Summary: A large, first-of-its-kind longitudinal study from Michigan State University links combined oral contraceptives (COCs) that contain synthetic estrogen and progestin with short-term increases in binge-related symptoms, specifically emotional eating. Tracking 422 women across 49 consecutive days, researchers compared behavior during active hormone pill weeks to placebo (inactive pill) weeks and found a consistent rise in emotional eating when participants were taking active hormone pills. The increase was concentrated in women with existing risk factors for binge eating, and daily self-monitoring of eating behavior substantially reduced these hormone-associated spikes.
This research offers new evidence that synthetic hormones in commonly used combined oral contraceptives can alter eating-related behavior for some women. It also highlights a simple, effective intervention—daily self-monitoring—that can blunt these changes and supports the move toward more personalized contraceptive counseling in women’s health.
Key Facts
- Synthetic hormone effect: Active pills in monophasic combined oral contraceptives with synthetic estrogen and progestin were associated with higher levels of emotional eating compared with inactive (placebo) pills.
- Large, longitudinal design: This is the first large-scale daily tracking study to examine how oral contraceptive cycles relate to short-term changes in binge-related eating behavior.
- Sample and duration: 422 women from the Michigan State University Twin Registry reported daily for 49 days, allowing within-person comparisons between active and inactive pill phases.
- Targeted vulnerability: Increased emotional eating was not universal. Elevated risk clustered among women with prior clinical histories or other preexisting vulnerabilities to disordered eating.
- Self-monitoring works: Daily reporting of eating and mood significantly reduced binge-eating episodes, even during active hormone pill weeks, suggesting an accessible behavioral tool for risk mitigation.
- Implications for care: The authors recommend educating clinicians about these neurobehavioral effects so contraceptive choices can be tailored to individual risk profiles.
Study participants were current users of monophasic combined oral contraceptives—formulations that include a sequence of active hormone pills followed by inactive placebo pills. That standard pill schedule created a natural within-person comparison: the same woman’s behavior while taking active hormone pills versus while taking inactive pills.
Across 49 consecutive days of daily self-reports, the primary outcome was emotional eating, defined here as episodes of overeating linked to negative emotions. The main analysis compared emotional eating scores within women between active and inactive pill days and controlled for negative affect. The pattern of increased emotional eating on active pill days repeated across two pill cycles and was also observed among the subgroup of women with clinically defined binge-eating episodes.
Lead author Kelly Klump, MSU Research Foundation Distinguished Professor in the Department of Psychology, noted that these findings do not imply that combined oral contraceptives are unsafe for most users. “COCs remain effective and appropriate for many women,” Klump said. “However, our data suggest that synthetic hormones can act as a targeted trigger for emotional eating in women who already have vulnerability due to genetic, biological, or psychological factors.”
Importantly, the study found no meaningful changes in weight preoccupation across pill types, indicating a specific effect on emotional eating rather than a broad shift in body image concerns. Analyses showed that changes in negative affect did not fully explain the rise in emotional eating, pointing toward a hormone-driven influence on appetite and reward circuits rather than a simple mood effect.
Why hormones can influence emotional eating
Natural ovarian hormones such as estrogen and progesterone affect neural systems that regulate reward, mood, and appetite, including serotonin and dopamine pathways. When synthetic hormones from combined oral contraceptives override natural fluctuations, they can alter those circuits. In individuals with preexisting vulnerabilities, that shift may make emotional eating more likely as a coping response to disrupted appetite regulation.
Self-monitoring as a practical intervention
Daily self-monitoring—recording food intake and emotional state—acted like a brief behavioral intervention in this study. Rooted in cognitive behavioral therapy principles, self-monitoring interrupts impulsive eating by creating a moment of awareness and activating executive control. Participants who reported daily experienced fewer binge episodes even during active hormone periods, suggesting that simple tracking could be a scalable support for at-risk women using hormonal contraception.
A: No. The study found increased emotional eating primarily among women who already had risk factors for binge eating. Combined oral contraceptives are safe for many women; the effect appears to be a specific trigger in a subset of users rather than a universal cause of eating disorders.
A: Logging emotions and food intake interrupts automatic behaviors and increases awareness. That pause helps the brain’s executive control systems to engage, making it easier to resist impulsive binge episodes triggered by hormone-related changes.
A: Clinicians should consider a woman’s history of disordered eating and other vulnerabilities when discussing contraceptive options. Educating patients about potential mood and appetite effects and offering simple tools like daily self-monitoring may help personalize care and reduce risk.
Editorial Notes:
- Edited by a Neuroscience News editor.
- Journal paper reviewed in full by the editorial team.
- Additional context and clarifications added by staff for accuracy and readability.
About this research on neuropharmacology and binge eating
Author: Jack Harrison
Source: Michigan State University
Contact: Jack Harrison – Michigan State University
Image credit: Neuroscience News
Original Research: Combined Oral Contraceptive Use and Binge Eating, by Klump KL et al., published in JAMA Network Open. DOI: 10.1001/jamanetworkopen.2026.19047. Open access.
Abstract (condensed)
Importance: Endogenous ovarian hormones influence binge-eating risk, and most women use combined oral contraceptives that mimic hormone patterns associated with elevated risk. The effects of COCs on binge eating were previously unclear.
Objective: To test whether active versus inactive COC pills are associated with within-person changes in binge-related behavior, measured as emotional eating.
Design, Setting, and Participants: Daily surveys collected over 49 consecutive days from 422 women in the Michigan State University Twin Registry who used monophasic combined oral contraceptives. Data were gathered from 2017 to 2024 and analyzed from April 2024 to November 2025.
Exposure: Pill type (active hormone pills vs inactive placebo pills).
Main Outcomes and Measures: Within-person changes in emotional eating between inactive and active pill days, controlling for negative affect. Secondary analyses examined weight preoccupation and a clinical subsample with binge-eating episodes.
Results: Significant within-person increases in emotional eating were found during active hormone pills versus inactive pills in the full sample across two cycles (cycle 1: β = 0.11, 95% CI 0.06–0.16; cycle 2: β = 0.07, 95% CI 0.04–0.10). Similar increases appeared in the subsample with clinically defined binge-eating episodes. No significant changes were observed for weight preoccupation.
Conclusions and Relevance: Active combined oral contraceptive pills were specifically associated with increased risk for emotional eating in some women. Future work should identify which women are most vulnerable to inform personalized contraceptive counseling and to explore alternatives that minimize impact on binge-related behaviors.