Incorporating Hormesis Into Policy: Opportunities, Risks, and Governance Challenges

Public policy faces challenges when low and high exposures to the same stressor produce different, and sometimes opposite, biological effects. Hormesis challenges regulatory approaches based on linear assumptions, fixed thresholds, and population-average responses. Here, I develop a policy framework for examining its implications across environmental regulation, public health, medicine, agriculture, and antimicrobial resistance. Dose, timing, duration, recovery, vulnerability, endpoint, and exposure context are essential dimensions of policy evaluation, while controlled interventions differ from involuntary environmental exposures. Hormesis alone does not justify increased exposure or regulatory relaxation, although case-specific changes may be warranted by evidence of net benefit and acceptable risk. Its responsible incorporation can optimize precaution, improve regulatory responsiveness to biological complexity, and prevent low-dose stimulation from being misinterpreted as evidence of safety or benefit.