Abstract: Guggulsterone (GS) is a bioactive compound primarily extracted from the oleo-gum resin of plants in the Commiphora and Boswellia genera. Modern pharmacological studies have demonstrated that GS possesses a broad spectrum of biological activities, with notable therapeutic potential in inflammatory disorders, neurodegenerative conditions, diabetes mellitus, and various cancers. In this review, we systematically analyzed relevant literature published up to 2024 from the CNKI, Web of Science, ScienceDirect, and PubMed databases to summarize the current understanding of GS’s pharmacological effects, toxicity profile, and pharmacokinetic properties. The findings indicate that GS exerts potent antioxidant, anti-inflammatory, anticancer, antiviral, antidepressant, lipid-lowering, and cardiovascular protective effects, primarily through modulation of key signaling pathways such as the Janus kinase (JAK)-signal transducer and activator of transcription 3 (STAT3), nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1), Nrf2/Keap1, nuclear factor kappa-B (NF-κB), AMPK, phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), and mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1). Additionally, GS may help overcome limitations associated with conventional chemotherapy by modulating drug resistance via regulation of p-glycoprotein activity. Following hepatic metabolism mediated by cytochrome P450 enzymes, GS does not appear to cause significant adverse effects. This review provides a comprehensive synthesis of the sources, pharmacological actions, safety, pharmacokinetics, and potential applications of GS. Future research should focus on structural modification of GS, development of novel formulations, and exploration of synergistic combinations with other therapeutic agents to broaden its clinical utility.