• Clinical trials
• FDA
• Compounding

Retatrutide vs. Ozempic: what the TRANSCEND-T2D-2 head-to-head found, and why it still can't be compounded

By Peptide Policy Watch editorial team · Published October 29, 2026

Lilly's investor call on Thursday morning was mostly about money: $24.4 billion in quarterly revenue, a raised full-year forecast, a stock that jumped. Tucked into the pipeline section was a line people in the obesity world had been waiting on for months. Retatrutide, the triple-hormone drug that keeps setting weight-loss records, had just gone up against Ozempic in people with type 2 diabetes. It won on both blood sugar and weight.

So does that make it the next big diabetes drug, and can anyone get it now? The first answer is "maybe, once FDA rules." The second is a flat no, for reasons that come straight from federal law.

Facts are as of October 29, 2026. Sources, with retrieval dates, are at the bottom.

• 2.2 vs 1.8average A1C drop, both retatrutide groups vs Ozempic, 80 weeks (RCT, open-label) [V]
• 20.9% vs 9.4%average weight loss, higher retatrutide group vs Ozempic (RCT, efficacy estimand) [V]
• 1,298adults with type 2 diabetes randomized [V]

What Lilly announced, and when

The trial readout came first, in an October 28, 2026 Lilly release. [V] A day later, Lilly's third-quarter results filing with the SEC listed "positive topline results from a head-to-head Phase 3 trial of retatrutide" among its pipeline highlights. [V] That filing also reported quarterly revenue up 39% to $24.4 billion, driven mostly by Mounjaro and Zepbound. [V] CNBC reported that Lilly raised its 2026 revenue outlook to $91 billion to $92 billion and that shares rose about 9% on the day. [S]

What the quarterly filing didn't do is move the approval timeline. We found no new retatrutide filing date in it. [V] The most recent stated plan is still the one from Lilly's July 23, 2026 release: a Biologics License Application to FDA in the first quarter of 2027. [V] We haven't seen a transcript of the call itself, so anything said aloud about timing is unconfirmed here. [U]

The trial in one paragraph

TRANSCEND-T2D-2 (NCT06260722) is a randomized, open-label phase 3 study. Its 1,298 participants had type 2 diabetes that wasn't controlled well enough on metformin, with or without an SGLT2 inhibitor, and an A1C between 7.0% and 10.5% at entry. [V] They were split 2:2:1 between two retatrutide groups and Ozempic, all once weekly, and followed for 80 weeks. [V] The primary goal was to show that the higher retatrutide group was no worse than Ozempic at lowering A1C after 80 weeks; secondary endpoints tested whether retatrutide did better on A1C, weight and other measures. [V] About 650 participants then continue on retatrutide for another 24 weeks in an extension. [V] On ClinicalTrials.gov, the study shows an actual primary completion date of August 27, 2026, and it's listed as active, not recruiting, with an extension still running. [V]

The results, as Lilly reported them

Start with blood sugar, since this is a diabetes trial. Participants began at an average A1C of 8.3%. Both retatrutide groups brought it down by an average of 2.2 points, compared with 1.8 points on Ozempic. [V] Lilly says retatrutide met the primary endpoint and every key secondary endpoint. [V]

Weight is where the gap widened. From an average starting weight of 102.4 kg (about 226 lb), people in the two retatrutide groups lost 19.5% and 20.9% of body weight on average, about 44 and 47 pounds. The Ozempic group lost 9.4%, about 21 pounds. [V] That's more than double the Ozempic result, in people who on average started with a BMI of 36.8. [V] People with diabetes usually lose less weight on these drugs than people without it, BioPharma Dive noted in July. [S]

Lilly also reported bigger improvements than Ozempic in blood pressure (systolic), triglycerides and non-HDL cholesterol. [V] Those are risk-factor readings, not heart attacks or strokes; a separate outcomes trial is designed to answer that question. [V]

Why a head-to-head matters

Most drug trials compare a new medicine with a placebo. That tells you whether it works, not how it stacks up against what doctors already prescribe. TRANSCEND-T2D-2 is the first phase 3 trial to put retatrutide against another incretin drug, Lilly says. [V] Ozempic is the semaglutide brand for type 2 diabetes, and the comparison used it at its highest approved strength. [V]

It also fills a gap in the story so far. The TRIUMPH obesity trials showed headline weight loss; our retatrutide explainer walks through all of them. [V] The TRANSCEND-T2D program is the diabetes side: three registrational trials with more than 2,050 participants, started in 2024. [V] A diabetes approval would usually lean on trials like this one.

