Hirudin Hirudin Hirudin is a naturally occurring peptide in the salivary glands of blood-sucking leeches (such as "Hirudo medicinalis") that has a blood anticoagulant property. This is fundamental for the leeches’ alimentary habit of hematophagy, since it keeps the blood flowing after the initial phlebotomy performed by the worm on the host’s skin. During his years in Birmingham and Edinburgh, John Berry Haycraft had been actively engaged in research and published papers on the coagulation of blood, and in 1884, he discovered that the leech secreted a powerful anticoagulant, which he named hirudin, although it was not isolated until the 1950s,
Copper peptide GHK-Cu iron metabolism, oxygenation, neurotransmission, embryonic development and many other essential biological processes. Another function of copper is signaling – for example, stem cells require a certain level of copper in the media to start their differentiation into cells needed for repair. Thus, GHK-Cu’s ability to bind copper and to modulate its tissue level is a key factor determining its biological activity. Copper peptide GHK-Cu Copper peptide GHK-Cu is a naturally occurring copper complex of the tripeptide glycyl--histidyl--lysine. The tripeptide has strong affinity for copper(II) and was first isolated from human plasma. It can be found also in saliva and urine.