Cinobufagin is a bufadienolide steroid (C₂₄H₃₂O₅) isolated from the venom of the Chinese toad Bufo bufo gargarizans. It is primarily used in traditional Chinese medicine for its potent anti-cancer properties. It has shown significant activity against various tumor cells, including liver, lung, and colon cancers, by inducing apoptosis and inhibiting cell proliferation. The compound also exhibits anti-inflammatory and analgesic effects, making it useful in formulations aimed at symptom relief in cancer patients. Due to its strong biological activity and potential cardiotoxicity, it is often included in small amounts in topical and oral preparations for managing pain and swelling, under strict medical supervision. Research continues to explore its potential in modern oncology, particularly in developing targeted therapies with enhanced efficacy and reduced side effects.