Drug transporters are specialized proteins found in cell membranes that facilitate the movement of drugs and other substances into and out of cells. They play a crucial role in determining how effectively a medication works by influencing its absorption, distribution, metabolism, and excretion. These transporters can be categorized into two main types: solute carrier (SLC) transporters, which generally help in the uptake of drugs, and ATP-binding cassette (ABC) transporters, which often assist in the efflux or removal of drugs from cells. Understanding these transporters is essential for optimizing drug therapy and minimizing side effects.