Retatrutide Alternatives: How Other Weight Loss Drugs Compare

The strongest legal retatrutide alternatives right now are tirzepatide (Zepbound), semaglutide (Wegovy, in 3 forms) and Lilly's new daily pill, Foundayo (orforglipron), and none of them matches retatrutide's trial numbers. Counted the same way, retatrutide 12 mg averaged 25.0% weight loss over 80 weeks in TRIUMPH-1, against 20.9% over 72 weeks for tirzepatide 15 mg in SURMOUNT-1, the closest approved match. As of October 2026, retatrutide itself has no approved version anywhere, so every alternative below is a drug you can fill with a prescription today.

Every number below names its trial, and we say where two trials counted weight loss differently.

Where retatrutide stands on approval: Lilly last said, on September 29, 2026, that it plans to submit retatrutide to the FDA in the first quarter of 2027 as a Biologics License Application (BLA). On October 2, 2026, the FDA decided that retatrutide is a drug, not a biological product, so an application would need to be filed under section 505 of the Federal Food, Drug, and Cosmetic Act. Lilly's appeal on that question is pending in the Seventh Circuit, and we found no ruling as of October 31, 2026. The FDA approval and release date pages track what happens next.

Retatrutide alternatives compared side by side

The table puts each approved weight drug with a long published trial next to retatrutide, on one yardstick: average weight loss among everyone who started, including people who stopped their shots or pills. Drug labels call that the intention-to-treat result; Lilly's releases call it the treatment-regimen estimand. The last column applies each average to the same starting weight, 248.5 lb, the TRIUMPH-1 average. That's arithmetic on an average, not a forecast for any one person. The retatrutide weight loss results page has the full TRIUMPH-1 numbers.

Sources: TRIUMPH-1 from its NEJM paper (25.0%) and Lilly's release (28.3%); ATTAIN-1 from the Foundayo label; SURMOUNT-1 and STEP 1 from their NEJM papers; Wegovy HD and pill from the Wegovy label. Prices from LillyDirect and NovoCare, re-checked October 31, 2026 and unchanged since September. The Wegovy starter price and two Foundayo prices run only through December 31, 2026. With commercial insurance that covers them, Lilly and Novo Nordisk list copays as low as $25 a month, and Medicare Part D members who qualify can get the Zepbound KwikPen, Foundayo or any Wegovy dose for $50 a month with prior authorization from July 1, 2026 through December 31, 2027 (people with type 2 diabetes aren't eligible).

Retatrutide has no price. Lilly's October 2026 FAQ says only that it plans to price it "to reflect the overall value to the healthcare system," and the retatrutide price page covers what that leaves open.

These are separate trials with different people in them. TRIUMPH-1 started at an average BMI of 40.0, SURMOUNT-1 at 38 and the two Foundayo label trials at 36.5 on average, and a longer trial has more weeks to work. The only direct test against another weight drug is TRIUMPH-5, about 800 adults on retatrutide or tirzepatide for 80 weeks. ClinicalTrials.gov estimates its primary completion for November 2026 (as of October 2026), and Lilly's October 28 release still lists it as ongoing. Until it reads out, the retatrutide vs tirzepatide page is the place for the best like-for-like comparison.

Our read: if you want the most weight loss you can legally get today, tirzepatide 15 mg is the nearest thing to retatrutide, about 4 points behind on the same yardstick, with fewer people quitting over side effects (next table).

Why is retatrutide better on the scale?

Retatrutide acts on 3 hormone receptors. Tirzepatide acts on 2 of them (GIP and GLP-1), and semaglutide and orforglipron act on GLP-1 alone.

The extra one is the glucagon receptor. Lilly's 2022 discovery paper proposed that it raises the energy the body burns, on top of the appetite drop from GIP and GLP-1, but that part comes from lab work and hasn't been measured directly in people. What has been measured in people: in the Phase 2 liver substudy in Nature Medicine, a fat-burning marker in the blood (beta-hydroxybutyrate) rose 2 to 3 fold at 4 mg and above, and liver fat fell 86.0% on 12 mg by 48 weeks.

The bigger number comes with more people quitting over side effects, though not with more nausea than Wegovy 2.4 mg.

The skin symptom isn't unique to retatrutide: Wegovy's 7.2 mg dose had it more often than retatrutide 12 mg did (22% vs 12.5%, different trials). Lilly says most retatrutide cases were mild to moderate and resolved during treatment. The dropout column is the one to take to your doctor, because it's where retatrutide's top dose looks worst.

The 4 mg dose looks different. It averaged 17.6% counting everyone, between Zepbound 5 mg (15.0%) and 10 mg (19.5%), with fewer side-effect dropouts than placebo (4.1% vs 4.9%).

Full symptom data sits on the retatrutide side effects page.

Retatrutide vs tirzepatide, Zepbound and Mounjaro

Tirzepatide is one molecule sold under two Lilly brands. Zepbound is the weight and sleep apnea brand; Mounjaro is the type 2 diabetes brand. It's the only drug approved in the US that shares 2 of retatrutide's 3 targets.

• Retatrutide vs tirzepatide: the molecules compared, including why 28.3% vs 20.9% overstates the gap and what the diabetes trials show.
• Retatrutide vs Zepbound: weight results, the sleep apnea approval and what Zepbound costs to fill.
• Retatrutide vs Mounjaro: A1C results against TRANSCEND-T2D-1, where retatrutide lowered A1C by up to 2.0 points from a 7.9% start over 40 weeks (efficacy estimand).