Then there's the matchup everyone is waiting for. TRIUMPH-5 compares retatrutide directly with tirzepatide, Lilly's own Mounjaro and Zepbound, in adults with obesity. [V] Lilly lists it as ongoing, and ClinicalTrials.gov gives an estimated primary completion of November 2026. [V] That's a registry estimate, not a promised announcement date. [V]

Six phase 3 wins, one molecule

Retatrutide acts on three hormone receptors at once: GIP, GLP-1 and glucagon. [V] Lilly is studying it in obesity, type 2 diabetes, knee osteoarthritis pain, obstructive sleep apnea, chronic low back pain, heart outcomes and the fatty liver disease MASLD. [V] With TRANSCEND-T2D-2, Lilly counts six phase 3 trials that have delivered strong efficacy results. [V] Results from two sleep apnea trials within the TRIUMPH program appeared in the New England Journal of Medicine on October 21, 2026. [V]

If the BLA goes in on schedule, FDA would then decide whether to accept it and set a review clock. No decision date exists, because no application has been filed that we can find. [U] For how phases and registry dates work, see how to read a clinical-trial listing.

Can retatrutide be compounded now? Still no

Big trial news tends to bring a wave of "where can I get it" posts. Federal law hasn't moved.

A 503ASection of federal drug law covering compounding by state-licensed pharmacies and doctors, usually for a prescription written for one patient. Glossary entry pharmacy can compound from a bulk ingredient only if it has a USP or NF monograph, appears in a drug FDA has already approved, or is on FDA's 503A bulks list. [V] FDA told the National Association of Boards of Pharmacy in a March 31, 2025 letter that retatrutide fits none of those, and isn't on the 503BSection of federal drug law for outsourcing facilities: larger compounders that register with FDA and must follow drug-manufacturing quality rules. Glossary entry list or tied to a shortage either. [V] FDA's GLP-1 page, checked October 29, 2026, says it "cannot be used in compounding under federal law." [V]

The HHS enforcement discretion policy that went on public inspection October 28 names six peptides: BPC-157, TB-500, epitalon, KPV, MOTS-c and semax. Retatrutide isn't one of them. [V] The notice is scheduled to publish in the Federal Register on October 30. [V] Our line-by-line look at the HHS policy and retatrutide covers the details, and the HHS interim policy breakdown lays out all ten conditions.

Lilly's new release is blunter than usual on this point. Its FAQ says no one is legally allowed to sell retatrutide to patients, because it isn't approved by any regulator anywhere. [V]

Regulators have been acting on that for a while. FDA has issued warning letters calling retatrutide products unapproved new drugs, including letters 721806 and 721600 (March 31, 2026) and 735063 (August 24, 2026). [V] Lilly filed six lawsuits on August 12, 2026 against US entities selling unapproved retatrutide and says it referred more than 200 people and companies to authorities. [V] On September 17, 2026, twenty state attorneys general wrote to the Secretary of State about foreign-made ingredients in compounded GLP-1 drugs, retatrutide among them. [V] Lilly's quarterly filing even lists "illegally compounded products" among its business risks. [V] For the telehealth side, see what FDA and Lilly say about telehealth retatrutide offers.

