Hormonal contraceptives are frequently prescribed to young women not only to prevent pregnancies, but to “regulate” irregular menstrual cycles, ameliorate heavy and/or painful periods, clear up acne, and to manage symptoms of PCOS/PMOS such as excess hair growth. There are many known risks of hormonal contraceptives, but could those risks include changes to adolescent girls’ brain development, ultimately affecting their temperament and personality? Here’s what we know.
Effects on the brain and mental health: the risks of hormonal contraceptives we already knew about
Structural changes to the brain
In natural, regular menstrual cycles, the fluctuations of estrogen and progesterone help to maintain healthy emotional regulation. Through various mechanisms, hormonal contraceptives (HCs) have been shown to alter women’s emotional regulation and responses to stress.
The ventromedial prefrontal cortex, the part of the brain that’s responsible for decision-making, emotional regulation, and memory, works together with the parts of the brain that process fear. A 2023 study found that women using hormonal contraceptives had greater susceptibility to chronic anxiety and greater overall fearfulness because of a thinning of the tissue in the ventromedial prefrontal cortex [1]. The thickness of the vmPFC tissue correlates with one’s ability to handle generalized fear, mental and emotional resilience, and the ability to stay calm.
Studies on HCs have also identified “structural and functional changes in areas involved in affective and cognitive processing, such as the amygdala, hippocampus, prefrontal cortex and cingulate gyrus,” and found that “…suppression of endogenous hormones and/or the introduction of exogenous synthetic hormones during adolescence have the potential to impact hormone-mediated neurodevelopmental processes” [2].
Changes in behavior and mental health
Furthermore, women taking HCs are also at an increased risk of dying a violent death, which may indicate that HCs alter decision-making processes, and increase risk-taking behaviors [3]. Women taking HCs likewise have an increased risk for suicide, which may be due to the link between hormonal contraceptives and depression [4]. A study conducted on women from age 15-32 found that hormonal contraceptives were “positively associated with a first suicide attempt, as compared with never-users,” and the highest relative risks were experienced by adolescents [5]. Hormonal contraceptives can also lessen the amount of stage 3 sleep a woman experiences, which is the restorative stage of the sleep cycle.
Brain development during adolescence: the changes wrought by hormonal contraceptives that may impact personality development
Besides the aforementioned mental health implications, how might birth control pills change brain development, and therefore affect temperament and personality, in young girls? This is the question Dr. René Ecochard asks in a 2025 article published in The Linacre Quarterly, the journal of the Catholic Medical Association [6]. First, Dr. Ecochard examines what normally happens to the brain and body during adolescence.
Understanding adolescent development
Adolescence is the period where a child’s innate psychological and physiological traits, or temperament, which is the foundation on which personality develops, begin to cohere rapidly. The brain develops just as muscles develop through physical exercise.
As Dr. René Ecochard states “…men and women are born with different inclinations and aptitudes. These innate gifts develop to varying degrees depending on an individual’s culture, education, and free choices. Adolescence is a crucial time of hormonal-dependent brain development.”
The natural re-wiring of adolescent brains which prepares them for adulthood
Dr. Ecochard first describes how, during adolescence, boys and girls both undergo radical, sex-specific anatomical and functional changes in their brains, or a “re-wiring” that prepares them for adulthood, and, potentially, parenthood. During puberty, adolescent bodies develop both the physical and psychological skills required to pass on life—fertility and attractiveness to the opposite sex. Adolescence is also a time when children learn how to transition from living within their families to learning the skills needed to support themselves and their future families.
Dr. Ecochard first describes how, during adolescence, boys and girls both undergo radical, sex-specific anatomical and functional changes in their brains, or a “re-wiring” that prepares them for adulthood, and, potentially, parenthood.
Furthermore, around the last stage of adolescence, which occurs at approximately 20 years old, young adults gain the ability to more effectively discern due to the development of the prefrontal cortex, which communicates with the cerebral amygdala, where emotions are managed. This discernment allows young adults to more accurately analyze the practical and emotional aspects of a situation.
Empathy and decision-making
Two elements that develop during adolescence are empathy and decision-making. The female brain, specifically, is primarily wired for empathy, and has an innate aptitude for emotional empathy that is often developed in little girls from an early age. Women tend to absorb the suffering of others as if it was their own, and they respond more quickly than men, who often spend more time in systematic rational analysis of the situation.
