Title: Synthetic Estrogens in Birth Control Linked to Anxiety in Rat Study
In a recent study, researchers discovered that synthetic estrogens, like ethinyl estradiol, used in most combined hormonal contraceptive pills, were linked to increased anxiety-like behaviors in rats compared to natural estrogens. This finding was presented at the Endocrine Society’s annual meeting, ENDO 2024, in Boston, MA.
The researchers used two types of estrogen in the study - a synthetic one, ethinyl estradiol, and a natural one, estradiol valerate. Rats were given these hormones in combination with dienogest, a progestin, for 28 days. After testing the rats’ spatial awareness and anxiety in a maze task, the researchers found that rats given synthetic estrogens showed altered responses in the task, indicative of anxiety-like behaviors.
While both types of estrogen reduced circulating testosterone levels in the rats, the authors suggest that the effect of synthetic estrogens on the brain might be responsible for the increased anxiety-like behaviors. The researchers propose that the higher effect of synthetic estrogens on hormone-binding globulin can make steroid hormones less available for use by the body and the brain, leading to greater effects on behaviors.
The findings could have implications for hormonal contraceptives, as they suggest that natural estrogens might be associated with fewer behavioral side effects. However, it's essential to conduct more research in humans to confirm these findings and explore the potential benefits of tailored hormonal contraception options.
The study's findings may raise concerns among women using combined hormonal contraceptives, as synthetic estrogens were linked to heightened anxiety-like behaviors. Furthermore, future research should focus on investigating if natural estrogens could alleviate these anxiety symptoms in women.
