Oseltamivir acid (also known as oseltamivir carboxylate) is the active metabolite of the antiviral prodrug oseltamivir phosphate (Tamiflu®). It functions as a selective inhibitor of neuraminidase, a surface enzyme essential for influenza A and B viruses to release from infected host cells and spread infection. This mechanism reduces viral replication, making it valuable in antiviral research, pharmaceutical development, and as a reference standard for analytical and quality control purposes.

Commonly utilized in laboratory settings for studies on influenza pathogenesis, drug resistance, and structure-activity relationships. It is supplied as a high-purity (≥99%) white to off-white powder, confirmed by IR spectroscopy and purity assays, suitable for research applications only. Not for human therapeutic use.