Cyclo (His-Pro) was shown, upon administration, to upregulate heat shock proteins 70 and 27 (that’s HSP70 and HSP27). It is derived from thyrotropin-releasing hormone, which is what stimulates the thyroid to release thyroid stimulating hormone. And when thyrotropin-releasing hormone loses its pyroglutamate amino acid, it forms (His-Pro). Cyclo (His-Pro) is also present in some common foods, with dried shrimp having the highest concentrations.