Small molecule
A small molecule drug is a medicine made of a small, simple chemical, like many everyday pills. Small molecules are often easy to swallow and can slip into cells. Peptides and proteins are larger and work differently.
For experts
Small-molecule drugs are low-molecular-weight compounds that are generally cheaper to make than peptides or biologics, can often be given orally and can cross cell membranes to reach intracellular targets. Their small size can make it harder to block large protein-protein interaction surfaces, an area where peptides and biologics can be advantageous.
Sources (1)
- 01Therapeutic peptides: current applications and future directionsSignal Transduction and Targeted Therapy (PubMed Central, NCBI/NLM) · 2022-02-14 · accessed 2026-09-29