Ractopamine () is an animal feed additive used to promote leanness and increase food conversion efficiency in farmed animals in few countries, banned in most. Pharmacologically, it is a phenol-based TAAR1 agonist and β adrenoreceptor agonist that stimulates β1 and β2 adrenergic receptors. It is most commonly administered to animals for meat production as ractopamine hydrochloride. It is the active ingredient in products marketed in the US as Paylean for swine, Optaflexx for cattle, and Topmax for turkeys. It was developed by Elanco Animal Health, a former division of Eli Lilly and Company.
{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 458436321 | ImageFile = Ractopamine.svg | ImageClass = skin-invert-image | ImageSize = 260px | PIN = 4-(1-Hydroxy-2-{[4-(4-hydroxyphenyl)butan-2-yl]amino}ethyl)phenol | OtherNames =
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Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).