FDA again classes retatrutide as a drug, not a biologic, as Lilly's court appeal stalls on a procedural question
On 2 October the FDA told Lilly that retatrutide, with a 39-amino-acid chain, does not count as a protein, so any US application must go through the standard new-drug route. The appeals court has asked both sides whether Lilly can appeal at this stage and has not ruled; Lilly says it will file for approval by the first quarter of 2027. Retatrutide is still unapproved anywhere.
Image credit: Prof. Peptide
Source: Prof. Peptide (17 Oct 2026).