Limits and unknowns

• These are topline results in a company release. Full data will come at a medical meeting and in a journal, per Lilly, and haven't been peer reviewed yet. [V]
• The trial was open-label, so participants and investigators knew who got what. [V] Lilly funded it. [V]
• All figures are for the efficacy estimand, which estimates the effect if everyone had stayed on treatment. Results counting everyone, regardless of whether they stopped, weren't in the release. [V]
• Lilly notes that superiority comparisons for the lower retatrutide group on A1C and systolic blood pressure reached only nominal significance, outside the trial's main error control. [V]
• Side effects were mostly gastrointestinal. Diarrhea was reported in 28.3% and 32.7% of the retatrutide groups against 26.4% on Ozempic, and dysesthesia, an unusual skin sensation, in 4.8% and 6.5% against 2.7%. Lilly says most events were mild to moderate. [V]
• More people quit for adverse events on retatrutide: 4.8% and 7.9% of the two groups against 2.7% on Ozempic. [V]
• The comparator was semaglutide, not tirzepatide. How retatrutide compares with Lilly's own drug awaits TRIUMPH-5. [V]

What to watch next

Sources (retrieved October 29, 2026 unless noted)

1. Eli Lilly, "Lilly's retatrutide delivered greater A1C reduction and more than double the weight loss of Ozempic's highest approved dose in head-to-head trial," October 28, 2026 [V] — https://investor.lilly.com/news-releases/news-release-details/lillys-retatrutide-delivered-greater-a1c-reduction-and-more
2. Eli Lilly, Form 8-K, Exhibit 99, third-quarter 2026 results, filed October 29, 2026 (SEC EDGAR) [V] — https://www.sec.gov/Archives/edgar/data/59478/000005947826000104/q326lillysalesandearningsp.htm
3. ClinicalTrials.gov, NCT06260722 (TRANSCEND-T2D-2), record last updated September 28, 2026 [V] — https://clinicaltrials.gov/study/NCT06260722
4. ClinicalTrials.gov, NCT06662383 (TRIUMPH-5) [V] — https://clinicaltrials.gov/study/NCT06662383
5. Eli Lilly, TRIUMPH-2 and TRIUMPH-3 release, July 23, 2026 (retrieved October 26, 2026) [V] — https://investor.lilly.com/news-releases/news-release-details/lillys-triple-agonist-retatrutide-successful-two-additional
6. FDA, "FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss" [V] — https://www.fda.gov/drugs/drug-alerts-and-statements/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
7. FDA letter to NABP on retatrutide, March 31, 2025 (via Ohio Board of Pharmacy) [V] — https://www.pharmacy.ohio.gov/documents/pubs/special/compounding/fda%20letter%20-%20retatrutide%20in%20compounded%20drug%20products.pdf
8. Federal Register public inspection, "Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances," FR Doc. 2026-22192, filed October 28, 2026 [V] — https://www.federalregister.gov/public-inspection/2026-22192/enforcement-discretion-policy-regarding-503a-compounding-using-certain-peptide-bulk-drug-substances
9. Eli Lilly, "Lilly calls on online platforms, payment companies and regulators to shut down the illegal retatrutide black market," August 12, 2026 (retrieved October 25, 2026) [V] — https://investor.lilly.com/news-releases/news-release-details/lilly-calls-online-platforms-payment-companies-and-regulators
10. Letter from 20 state attorneys general to the Secretary of State, September 17, 2026 (Missouri AG copy; retrieved October 25, 2026) [V] — https://ago.mo.gov/wp-content/uploads/2026.09.17-Letter-to-Sec.-Rubio-re-GLPs.pdf
11. PubMed, retatrutide obstructive sleep apnea trials, NEJM, October 21, 2026 (retrieved October 26, 2026) [V] — https://pubmed.ncbi.nlm.nih.gov/42904878/
12. BioPharma Dive, "Lilly, with new data, to seek FDA approval of obesity drug retatrutide," July 23, 2026 (retrieved October 29, 2026) [S] — https://www.biopharmadive.com/news/lilly-retatrutide-fda-application-obesity-drug-results/825987/
13. CNBC, "Eli Lilly hikes sales outlook, as CEO says there's room for 'dramatic' obesity market expansion," October 29, 2026 [S] — https://www.cnbc.com/2026/10/29/eli-lilly-lly-earnings-q3-2026.html

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