Table I.

Comparison Between Peptides and Small Molecules

Small molecules

Peptides

• ∼80% drug market • Low cost • Permeable • Stable • Good oral bioavailability • Easier synthesis

• ∼2% drug market • High cost • Low permeability • Limited stability • Poor oral bioavailability • More challenging synthesis • Short half-life • Limited to extracellular targets • High binding affinity • Easier to identify • Excellent target specificity • Broad disease targets • Mechanism of action well understood • Low toxicity and immunogenicity • Low risk of drug–drug interaction potential • Lower impact from generics