Eli Lilly's Pipeline: What Comes After Zepbound

Zepbound is not the end of the road for Eli Lilly. It is the middle of it.

The company has three obesity candidates in or near late-stage testing, a pill it launched in April 2026 that it is pushing into new uses, and a shopping list that ran to more than $25 billion in the first half of 2026 alone. Some of this is genuinely exciting. Some of it is years away. And one of these drugs has already produced a black market big enough that Lilly is suing people over it.

Here is the honest state of play, and what it does and does not mean for you.

What is retatrutide, and how good is it?

Retatrutide is the one everybody is waiting for.

Zepbound works on two hormone receptors, GIP and GLP-1. Retatrutide works on three: GIP, GLP-1 and glucagon. The third one is the difference. Glucagon signaling is thought to raise the amount of energy the body burns, on top of the appetite effects the other two produce. It is a once-weekly injection.

The numbers from TRIUMPH-1, reported in May 2026, are the largest ever seen in a Phase 3 obesity trial. Among 2,339 adults with obesity or overweight plus at least one weight-related condition [1]:

• 4 mg: average 19.0% weight loss (about 47.2 pounds) at 80 weeks
• 9 mg: average 25.9% (about 64.4 pounds)
• 12 mg: average 28.3% (about 70.3 pounds)
• Placebo: average 2.2% (about 5.5 pounds)

At the highest dose, 45.3% of participants lost at least 30% of their body weight, a threshold historically associated with bariatric surgery. In an extension out to 104 weeks, people who stayed on the 12 mg dose averaged about 30.3%, roughly 85 pounds.

Those figures are on what researchers call the efficacy estimand, meaning they describe people who stayed on treatment. That matters, because staying on it was harder at higher doses. Discontinuation because of side effects ran 4.1% at 4 mg, 6.9% at 9 mg and 11.3% at 12 mg, against 4.9% on placebo [1]. The common side effects were nausea, diarrhea and constipation.

In July 2026, Lilly reported that two more Phase 3 trials, TRIUMPH-2 and TRIUMPH-3, had also succeeded, and said the clinical data package was complete. It plans to submit a Biologics License Application to the FDA in the first quarter of 2027 [2][3].

So: no approval, no launch date, and no legal way to get it.

Why is there a retatrutide black market, and why does it matter?

Because the recipe is public.

Ingredient information for investigational drugs appears in patent filings, and peptide manufacturers can work from that. The result is that retatrutide has been sold online for years under labels like “research grade,” “not for human consumption” and simply “reta,” to people who read the trial headlines and did not want to wait.

Lilly moved against it in August 2026. On August 12 the company filed its first six lawsuits, naming a pharmacy near Houston, an aesthetics business in Sacramento and four online peptide sellers in Texas and North Carolina [4][5]. It says it has reported more than 14,000 websites, advertisements, social media posts and product listings marketing retatrutide across more than 100 countries, and has referred more than 200 people and entities to the FDA, the Department of Justice, state attorneys general and law enforcement [4].

Lilly’s chief medical officer, David Hyman, put it this way: “What is being sold on the black market is not a medicine — it is entirely unverified, unapproved and not worth the risk” [5].

You can discount some of that as a company protecting a future product. Two things are independently on the record. The FDA has said that these products are illegal to sell for human use, that retatrutide cannot be lawfully compounded, and that so-called “research-use only” products are of unknown quality and may be harmful [4]. Lilly, for its part, says patients have reported serious harms including hospitalizations after taking black-market retatrutide bought online; that second claim comes from the company and has not been independently confirmed [5]. No regulator anywhere has reviewed any of these products for what is in them, how much is in them, or whether they are sterile.

The company has also called on social media platforms, e-commerce sites, payment processors and shipping companies to cut off the trade, arguing that reporting listings has not been enough because platforms are not removing them fast enough [4][5].

If you are tempted, the practical point is simple: there is no way to know what is in the vial.

What is eloralintide, and why is Lilly excited about it?

Eloralintide is Lilly’s bet on a different hormone entirely.

Amylin is released alongside insulin and helps signal fullness. It is not GLP-1, and drugs that target it may produce weight loss through a partly different route, with a different side-effect profile. The commercial hope is straightforward: comparable results with less nausea.

