Lilly calls Zepbound the most prescribed weight management medication of 2025

Eli Lilly announced on Feb. 23, 2026 that the FDA approved a label expansion for Zepbound (tirzepatide) to include a four-dose, single-patient KwikPen that holds a full month of treatment in one device ^[1]. In the same release, the company called Zepbound "the most prescribed weight management medication in 2025" ^[1][2].

The new pen is available by prescription through LillyDirect, the company's direct-to-patient platform. Lilly says patients paying out of pocket can get any Zepbound dose in either the multi-dose KwikPen or a single-dose vial at the same self-pay price, starting at $299 per month for the 2.5 mg dose ^[1]. Zepbound is sold in 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg strengths; the 2.5 mg is a starting dose and not an approved maintenance dose ^[1].

What Lilly claimed about market share

Two separate claims appear in the announcement, and they are not identical in scope. The headline says Zepbound was the most prescribed weight management medication in 2025 ^[1][2]. A quote from Ilya Yuffa, executive vice president and president of Lilly USA and Global Customer Capabilities, uses a narrower phrase: "Zepbound is the #1 prescribed injectable obesity-management medication" ^[1]. Both statements carry footnote markers in the release, but the text of those footnotes is not included in the material available here, so the underlying data source and exact measurement method are not verifiable from the release itself.

Lilly also said that in 2025, one out of every three new patients starting a branded weight management medication was prescribed Zepbound self-pay vials ^[1][2]. Separately, the company said more than 1 million patients accessed Lilly treatments through LillyDirect in 2025, and described its self-pay pricing as a 50% or greater discount compared with the list price of other incretin (GLP-1) medicines for obesity ^[1]. That comparison is to list price, not to what insured patients or people using other manufacturers' savings programs actually pay.

The efficacy numbers cited

The release repeated trial results. In SURMOUNT-1, a 72-week study of adults without diabetes, average weight loss was 15.0% (34 lbs) at 5 mg, 19.5% (44 lbs) at 10 mg, 20.9% (48 lbs) at 15 mg, and 3.1% (7 lbs) with placebo ^[1]. Average starting weights ranged from 226.8 to 233.3 lbs across groups ^[1].

In SURMOUNT-5, a 72-week open-label head-to-head trial against injectable Wegovy (semaglutide), participants on their maximum tolerated Zepbound dose (10 mg or 15 mg) lost an average of 20.2%, or 50 lbs, compared with 13.7%, or 33 lbs, for those on maximum tolerated Wegovy (1.7 mg or 2.4 mg) ^[1]. Lilly's own description notes the study design was open-label, adding that data "collected in a less rigorous study so findings are less certain" and that factors beyond the studied medicines may have contributed ^[1].

Why it matters for patients

Device format affects day-to-day handling. A four-dose pen means one device per month instead of four separate single-dose vials, and Lilly is pricing both the same for self-pay customers starting at $299 for the starting dose ^[1]. Prices for higher maintenance doses are not spelled out in the release beyond the "starting at" figure, so what a person pays at 10 mg or 15 mg is not stated here.

Market-share claims are marketing statements, not clinical findings. "Most prescribed" says nothing about whether a drug is right for any individual, and the release does not compare safety across products. The label carries a boxed warning about thyroid C-cell tumors, including medullary thyroid carcinoma, and lists risks such as pancreatitis, gallbladder problems, dehydration and kidney problems, and severe stomach problems ^[1]. Common side effects include nausea, diarrhea, vomiting, constipation, abdominal pain, injection site reactions, fatigue, belching, hair loss and heartburn ^[1]. Lilly also warns that a KwikPen should not be shared with anyone else, even with a new pen needle, because of infection risk ^[1].

What happens next

The KwikPen is available now by prescription through LillyDirect ^[1]. Whether commercial insurers and pharmacy benefit managers will cover the pen format on the same terms as vials is not addressed in the announcement.