Purpose <p>To evaluate the effectiveness of subcutaneous glucagon in reducing motion artifact during prostate MRI through intraindividual comparison.</p> Methods <p>At our institution patients undergoing a clinical prostate MRI exam receive 1&#xa0;mg of subcutaneous glucagon before scanning. From February 15, 2024 to February 11, 2025 33 such patients were recruited to undergo an additional, research exam without glucagon. All exams were acquired at 3T. An axial T2-weighted spin-echo series (T2-WI) was acquired within both exams. Evaluation of the T2-WI series was done by three experienced radiologists using the criteria of diagnostic quality (0–3 scale), PI-QUALv2 (0–3 sum), motion artifact (significant, visible, none), and reviewer preference (five-point relative scale). Due to differences in prescribed coverage, the scan times for the two T2-WI sequences were in general different for each subject. Results were stratified using the acquisition time ratio (T_rel) between the glucagon vs. non-glucagon scans. Wilcoxon tests assessed score differences.</p> Results <p>Across all 33 subjects, no significant differences were found between glucagon and non-glucagon scans. However, the observed negative correlation between glucagon preference and T_rel (<i>p</i> = 0.026) led to stratification into low-T_rel (<i>N</i> = 16) and high-T_rel (<i>N</i> = 17) groups. In the low-T_rel group the glucagon scans provided significantly improved diagnostic quality (<i>p</i> = 0.048), PI-QUALv2 sum (<i>p</i> = 0.049), motion scores (<i>p</i> = 0.047), and reader preference (<i>p</i> = 0.042).</p> Conclusion <p>Subcutaneous glucagon provides improved image quality in prostate T2-WI MRI when scan duration remains within 1.25× of that of a non-glucagon T2-WI series. The benefit appears to decrease with longer scan times.</p> Graphical abstract <p></p>