The FDA announced plans to crack down on active pharmaceutical ingredients used by compounding pharmacies to produce off‑label GLP‑1 weight‑loss formulations, explicitly calling out major compounding suppliers and prompting immediate market reactions including Hims & Hers canceling a planned GLP‑1 pill launch and Novo Nordisk filing suit over alleged knockoffs. The agency’s notice aims to remove questionable active ingredients and curb unregulated mass production, citing safety and efficacy concerns. The move reshapes access for consumers seeking low‑cost alternatives and may squeeze legitimate compounders while legal disputes between originators and compounding firms play out.