Retatrutide vs semaglutide, Wegovy and Ozempic

Semaglutide is Novo Nordisk's GLP-1 drug. Wegovy is its weight brand, now in 3 forms (2.4 mg, 7.2 mg and a daily pill); Ozempic is the type 2 diabetes brand. In weight trials, retatrutide's average on 12 mg is about 10 points above Wegovy 2.4 mg's, counted the same way.

The first retatrutide head-to-head is against Ozempic. TRANSCEND-T2D-2 randomized 1,298 adults with type 2 diabetes on metformin, with or without an SGLT2 inhibitor, to retatrutide 9 mg, retatrutide 12 mg or Ozempic 2 mg for 80 weeks, without blinding. Lilly's October 28, 2026 topline: A1C fell 2.2 points on both retatrutide doses against 1.8 on Ozempic, and body weight fell 19.5% (9 mg) and 20.9% (12 mg) against 9.4%.

Those figures all assume everyone stayed on treatment (the efficacy estimand), and Lilly released none counting everyone who was randomized. The 12 mg comparisons with Ozempic were controlled for multiple testing, and only the 9 mg superiority claims for A1C and systolic blood pressure were nominal. The stomach side effects looked alike: on 12 mg, nausea was 23.8% against 21.3% on Ozempic, diarrhea 32.7% against 26.4%. Burning or oversensitive skin was 6.5% against 2.7%, and 7.9% of people on 12 mg stopped over side effects against 2.7% on Ozempic (4.8% on 9 mg). There's no journal paper yet. Lilly says detailed results will come at a medical meeting and in a journal, with no dates, and about 650 people are continuing retatrutide for 24 more weeks (the registry estimates study completion for February 2027).

Our read: in type 2 diabetes, retatrutide did more than double Ozempic's weight loss with a smaller A1C edge, and more people on 12 mg stopped over side effects. It tells you little about weight loss without diabetes, where the comparison to watch is TRIUMPH-5.

• Retatrutide vs semaglutide: the two molecules and their full trial records, including the 3 Wegovy forms, their weight results and self-pay prices.
• Retatrutide vs Ozempic: Ozempic's diabetes doses, the head-to-head in detail and what someone on Ozempic would want to know.

Is retatrutide a GLP-1, and is GLP3-R the same drug?

Retatrutide is partly a GLP-1 drug, because it switches on the GLP-1 receptor, but it also hits GIP and glucagon receptors. There's no hormone called GLP-3, and Lilly's own FAQ calls the name scientifically inaccurate. The is retatrutide a GLP-1 page walks through the receptor biology, and the GLP-3 explainer covers where the nickname came from.

GLP-3 and GLP3-R are names used online, not anything Lilly makes. An FDA warning letter in August 2026 went to a seller over a product called "GLP-3 Reta (Retatrutide)", and Victoria's health alert lists products labeled Reta, R-10 and R-20. When Australia's TGA tested a vial sold as retatrutide after a user was hospitalized, it held no retatrutide, only undeclared semaglutide at about 8 times the level in approved products. The same alert, issued in June 2026, linked 6 cases of acute liver injury since January 2026 to products labeled retatrutide.

What's in the trials and what's in a vial sold as retatrutide can be different drugs. If you're weighing online vials anyway, our retatrutide for sale page covers how people check batch test reports and the red flags regulators have found, and is retatrutide legal covers where the law stands.

Daily pills and the next wave of drugs

Foundayo, approved April 1, 2026, is a once-daily pill you can take with or without food. It isn't a peptide, and its label lists a half-life of about 29 to 49 hours, against about 6 days for retatrutide. On weight it's the lightest of the approved options above, 11.1% at 72 weeks counting everyone. If needles are the dealbreaker, it's the pill without the Wegovy pill's routine of an empty stomach, up to 4 oz of water and a 30-minute wait.

Further out are survodutide and mazdutide. FDA's page on unapproved GLP-1 drugs, current as of October 1, 2026, names both among products being sold online without approval, and neither is approved in the US, so neither is a legal alternative here yet. The next-generation obesity drugs page tracks where each one stands.

Switching from tirzepatide or semaglutide

We couldn't find any published retatrutide data on people switching from another weight drug. Lilly's legal route for someone who has stalled is narrow: its expanded access program (NCT07629401) takes adults with a BMI of 35 or more despite the highest available dose of another weight drug, plus 2 or more serious weight-related conditions, and only through their doctor (how to get retatrutide covers the other routes). What changes when you switch, and what the labels say about gaps between doses, is on the switching from tirzepatide and switching from semaglutide pages.

Is reta like a steroid, and other quick answers

No, it isn't a steroid. Anabolic steroids are man-made versions of testosterone, per MedlinePlus. Retatrutide is a peptide that works on gut and pancreas hormone receptors to cut appetite, and nothing in its trials was designed to build muscle.

It's given under the skin (subcutaneously), once a week, in Lilly's trials. The Zepbound label says not to inject tirzepatide into a muscle or vein.

Morning or night? No retatrutide trial has tested time of day. Lilly Medical Information gives a time to peak of 12 to 72 hours after a dose and a half-life of about 6 days (how long it stays in your system), so keeping the same weekday matters more than the hour, and the Zepbound and Wegovy injection labels both allow any time of day. More on that in the best time to take retatrutide.

What it feels like, in trial terms, is less appetite and, for many people, nausea or diarrhea that bunches up in the weeks after each dose step (TRANSCEND-T2D-1 saw them mainly during escalation).