Thyrotropin-Releasing Hormone (TRH) Free Acid (TRH-OH) causes a variety of thyroidal and non-thyroidal effects the best known being the feedback regulation of thyroid hormone levels.

Ac-KQKLR-AMC (Cathepsin S substrate) is a biological active peptide. (Cathepsins are a class of globular lysosomal proteases, playing a vital role in mammalian cellular turnover. They degrade polypeptides and are distinguished by their substrate specificities. Cathepsin S is a cysteine proteinase involved in the pathogenesis of autoimmune diseases, atherosclerosis, cancer, obesity and related diseases.This peptide is a cathepsin S substrate fluorescently labeled with AMC (Ex/Em=354 nm/442 nm). It can be used to measure cathepsin S activity.)

Donor of choline in biosynthesis of choline-containing phosphoglycerides.