The mechanism: The Inflation Reduction Act doesn't hit every blockbuster drug at once — it hits by launch date, moving down a clock that starts ticking the moment a small-molecule drug has been on the market nine years (or a biologic thirteen). Semaglutide, first approved as Ozempic in 2017, aged into eligibility on schedule: CMS already selected the full semaglutide family — Ozempic, Wegovy, and Rybelsus — for its second negotiation round, with negotiated Medicare prices (roughly $274/month, a 71% cut from list) taking effect January 2027. Tirzepatide, approved in 2022 as Mounjaro and 2023 as Zepbound, is younger by law. It isn't projected to reach a negotiation cycle until 2028 or 2029 at the earliest. Any legislative push to compress that IRA calendar — a bipartisan favorite pre-election — closes the gap for Lilly's newer franchise while doing nothing to un-negotiate Novo's price, which is already cemented. Novo eats the cut years before Lilly's flagship growth drug even enters the room.
Healthcare
Why Novo Nordisk, Not Lilly, Eats the Medicare GLP-1 Price Cut First
Semaglutide is already locked into Medicare's negotiated pricing for 2027 while tirzepatide isn't due until at least 2028-2029 — a two-year head start on margin compression the market keeps pricing as if both drugs sit in the same boat.
