A Narrative Review on the Influence of Electromagnetic Fields Below 100 kHz on the Endocrine System

Background: Extremely low-frequency electromagnetic fields (ELF-EMFs), generated mainly by power infrastructure and household devices, have raised scientific interest due to their potential impact on the endocrine system. Animal research consistently shows effects on melatonin secretion, stress hormone levels, thyroid activity, and reproductive function—largely mediated by oxidative stress and calcium ion imbalance. In contrast, human studies remain inconsistent, often hindered by methodological limitations and insufficient exposure characterization. Objective: This review synthesizes experimental and epidemiological studies examining ELF-EMF exposure (≤100 kHz) and its influence on hormonal regulation. Methods: A bibliometric analysis highlights focused interest on specific endocrine targets, particularly the pineal gland. Importantly, many experimental studies use field strengths above those found near high-voltage power lines, limiting direct applicability. Conclusions: While a definitive causal link has not been established, the widespread exposure justifies precautionary considerations. There are several key research gaps (of whom many are identified by this review); the topic of ELF EMF effect on endocrine system calls for more rigorous, long-term human studies with accurate exposure assessment.