The market taxonomy for Targeting Peptides also distinguishes several peptide classes that determine formulation complexity and cost structure. Cell‑penetrating peptides (CPPs) represent the largest subtype, enabling translocation across cellular membranes and accounting for roughly 40 % of peptide‑based platforms; their broad utility across indications inflates both R&D spend and unit price. Homing peptides, which bind selectively to disease‑specific surface markers, contribute about 30 % of the market and are critical in oncology and neurology where receptor fidelity drives clinical success. Affinity‑optimized peptides, engineered through iterative phage‑display cycles, hold a 15 % share and are valued for their high binding constants, reducing dosing frequency. Stimuli‑responsive peptides, designed to release cargo under pH or enzymatic triggers, occupy 10 % of the market, reflecting niche adoption in targeted drug‑release systems. Finally, bifunctional or dual‑targeting peptides, combining two distinct ligands, make up the remaining 5 %, supporting emerging combination‑therapy strategies. Each type’s proportion mirrors its technical maturity and the incremental value it adds to the overall Targeting Peptides market.