replacements are not.
- On combined estrogen methods of birth control (pills, patches, rings), the ovaries produce almost no estradiol or progesterone. Those beneficial hormones are replaced by ethinylestradiol (a synthetic estrogen) and a progestin.
💡 Tip: Keep reading for the metabolic effects of ethinylestradiol and progestins.
- On the Depo-Provera injection, the ovaries produce no estradiol or progesterone. They’re replaced by the progestin medroxyprogesterone, one of the most weight-gain-promoting progestins.
- Progestin-only methods (implants, mini-pills) allow the ovaries to produce some estradiol but no progesterone. Progesterone is replaced by a progestin such as norethindrone, levonorgestrel, etonogestrel, or drospirenone. Check the label to see which one you’re taking.
- Hormonal IUDs (levonorgestrel-releasing IUDs) allow the ovaries to make both estradiol and progesterone (which is good!). However, levonorgestrel can directly cause weight gain because it’s androgenic.
💡 Tip: Androgenic progestins like levonorgestrel can increase visceral fat and reduce insulin sensitivity.
Metabolic effects of synthetic estrogen and progestins
Ethinylestradiol (synthetic estrogen)
Ovarian estradiol benefits metabolic health by promoting muscle growth and improving insulin sensitivity. Conversely, ethinylestradiol (the synthetic estrogen in birth control) can reduce muscle mass and impair insulin sensitivity. On the plus side (for metabolic health), ethinylestradiol lowers androgens, which can help to promote visceral fat loss.
Progestins and their effect on metabolic health and weight
The impact of progestins on metabolism depends on how androgenic (testosterone-like) they are:
Non-androgenic or anti-androgenic progestins (drospirenone, cyproterone acetate) can improve insulin sensitivity and reduce visceral fat. However, stopping them can induce insulin resistance and weight gain. Also, anti-androgenic progestins can have other side effects, such as anxiety and depression.
Androgenic progestins (levonorgestrel, norethindrone, etonogestrel, desogestrel, norgestrel, norgestimate, and medroxyprogesterone) impair insulin sensitivity and promote visceral 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) as a progestin-only pill, implant, injection, or IUD.
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? Share your experience.
