IP stands for Intraperitoneal or administered through the peritoneum. The peritoneum is a thin, transparent membrane that lines the walls of the abdominal (peritoneal) cavity.DaveH wrote: ↑Tue Feb 25, 2020 1:29 pmSome of the references on this site to testing of products say that testing was done with IP or IV delivery of the thing being tested. I know that IV means intravenous and I understand what that is. But I don't know what IP means. Could you please inform me what it means?