Phenylmethanesulfonyl fluoride (PMSF (Phenylmethylsulfonyl fluoride)) is an enzyme inhibitor that inactivates IRC-50 arvin, subtilisin, and the fatty acid synthetase complex.

Aloxistatin (E64d) is an inhibitor of cysteine protease with blood platelet aggregation inhibiting activity. Aloxistatin is an irreversible, membrane-permeable inhibitor of lysosomal and cytosolic cysteine proteases with the ability to inhibit calpain activity in intact platelets.

E-64 (Proteinase inhibitor E 64) is an irreversible and specific inhibitor of cysteine proteases, exhibiting an IC50 of 9 nM for papain.

KGP94 is an inhibitor of cysteine protease Cathepsin L(CTSL).

2-Cyanopyrimidine (m-Hydroxyphenylpropionic acid) is inhibitor of cathepsin K(IC50 : 170 nM)

Esomeprazole is the S-isomer of omeprazole, inhibits the lysosomal cysteine protease legumain to prevent cancer metastasis. Esomeprazole is a proton pump inhibitors (PPI).

Z-Lys-OH is a competitive inhibitor of papain, a lysine derivative.

Leupeptin hemisulfate is a protease inhibitor with cell membrane-permeable, reversible, competitive, and oral activities. Leupeptin hemisulfate inhibits the activity of Cathepsin B, Cathepsin H, and Cathepsin L, and blocks fusion of amphipathic lysosomes. Leupeptin hemisulfate also has anti-inflammatory activity.