Research use only (RUO)
"Research use only" is a label some sellers put on chemicals to say they are not meant for people. The label does not make a product legal to use as a medicine. The FDA looks at what a product is really intended for, not just the words on the label.
For experts
Under 21 CFR 201.128, intended use is determined from the objective intent of the persons responsible for labelling, shown by labelling claims, advertising, statements, or the circumstances of distribution. In 2026 FDA warning letters, the agency stated that products labelled "research use only" and "not for human consumption" were nonetheless intended to be drugs for human use, and treated them as unapproved new drugs. In those cases the RUO disclaimer did not stop FDA from treating the products as drugs.
Sources (3)
- 0121 CFR 201.128 - Meaning of "intended uses"Electronic Code of Federal Regulations (eCFR), Office of the Federal Register · 2026-09-25 · accessed 2026-09-29
- 02FDA Warning Letter 734884: 'research use only' labeling and intended use of unapproved drug productsU.S. Food and Drug Administration, CDER Office of Unapproved Drugs and Labeling Compliance · 2026-08-24 · accessed 2026-09-29
- 03FDA Warning Letter 721806: 'research use only' labeling and intended use of unapproved drug productsU.S. Food and Drug Administration, CDER Office of Unapproved Drugs and Labeling Compliance · 2026-03-31 · accessed 2026-09-29