In a 48-week Phase 2 study of 263 adults with obesity or overweight and at least one weight-related condition, but without type 2 diabetes, average weight loss was [6]:

• 1 mg: 9.5%
• 3 mg: 12.4%
• 6 mg: 17.6%
• 9 mg: 20.1%
• Placebo: 0.4%

The most frequently reported side effects were mild to moderate gastrointestinal symptoms and fatigue, more common at higher doses. Notably, the 1 mg and 3 mg groups, which escalated more slowly, reported rates comparable to placebo [6].

Those Phase 3 trials are now running. ENLIGHTEN-1, which tests eloralintide on its own in 1,980 adults with obesity or overweight, started on February 6, 2026, and ENLIGHTEN-6, which tests it added on top of a weekly incretin, started on February 10, 2026. Both were still recruiting in September 2026, and primary results are not expected before 2028 [17]. Lilly is also evaluating eloralintide in combination with tirzepatide.

Phase 2 results are not Phase 3 results. Tolerability claims in particular have a habit of looking better in smaller studies. But if the profile holds, an amylin drug gives Lilly a second mechanism to sell, and an option for people who cannot tolerate GLP-1 side effects.

What about muscle loss? Is Lilly doing anything about that?

Yes, though the picture is messier than the marketing.

Bimagrumab is an antibody that blocks the activin type II receptor, a pathway involved in muscle growth. Lilly acquired it in 2023 by buying Versanis Bio for up to $1.925 billion. The idea is to pair it with an incretin drug so that more of the weight lost is fat and less of it is lean tissue.

A Phase 2 trial of bimagrumab plus semaglutide reported about 22% body weight reduction at 72 weeks with roughly 92% of the loss coming from fat mass, published in Nature Medicine.

But in September 2025, Lilly stopped one Phase 2 study combining bimagrumab with tirzepatide in people with type 2 diabetes, citing what it called strategic business reasons rather than a safety or efficacy problem [7]. Other studies continued.

Read that as what it is: an active but unsettled program. Muscle preservation is one of the most common worries readers have about this class of drug, and the honest answer in September 2026 is that no drug has been approved to address it and the leading candidate has had at least one trial pulled.

What is happening with Foundayo, the pill?

Foundayo (orforglipron) was approved on April 1, 2026 and began shipping through LillyDirect on April 6, with broad US availability from April 9 [8]. The FDA cleared it 50 days after Lilly filed, under the Commissioner’s National Priority Voucher pilot, and 294 days ahead of its original January 20, 2027 decision date [16]. It is the first small-molecule, non-peptide GLP-1 approved for weight management, which is why it can be taken at any time of day without the food and water restrictions that oral semaglutide requires.

Its launch has been slower than Lilly expected. It recorded $98 million in its first quarter against roughly $130 million of analyst expectations, while Novo Nordisk’s Wegovy pill took about $496 million in the same period. By Lilly’s own account the US prescriber base grew from about 8,000 to about 36,000 between the first and second quarter earnings calls, and coverage from all three major pharmacy benefit managers only arrived in June 2026 [9].

The forward story for Foundayo has three parts: expanding into type 2 diabetes, where Lilly has filed in the US, EU and Japan; expanding internationally, with reviews underway in more than 40 additional countries; and building brand awareness for a name nobody had heard a year ago.

What is Lilly buying, and why?

A lot, and for a reason that shows up clearly in the accounts.

Two brands containing one molecule produced about 56% of Lilly’s 2025 revenue and roughly two thirds of its second-quarter 2026 revenue. Lilly’s own annual report says anti-obesity medicines make up “a significant portion” of revenue [10]. The US compound patent on tirzepatide runs to 2036 [10]. That is a long time in ordinary terms and a short time in drug development terms, because a replacement discovered today would barely make it to market by then.

