ACS Medicinal Chemistry Letters welcomes submissions of manuscripts discussing various aspects of medicinal chemistry. The journal publishes research covering a wide range of topics, including compound design and optimization, biological evaluation, drug delivery, imaging agents, and the pharmacology of both small and large bioactive molecules. Specific areas of interest include, but are not limited to: identification, synthesis, and optimization of lead bioactive molecules and drugs (small molecules and biologics); biological characterization of new molecular entities in the context of drug discovery; computational, cheminformatics, and structural studies for identification or confirmation; SAR analysis of bioactive molecules, ligands, and their targets; novel and improved methods, including radiobiochemistry, widely applied in medicinal chemistry; discovery techniques for bioactive molecules from synthetic and natural (plant and other) sources; mechanistic pharmacokinetic/pharmacodynamic studies; potential drug disposition and reactions aimed at enhancing drug design; and pharmacogenetics and pharmacogenomics research related to the translation of medicinal chemistry into clinical applications, including mechanistic drug metabolism and regulation of gene expression of metabolic enzymes.