Onseron Syrup 25 ml – Nausea & Vomiting ReliefOnseron Syrup 25 ml Effective Relief from Nausea and Vomiting Onseron Syrup 25 ml contains Ondansetron, a potent antiemetic used to prevent and treat nausea and vomiting caused by cytotoxic chemotherapy, radiotherapy, and surgical procedures. Ondansetron works by selectively blocking serotonin (5 HT3) receptors found in both the central and peripheral nervous systems. These receptors are responsible for initiating the vomiting reflex when serotonin is