Loperamide, primarily known as an antidiarrheal agent, has been investigated for potential use in Cluster Headache due to its ability to modulate opioid receptors in the central nervous system. While not a first-line treatment, some studies suggest it may have a mild analgesic and potentially preventive effect by interacting with mu-opioid receptors in pain pathways, though its efficacy for Cluster Headache remains limited and requires further research.