Ghrelin (active) calibrator was developed for use as an assay calibrator for MSD U-PLEX assays that measure Ghrelin (active). Ghrelin (octanoyl-Ser3) was synthetically produced. The utility of this product has not been evaluated in other applications. The amount of each analyte is provided in the lot-specific certificates of analysis. There are instructions on using this calibrator in various U-PLEX Metabolic Group 1 Product Inserts.