EXECUTIVE SUMMARY

New research shows that oral contraceptive use does not affect people’s behavior, feelings, and gender self-concept, although it does appear to affect cognition.

  • Women who used oral contraceptives showed no differences in openness, conscientiousness, neuroticism, extroversion, and agreeableness.
  • Gender self-labels, such as how people appear, act, and view themselves, also were not affected by oral contraceptive use.
  • But people using oral contraceptives, depending on particular formulations, demonstrated better verbal working memory and spatial ability.

Millions of women use oral contraceptives (OCs) in the United States, but not enough is known about how these affect their behavior, feelings, and gender self-concept. However, there is some evidence of effects on cognition, research suggests.1,2

“From a basic science perspective, we wanted to use oral contraceptives as a natural experiment,” says study co-author Adriene M. Beltz, PhD, assistant professor of psychology, research assistant professor of data science, and 2020-2022 Jacobs Foundation research fellow at the University of Michigan. “Women are putting hormones into their body every day at doses we know, so we can use that information to determine if it impacts other aspects of their behavior and feelings. Informing women to whether cognition, actions, or behaviors are related to oral contraceptive use can allow them to be empowered in their decision as they choose to use oral contraceptives or not.”

Beltz and her co-investigator examined whether oral contraceptives affected gender self-concept, which their study described as a broad range of psychosocial constructs linked to individual and cultural perceptions of gender. These include being other-oriented and self-assertive.1

“We looked at gender self-labels, how you appear, how you act, and how you view yourself,” Beltz says. “[We thought] women may choose to use oral contraceptives differently, depending on how they see their gendered personality and how they label themselves in terms of masculinity and femininity.”

This was not about people who did not identify with their sex assigned at birth. “We only have women in the study who identified as cisgender women,” she says. “What we find is that there are no differences between women who do and don’t use oral contraceptives and these aspects of gendered personality qualities.”1

Beltz and her co-investigator found no difference between OC users and non-users in general personality traits, such as openness, conscientiousness, nervousness, and others, Beltz says.1,3 There also were no differences in personality factors of neuroticism, extroversion, and agreeableness.3

“Women who do or don’t use oral contraceptives did not differ in any of those personality features or factors,” she explains. “It didn’t matter whether the women were using oral contraceptives for therapy purposes or contraceptive purposes.”

Evidence suggests OCs affect some aspects of cognition, particularly related to verbal working memory.2

“I think the emerging story out of work from our lab is that there aren’t personality and gender self-concept differences between users, but there are some differences in cognition,” Beltz adds. “These are small effects, and some people might notice and some might not, but on average they seem to be there.”

Finding cognition differences with OC use is not shocking because scientists already knew that as ovarian hormones change throughout life, such as at menopause when the hormones decline, there are cognitive consequences.

“Women report feeling cognitively fuzzy, and one of the big things to drop is verbal working memory,” she says. “There certainly seems to be something about hormones affecting verbal working memory.”

It also is possible that some OCs affect spatial skills, depending on formulations. “The effects are small but have been consistent across several studies,” Beltz notes.

For instance, women who use OC might perform slightly better when recalling a grocery list than women who do not use oral contraceptives. Also, research shows that women using a monophasic oral contraceptive formulation, consisting of ethinyl estradiol and a second-generation progestin, show better spatial ability than naturally cycling women.2

“One of the takeaway messages is that we need to be aware of the pills and the different formulations,” Beltz says.

Reproductive health providers could ask women what is important to them and recommend a particular oral contraceptive based on their preferences.

“All oral contraceptives seem to have similar impacts as far as we can tell,” Beltz says. “But if there are some that heighten verbal working memory or maybe spatial skills, let’s know what those pills are and think about that when women want to decide which pill to use.”

More research is needed on this topic to help clinicians and women make these decisions. “Studies help us understand how hormones affect everyone, potentially, and also how to help women make the right choices and advocate for the right contraceptives,” Beltz says. “I think this is really important for us to understand.”

REFERENCES

  1. Nielson MG, Beltz AM. Oral contraceptive use is not related to gender self-concept. Psychoneuroendocrinology 2021;129:105271.
  2. Beltz AM, Hampson E, Berenbaum SA. Oral contraceptives and cognition: A role for ethinyl estradiol. Horm Behav 2015;74:209-217.
  3. Beltz AM, Loviska AM, Kelly D. No personality differences between oral contraceptive users and naturally cycling women: Implications for research on sex hormones. Psychoneuroendocrinology 2019;100:127-130.