Dr. Ecochard likewise explains how young girls are more likely to have the ability to read emotional states in another person’s eyes, the ability to use nonverbal language, and the ability to remember situational details. The quantity and action of vasopressin and oxytocin, the neurotransmitters involved in empathy, change according to the amount of sex hormones present in the body. In females, these neurotransmitters respond to estrogen, which is what makes it easier for women to perceive feelings in the eyes of others.
There are also four different aspects of decision-making that develop during adolescence, which include the role of emotions in decision-making, the role of risks, the role of intuition, and how boys and girls each take details into account.
Emotions
The cerebral amygdala, which is responsible for emotional management, transmits messages less to the decision-making centers in men than in women, and men are therefore less impacted by the emotional aspects of making a decision than women are.
Risk-taking
When it comes to risk-taking, women tend to be more averse to risk-taking than men; testosterone in men tends to encourage risk-taking, and estrogen tends to encourage risk-avoidance in women.
Intuition
Girls and boys also process information in their brains differently during adolescence. In girls, there is a balance between information sharing in the right and left hemispheres of the brain, which indicates a balance between the rational and intuitive parts of the decision-making process.
Boys, however, “exhibit greater within-hemispheric connectivity” [7], which Dr. Ecochard asserts “is consistent with their greater coordination between what is perceived and what is done, leaving less room for intuition” in male decision-making.
Attention to details
Lastly, women tend to take details into account more when making decisions. Dr. Ecochard explains that women often memorize details, whereas men memorize the “whole picture.” Women are also more likely to consider all of the successive steps required to achieve a goal, as this information tends not to reach the decision-making centers of the cerebral amygdala in men.
When hormonal contraceptives are thrown into mix, they don’t simply “replace” natural hormones
The hormones that are naturally secreted during the menstrual cycle (chiefly estrogen and progesterone) occur in parallel with brain changes in girls. As Dr. Ecochard points out, “As hormone secretions are sex-specific, they will induce a specific brain development, specific to women or specific to men. Thus, a young girl’s natural hormones play an important part in the development of her brain during adolescence. The development of female psychology is therefore, to some extent at least, influenced by the girl’s hormones.” The crux of Dr. Ecochard’s theory that hormonal contraceptives may alter normal adolescent brain development hinges on the fact that the natural onset of female hormones during puberty—which alter the brain in sex-specific ways—differs markedly from the hormonal profile that is created through hormonal contraceptives.
The crux of Dr. Ecochard’s theory that hormonal contraceptives may alter normal adolescent brain development hinges on the fact that the natural onset of female hormones during puberty—which alter the brain in sex-specific ways—differs markedly from the hormonal profile that is created through hormonal contraceptives.
Before adolescent cycles regulate, estrogen naturally dominates
In the natural onset of an adolescent girl’s menstrual cycle, estrogen gradually increases and is the dominant hormone until progesterone production begins, gradually increasing in amount until the balance between the two hormones reaches adult levels. It is this natural, early estrogen dominance in puberty that causes the developmentally normal phenomenon of irregular early adolescent cycles.
Unfortunately, in the young adolescent girl, these irregular cycles are often “regulated” via hormonal birth control, sometimes before estrogen and progesterone can reach their adult balance and cycles can reach maturation. The synthetic hormones in an adolescent girl’s birth control suppress her body’s natural hormone production (including estrogen, progesterone, follicle-stimulating hormone, luteinizing hormone, and testosterone), and instead create a consistent, stable hormonal profile, which is markedly different from that which she would typically experience during puberty (which, to reiterate, is a period of estrogen dominance followed by the gradual introduction of higher progesterone production).
The impact of hormonal contraceptives on female personality
Why does any of this matter? As Dr. Ecochard points out, “given the importance of estrogen in brain maturation, it seems very important to consider this installation of cycles, with a predominance of estrogens, as likely to play a part in the construction of the female psyche. This is a serious reason for questioning the use of hormonal contraceptives during adolescence.”
