Research-use-only.

Labeled for laboratory research, not human use.

Research-use-only, usually abbreviated RUO, is a labelling category indicating that a material is sold for laboratory research and is not approved, evaluated, or intended for human consumption, clinical use, or diagnostic use. It is worth being blunt about what this designation is: a regulatory posture, not a quality grade. Research-use-only says nothing about purity, sterility, endotoxin content, manufacturing standards, or the accuracy of the label, and it is not a tier below pharmaceutical grade on a shared scale. It describes what the seller is permitted to claim and what regulatory framework the product sits outside of. Material produced under this label has generally not been made in a facility operating to pharmaceutical manufacturing standards, has not been released against injectable specifications, and carries no requirement that the vial contains what the label says in the amount stated. Phrases such as research grade and lab grade that appear in marketing have no standardised meaning and no certifying body behind them. The practical consequence is that the label functions as a legal boundary between the seller and the buyer rather than as information about the product, and it explicitly places responsibility for any human use entirely on the person who chooses it.