MTD is the acronym for "Maximum tolerated dose". In preclinical pharmaceutical research, MTD denotes an important toxicological fixed point in the determination of toxicity. MTD refers to the highest dose that causes signs of toxicity in animals without having a significant effect on the survival time of the animals during the respective test duration. An MTD is defined by physical changes, such as a 10% reduction in the physiological weight gain of an animal.
The MTD is used as a dose in chronic toxicity studies.