Estimating the no-observed-adverse-effect-level (NOAEL) of hormetic dose-response relationships in meta-data evaluations

The number of studies reporting hormetic responses is rapidly increasing, and quantitative evaluations are needed to improve the understanding of hormetic dose responses. However, there is no standardized methodology to estimate the no-observed-adverse-effect-level (NOAEL) of hormetic dose-response relationships developed using data mined from the published literature. Here, we propose a protocol that can be followed to estimate NOAEL, a process that is illustrated using a specific example. This protocol can be used for maintaining a mutual language (since NOAEL can be defined in different ways), permitting comparisons among different studies, and facilitating cumulative science.