A recent study presented at ENDO 2024 showed that rats given synthetic estrogens commonly found in contraceptive pills exhibited greater signs of anxiety compared to rats given natural estrogens. The study conducted by Abigail Hegwood, MS, aimed to investigate the differences between the two types of estrogens in terms of behavioral side effects. Three groups of female rats were given either a synthetic estrogen with progestin, a natural estrogen with progestin, or a control for 28 days. The results showed that rats given synthetic estrogen exhibited higher levels of anxiety-like behaviors during maze tests.
One of the key findings of the study was the impact of synthetic estrogens on hormone levels. Both types of estrogens reduced circulating testosterone levels, but the synthetic estrogen group had significantly lower levels of estradiol in their blood serum. This could potentially affect anxiety-related behaviors and spatial memory in the rats. The synthetic estrogen used in most contraceptive pills, ethinyl estradiol, was found to increase hormone-binding globulin, which in turn affects the availability of steroid hormones in the body, including the brain.
Alesia Prakapenka, PhD, the supervisor of the study, highlighted the potential consequences of using synthetic estrogens in hormonal contraceptives. She pointed out that the feedback loop between the hypothalamus, pituitary, and gonads could be disrupted by these synthetic hormones, leading to changes in hormone levels and behavioral responses. Additionally, the study revealed that naturally-produced estrogen levels were undetectable in many rats given ethinyl estradiol, raising concerns about the long-term effects of these hormones on the body.
The lack of focus on the behavioral effects of hormonal contraceptives is a concerning issue that needs to be addressed. Prakapenka emphasized the importance of considering individual differences in hormonal contraception and tailoring birth control options to meet the specific needs of women. She suggested that strategies used in menopausal hormone therapy could be applied to contraceptive use as well, in order to minimize side effects and improve overall health outcomes for women.
Jonathan Schaffir, MD, provided insight into the potential impact of hormonal contraceptives on mood and behavior. While acknowledging that exogenous hormones can influence mood to some extent, he also cautioned that the influence of oral contraceptives is typically small. Schaffir stressed the importance of examining the components of medications, especially hormones, to ensure the fewest side effects and the best physiological response. He also highlighted the need for developing new medications with better efficacy and fewer side effects.
The study on the behavioral effects of synthetic estrogens in contraceptives sheds light on the potential risks associated with these medications. The findings suggest that synthetic hormones may have a significant impact on anxiety-like behaviors and hormone levels in the body. Moving forward, more research is needed to better understand the long-term effects of synthetic estrogens on women’s health and to develop safer and more effective contraceptive options.