Low-Level Plastic Chemical DEHP Disrupts Female Hormones and Reproductive Health

Recent research from the Institute of Environmental Medicine at Karolinska Institutet has shed light on the reproductive risks posed by the common plastic additive di(2-ethylhexyl) phthalate (DEHP). Published in Toxicological Sciences, the study indicates that even at low exposure levels, DEHP can significantly affect female hormone regulation and fertility-related parameters. The investigation involved exposing female mice to varying doses of DEHP and analyzing the impact on reproductive functions.

Key findings reveal that critical reproductive processes—such as hormone balance, ovarian follicle development, and progesterone levels—are particularly vulnerable to DEHP. These effects manifested at doses lower than those traditionally used in chemical risk assessments, highlighting a potential underestimation of health risks for women. The influence on ovarian follicle counts and hormonal levels was dose-dependent and more sensitive compared to other indicators like body weight or estrous cycle regularity.

Endocrine-disrupting chemicals like DEHP are known for their capacity to interfere with hormone systems, impacting male reproductive health as well. However, this new evidence emphasizes that female reproductive health is equally, if not more, susceptible. Current safety guidelines often overlook women-specific effects due to limited knowledge, a gap this study aims to address.

Using advanced modeling techniques, researchers analyzed data from multiple animal studies, demonstrating that estrogen-related endpoints are highly sensitive to DEHP exposure. Despite this, existing regulatory tests often exclude such parameters, risking the omission of significant reproductive impacts. The European Chemicals Agency’s risk assessments for DEHP, primarily based on male data, may thus be insufficient for safeguarding female fertility.

Lead researcher Antero Vieira Silva emphasizes the need for revised safety standards that consider female reproductive vulnerabilities. Pauliina Damdimopoulou underlines the importance of integrating female-specific effects into risk evaluations to better protect reproductive health.

This research highlights a significant knowledge gap surrounding chemical impacts on female fertility and advocates for regulatory updates. The findings suggest that chemicals like DEHP and other phthalates could pose greater reproductive risks for women than currently acknowledged, urging policymakers to reconsider existing safety thresholds.

For further details, the full study is available in Toxicological Sciences (2025), DOI: 10.1093/toxsci/kfaf052. The study urges improved testing protocols to ensure comprehensive protection of female reproductive health against chemical exposures.