non-monotonic dose-response curve
A complex relationship between the dose of a substance and its effect, such that instead of a certain response simply increasing or decreasing with dose, the curve may be for example "U" shaped
In food safety, a non-monotonic dose–response curve means that the effect of a substance does not steadily increase or decrease as the dose increases. Instead, low doses may cause effects that are different from, or even stronger than, those seen at higher doses. In other words, the relationship between dose and effect is not a simple “more dose = more effect” pattern.
EFSA considers non-monotonic dose–response relationships when assessing substances such as endocrine-active chemicals, where low doses can interfere with hormones. EFSA carefully reviews the scientific evidence, evaluates study quality and biological plausibility, and may use additional uncertainty factors or alternative assessment approaches when such effects are supported by robust data. This ensures that potential risks at low exposure levels are not overlooked and that consumer safety remains adequately protected.