So Lilly has been converting tirzepatide cash into early-stage science. The 2026 list alone includes:

• Orna Therapeutics (February, up to $2.4 billion) — circular RNA and lipid nanoparticles for programming immune cells inside the body
• Centessa Pharmaceuticals (March, about $6.3 billion upfront) — orexin-2 receptor agonists for narcolepsy and other sleep-wake disorders
• Kelonia Therapeutics (April, up to $7 billion) — engineered lentiviral delivery for in vivo CAR-T cell therapy
• Ajax Therapeutics (April, up to $2.3 billion) — a type II JAK2 inhibitor for myelofibrosis
• Curevo, LimmaTech and Vaccine Company (May, up to about $3.8 billion combined) — an entire infectious disease vaccine business created in a single announcement
• AtaiBeckley (July, about $2.8 billion upfront) — rapid-acting treatments for treatment-resistant depression
• Merida Biosciences (August, up to $2.875 billion) — a platform that selectively destroys disease-causing antibodies

That is on top of Ventyx Biosciences in January and follows SiteOne, Verve and Adverum in 2025 [11][12].

Almost none of these companies has an approved product. Analysts have noted the contrast with Pfizer, which spent its COVID windfall on large commercial-stage acquisitions including Seagen; Lilly has spent its windfall on Phase 1 and Phase 2 platforms. Whether that is prudence or optimism will not be clear for a decade.

Two more items belong in the same category. In August 2025 Lilly signed a collaboration with Superluminal Medicines worth up to $1.3 billion to hunt for obesity drugs that work on G protein-coupled receptors, starting with a melanocortin 4 receptor agonist — a mechanism outside the incretin family entirely [13]. And in October 2025 it announced a drug discovery supercomputer built with NVIDIA, using more than 1,000 B300 GPUs, described as the first of its kind in the industry [14].

What does Lilly make that has nothing to do with weight?

More than people assume. In cancer: Verzenio for breast cancer, Jaypirca for certain leukemias, Retevmo for RET-driven cancers and Inluriyo, approved in September 2025. In immune disease: Taltz, Omvoh and Ebglyss. In neuroscience: Kisunla for early symptomatic Alzheimer’s disease. Plus Jardiance, Trulicity and the insulins.

In the second quarter of 2026, Ebglyss brought in $201 million and Jaypirca $192 million [9]. Real businesses. Just not, yet, anything close to $9.94 billion a quarter.

How should a patient read all of this?

Carefully, and with dates attached.

Nothing described here as a pipeline asset is available to you. Retatrutide is not approved. Eloralintide is not approved. Bimagrumab is not approved. Trial results, however impressive, describe what happened to people enrolled in a study under supervision, not what will happen to any individual.

The one practical takeaway is the warning about the retatrutide gray market, because that is the one place where reading about a pipeline drug leads directly to a decision people are actually making. Everything else on this list is a question to raise with a healthcare provider, later, when and if it arrives.

Sources

1. Lilly’s triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial, May 21, 2026
2. Lilly’s triple agonist, retatrutide, successful in two additional Phase 3 obesity trials, July 23, 2026
3. Lilly reports second-quarter 2026 financial results, August 5, 2026
4. Lilly calls on online platforms, payment companies and regulators to shut down the illegal retatrutide black market, August 12, 2026
5. Lilly fighting black market for its next obesity drug — The Indiana Lawyer, September 8, 2026
6. Lilly’s selective amylin agonist, eloralintide, demonstrated meaningful weight loss in a Phase 2 study, November 6, 2025
7. Lilly to terminate obesity trial of bimagrumab with tirzepatide — BioPharma Dive
8. FDA approves Lilly’s Foundayo (orforglipron), April 1, 2026
9. Lilly’s obesity pill Foundayo ‘disappointed’ in Q2, as injectables continue to boom — Fierce Pharma
10. Eli Lilly and Company Form 10-K for the year ended December 31, 2025
11. Eli Lilly pipeline in 2026 fueled by the incretin franchise — Labiotech
12. Deal-hungry Lilly strikes up to $2.9B immuno play for Merida — BioSpace
13. Lilly Strikes $1.3 Billion GPCR Drug Discovery Pact with Superluminal
14. Lilly partners with NVIDIA to build the industry’s most powerful AI supercomputer, October 28, 2025
15. Lilly selects Pennsylvania as home for its newest injectable medicine and device manufacturing facility, January 30, 2026
16. FDA Approves First New Molecular Entity Under National Priority Voucher Program, April 1, 2026 — US Food and Drug Administration
17. ENLIGHTEN-1: a Phase 3 study of eloralintide in obesity or overweight without type 2 diabetes (NCT07321886) — ClinicalTrials.gov