horme-

1. The stimulating effect of a small dose of a substance that is toxic in larger doses.
2. The controversial hypothesis that very low doses of ionizing radiation may not be harmful and may even have beneficial effects.

A pollutant or toxin showing hormesis has the opposite effect in small doses than in large doses.

3. A process whereby organisms exposed to low levels of stress, or toxins, become more resistant to tougher challenges.
4. Etymology: from Hellenistic Greek hormesis, "rapid motion, eagerness". This term was coined in 1943.

The main characteristic of hormesis is the biphasic dose response, in which high doses of a substance are toxic but low doses are beneficial.

Although the potential of hormesis to prevent and to treat diseases is becoming clearer; it is necessary to identify hormetic agents, work out how they affect general health and specific diseases, and to look into their possible additive benefits.

Referring to a process in which high doses, or quantities, of a substance are toxic but low doses are thought to be beneficial.