The University of Kentucky's Drug Quality Task Force (DQTF) conducted a study to perform consumer-level quality assurance screening of vasopressin injections used in their healthcare pharmacies. The primary objective was to identify potential quality defects by examining intralot and interlot variability using Raman spectrometry and statistical analyses. Raman spectra were collected noninvasively and nondestructively from vasopressin vials (n=51) using a Thermo Scientific Smartraman DXR3 Analyzer. Data processing techniques, including smoothing with cubic splines and Multiplicative Scatter Correction (MSC), were applied to prepare the spectra for analysis. Statistical analyses employed included the Bootstrap Error-Adjusted Single-sample Technique (BEST), Principal Component Analysis (PCA), and subcluster detection to assess variability and detect unusual samples. The study revealed significant intralot and interlot variability in the vasopressin samples. Analysis of Raman spectral graphs from vials in lot 22040L1C0 showed multiple subgroups within a single lot, indicating variability in chemical composition. Examination of the entire spectral library, which included vials from two different lot numbers, revealed four distinct groups that did not correspond to lot numbers. A subcluster detection test confirmed the presence of at least two distinct chemical compositions in samples from both lots, rejecting the null hypothesis that the groups have the same scale and location. While these spectrometric results do not conclusively prove an excess level of impurities or adulteration, they suggest that the manufacturing process may have been operating outside of a state of process control. These findings highlight the need for further investigation into potential process control issues to ensure consistent manufacturing processes and maintain drug quality and efficacy.