In studies that analyze the abilities of women with or without hormonal contraceptives, it has been found that, while estrogen usually enhances memory, especially during the fertile (estrogenic) phase of their natural cycle, women on contraceptives were much better at remembering locations (a trait typically seen in men). Also, women taking HCs are better at seeing the “big picture,” and worse at remembering details (which, again, are typically more masculine characteristics). Dr. Echochard posits that the loss of the ability to consider all of the successive steps required to achieve a goal, along with the ability to memorize details, may result in the reduced risk aversion we see in women on hormonal contraceptives.
Furthermore, women generally have a stronger aptitude for verbal, such as language, and nonverbal language, such as eye contact (important for perceiving emotions in others) and facial recognition, specifically during the fertile phase of their cycles. HCs can alter word management skills and the activity of brain areas involved in recognizing faces.
As Dr. Ecochard writes, “These skills contribute to feminine and maternal empathy and are particularly relevant to the female personality.” If the skills and aptitudes typically associated with the female personality (which are thought to elicit feminine and maternal emotional understanding and empathy) are being suppressed or altered by the introduction of HCs, how might this impact girls and young women individually, and society as a whole?
If the skills and aptitudes typically associated with the female personality (which are thought to elicit feminine and maternal emotional understanding and empathy) are being suppressed or altered by the introduction of HCs, how might this impact girls and young women individually, and society as a whole?
A solution to menstrual cycle issues that doesn’t alter female adolescent brain development
Instead of turning to hormonal contraceptives for the treatment of PCOS/PMOS, endometriosis, acne, and the ailments that come along with these conditions such as heavy, painful periods and irregular cycles, female sufferers can find true healing by thoroughly tracking their cycles via a Fertility Awareness Methods, and finding care from a Restorative Reproductive Medicine (RRM)-trained healthcare professional. These avenues help restore overall health and get to the root of these issues, instead of simply masking the issue and causing more harm than good to the bodies of girls and women.
Finally, better puberty and body literacy education is needed on a societal scale, so that very early adolescent cycle irregularities can be recognized for what they often are: a normal part of female adolescent development.
References
[1] Brouillard A, Davignon L-M, Turcotte A-M and Marin M-F (2023) Morphologic alterations of the fear circuitry: the role of sex hormones and oral contraceptives. Front. Endocrinol. 14:1228504. doi: 10.3389/fendo.2023.1228504
[2] Brønnick MK, Økland I, Graugaard C and Brønnick KK (2020) The Effects of Hormonal Contraceptives on the Brain: A Systematic Review of Neuroimaging Studies. Front. Psychol. 11:556577. doi: 10.3389/fpsyg.2020.556577
[3] Hannaford P C, Iversen L, Macfarlane T V, Elliott A M, Angus V, Lee A J et al. Mortality among contraceptive pill users: cohort evidence from Royal College of General Practitioners’ Oral Contraception Study BMJ 2010; 340 :c927 doi:10.1136/bmj.c927
[4] Anderl C, de Wit AE, Giltay EJ, Oldehinkel AJ, Chen FS. Association between adolescent oral contraceptive use and future major depressive disorder: a prospective cohort study. J Child Psychol Psychiatry. 2022 Mar;63(3):333-341. doi: 10.1111/jcpp.13476. Epub 2021 Jul 12. PMID: 34254301; PMCID: PMC9291927.
[5] Skovlund, C. W., Mørch, L. S., Kessing, L. V., Lange, T., & Lidegaard, Ø. (2018). Association of Hormonal Contraception With Suicide Attempts and Suicides. American Journal of Psychiatry, 175(4), 336–342. https://doi.org/10.1176/appi.ajp.2017.17060616 (Original work published April 1, 2018)
[6] Ecochard, R. (2026). Could the contraceptive pill pose a risk to brain development in young girls? The Linacre Quarterly, 93(2), 189–200. https://doi.org/10.1177/00243639251389448
[7] Ingalhalikar, M., A. Smith, D. Parker, T.D. Satterthwaite, M.A. Elliott, K. Ruparel, H. Hakonarson, R.E. Gur, R.C. Gur, & R. Verma, Sex differences in the structural connectome of the human brain, Proc. Natl. Acad. Sci. U.S.A. 111 (2) 823-828, https://doi.org/10.1073/pnas.1316909110 (2014).
