Lilly and Novo Bet on New Hormone to Build Next Big Weight-Loss Drugs

You've probably heard of popular weight-loss drugs like Ozempic, Zepbound, and Mounjaro. Now, two giant drug companies — Eli Lilly and Novo Nordisk — are working on a new kind of treatment that could make weight loss even more powerful.

These current drugs work through something called GLP-1 (a hormone that helps control hunger and makes you feel full). The new drugs target a different hormone called amylin (also released by the pancreas, it helps control appetite and fullness). The idea is to either use amylin drugs on their own or add them on top of existing GLP-1 drugs for even better results.

Lilly just shared encouraging early results. Its experimental amylin drug, eloralintide, was tested with tirzepatide (the main ingredient in Zepbound and Mounjaro):

• People on the highest-dose combination lost 23.3% of their body weight in 48 weeks
• Those on tirzepatide alone lost 14.8%
• This was tested in patients with obesity and Type 2 diabetes

Why this matters: Analysts estimate Lilly's eloralintide products could earn $23.2 billion in yearly sales by 2035. Over 10 million people have tried GLP-1 drugs and failed — because the drugs didn't work well for them, caused side effects, or their genes meant they didn't respond. Amylin drugs could offer these people a new option.

But there's a catch. Side effects were a problem in the combination treatment:

• Between 10.8% and 27% of patients on both drugs quit due to side effects
• Only 2.9% quit when taking tirzepatide alone

Experts warned that "27% is not a good number" — a treatment only helps if people can actually stay on it.

Novo Nordisk is racing in the same direction. Its amylin drug, cagrilintide, combined with semaglutide (called CagriSema), is expected to launch early next year.

The bottom line: Both companies believe amylin is the key ingredient for the next wave of weight-loss drugs. The early results are promising, but larger trials still need to prove these treatments are both effective and safe enough for people to keep taking.

This is an AI-generated summary. Read the original article at: https://www.cnbc.com/2026/10/02/lilly-novo-amylin-obesity-drugs.html