Before a compound is synthesized, AI models can estimate what the body will do to it. These predictions are grouped under the label ADMET: absorption, distribution, metabolism, excretion, and toxicity.
Absorption asks how much of an oral dose crosses from the gut into the bloodstream. Distribution asks where the compound goes once in circulation — whether it reaches the tissue of interest or is largely bound to blood proteins. Metabolism asks how quickly liver enzymes chemically modify and deactivate it. Excretion asks how fast the body removes it. Toxicity asks whether the compound or its breakdown products harm cells, and whether it interferes with proteins such as the hERG ion channel, whose blockage is associated with dangerous heart-rhythm effects.
Each of these is predicted from the same input the model already uses for binding: the molecular structure. A trained model maps structural features — polarity, size, the presence of particular chemical groups — onto measured outcomes from thousands of compounds whose ADMET behavior was determined experimentally. The output is a panel of estimates attached to the structure, letting chemists discard compounds that are likely to fail on absorption or safety before spending weeks making them.