Abstract

Calabrese and Baldwin formalise hormesis as a biphasic dose-response — low doses stimulate, high doses inhibit — with adaptive and evolutionary significance beyond linear toxicology models.

Calabrese, E. J., & Baldwin, L. A. (2002). Defining hormesis. Human & Experimental Toxicology, 21(2), 91–97. DOI

Key findings

  • Biphasic definition — Hormesis requires stimulation at low dose and inhibition at high dose on the same endpoint.
  • Adaptive frame — Low-dose responses often reflect overcompensation after initial disruption — not noise.
  • Field boundary — Distinguishes hormesis from U-shaped curves without demonstrated low-dose benefit mechanism.

Application

When sizing a progressive exposure rep, treat the dose as bounded — enough signal to adapt, not enough to harm. Pair Hormesis · Mithridatisation.