biologic
A biologic is a medicine that is grown rather than chemically built. Instead of stitching atoms together in a flask the way you make a small-molecule pill, you coax living cells, such as engineered bacteria or animal cells in a steel tank, into manufacturing the drug for you. The product is typically a large, complex molecule like a protein or antibody that is far too big to assemble by ordinary chemistry.
Formally, a biologic is a therapeutic product derived from a living system, including proteins, antibodies, peptides, nucleic acids, and even whole cells. Because these molecules are large and three-dimensional, their exact folded shape is essential to their activity, and that shape depends on the living cells and conditions used to make them.
This biological origin is also the main drawback. Biologics are expensive to produce, sensitive to heat and handling, and almost always must be injected because they would be digested if swallowed. They also cannot be copied atom-for-atom the way a generic pill can, which is why near-copies are called biosimilars rather than generics.
Insulin and the antibody adalimumab are both biologics: large proteins produced in living cells and given by injection.
Two everyday biologics that cannot be made by ordinary chemical synthesis.
The contrast term is 'small molecule', a conventional drug made by chemical synthesis; biologics and small molecules are the two broad pillars of modern therapeutics.