Retatrutide Brand Name: Are Retkouro and Retzoundi Real? (2026)

“There’s a long process to select that name.”
— Mike Mason, president of Lilly Diabetes and Obesity, on naming Zepbound, via Fierce Pharma

The short answer: There is no official retatrutide brand name yet. Retkouro and Retzoundi are real trademark applications Eli Lilly filed on April 23, 2024, but Lilly filed a batch of nine drug names that day, and nothing public ties these two to retatrutide.

Lilly has also filed newer names that echo the drug, such as Retanova in September 2026. Our read: expect the real name around approval, not before.

Lots of filings, no announcement. A trademark is a reservation, not a launch.

In this post you’ll learn what the Retkouro and Retzoundi filings actually say, why they don’t prove anything yet, how drug names really get picked, and when the retatrutide brand name is likely to appear. About 5 minutes.

Where Did “Retkouro” and “Retzoundi” Come From?

From a post on X on October 27, 2026, which said Retkouro and Retzoundi are the likely brand names for retatrutide, based on Lilly trademark filings. The post came from On The Pen, a GLP-1 news account, and it was shared with images of a branded pen and vial.

The trademark part checks out. The conclusion is a guess. And we could not find those pen and vial images in any Lilly or FDA material, so treat them as unofficial.

A name isn’t a launch date. A trademark filing is the cheapest step in a drug launch. Approval is the hard one.

Action item: When you see a “leaked” drug name, ask one question: did the company or the FDA say it? If not, it’s a guess.

Are Retkouro and Retzoundi Real Lilly Trademarks?

Yes. Both are pending U.S. trademark applications owned by Eli Lilly and Company, filed on April 23, 2024. Retkouro is serial number 98515518 and Retzoundi is 98515533, per Trademarkia’s copies of the USPTO records.

Both were filed on an “intent to use” basis, which means Lilly wasn’t using the names yet. Both are in class 5, pharmaceuticals. The goods listed are broad, a long list of conditions that starts with alopecia and Alzheimer’s disease, not a single weight-loss drug.

In October 2026, Lilly received a fourth extension of time on each to show the name is in use, per the same records. Neither is registered yet.

Action item: Want to check a rumored name yourself? Search it on the USPTO’s free trademark search and look at the owner, the filing date and the goods listed.

Why Doesn’t a Trademark Prove the Brand Name?

Because drug companies file many candidate names, and only one becomes the brand. On April 23, 2024, Lilly filed a batch of nine pharmaceutical trademarks, per Justia Trademarks:

Emwilzy, Orfyzent, Retkaytu, Retkouro, Senmounto, Valmounry, Zenmounto, Retzoundi and Xbountri

Three of those start with “RET.” Several echo other Lilly brands, like “MOUN” from Mounjaro in Senmounto and Zenmounto, and “BOUN” from Zepbound in Xbountri. That pattern is suggestive, but it’s our observation, not Lilly’s statement.

Lilly kept filing. Retahvera was filed on August 4, 2026, and Retanova and Onereta on September 2, 2026, all as intent-to-use drug names, per USPTO records for Retahvera, Retanova and Onereta. Those contain “Reta” outright, and they’re newer than the 2024 batch.

Action item: Don’t bet on one name. Our read: the newer “Reta” filings suggest the shortlist is still open.

How Does a Drug Get Its Brand Name?

The company proposes it, and the FDA has to accept it before approval. FDA guidance says requests for a name review should come no earlier than the end of Phase 2, and a company can submit up to two names at a time, a first choice and a backup, per the FDA’s guidance on proprietary name submissions.

Under the goals in that 2016 guidance, the FDA gives a tentative answer within 180 days during development, or within 90 days once the approval application is filed. The FDA checks that a name can’t be confused with another drug, which is a safety issue, not marketing.

Companies also test names with the public. For Zepbound, Lilly said the name tested well with consumers and healthcare professionals, per Fierce Pharma.

Action item: Remember that a name has to clear the FDA. Even Lilly’s first choice can be rejected.

When Will We Know the Retatrutide Brand Name?

Our read: most likely at FDA approval. Lilly plans to submit retatrutide to the FDA in the first quarter of 2027, per its September 29, 2026 release. Add the time for an FDA review, and a decision in late 2027 or 2028 is plausible. That’s our estimate, not Lilly’s.

That’s how Zepbound went: Lilly announced the name on November 8, 2023, after the FDA approved it for weight loss, per STAT. We track the timeline in When will retatrutide be available?

Action item: Search for “retatrutide FDA approval,” not a rumored brand name. The name will arrive with the decision.

Is It Safe to Buy “Retzoundi” or “Retkouro” Online?

No. Lilly sells no retatrutide product under any name, so anything sold online as Retzoundi, Retkouro or retatrutide isn’t Lilly’s drug. The FDA says retatrutide isn’t part of any approved drug, can’t be used in compounding, and has warned sellers marketing it “for research purposes” (FDA, Oct 1, 2026).

A rumored brand name can make a gray-market vial look official. A realistic pen image doesn’t change what’s inside it.

If you took a product sold as retatrutide and feel unwell, contact your doctor. Get urgent care for severe stomach pain, vomiting you can’t stop, fainting, or swelling of the face or throat.

Action item: If you’re curious about retatrutide, ask your doctor about clinical trials, not a website. See how it did against Ozempic while you wait.

Quick Answers

What is the retatrutide brand name? It doesn’t have one yet. Lilly hasn’t announced a name, and retatrutide isn’t approved, as of October 29, 2026.

Is Retzoundi the brand name for retatrutide? Not officially. Retzoundi is a pending Lilly trademark filed in April 2024 alongside eight other names, and nothing public links it to retatrutide.

Is Retkouro the brand name for retatrutide? Same answer: it’s a real, pending Lilly trademark from the same batch, not a confirmed name.

When will Lilly name retatrutide? Our read: most likely at FDA approval. Lilly plans to file in Q1 2027; a decision in late 2027 or 2028 is our estimate.

Who makes retatrutide? Eli Lilly, the company behind Mounjaro and Zepbound.

What This Means for You

✅ You know Retkouro and Retzoundi are real but unconfirmed

✅ You know Lilly filed a batch of nine names in one day, plus newer “Reta” names

✅ You know the FDA has to accept a drug’s name

✅ You know the real name will most likely come with approval (our read)

✅ You won’t trust a product because it carries a rumored name

The 5-Minute Version (Screenshot This)

Rumor: a viral Oct 27, 2026 post said Retkouro and Retzoundi are retatrutide’s likely brand names.
Fact: both are pending Lilly trademarks filed April 23, 2024, with seven other drug names the same day.
Newer filings: Retahvera (Aug 2026), Retanova and Onereta (Sep 2026).
Official status: no brand name announced; retatrutide isn’t approved.
Timing: FDA filing planned Q1 2027; name likely at approval, late 2027 or 2028 (our estimate).

Conclusion

The retatrutide brand name rumor rests on real paperwork and a guess. Retkouro and Retzoundi are genuine Lilly trademarks, but so are seven other names filed the same day and several newer “Reta” names. Until Lilly or the FDA says it, retatrutide doesn’t have a brand name.

Your one action today: if you see a product with a rumored name, skip it, and follow the FDA filing instead.

Want the science while you wait? Read what retatrutide did for sleep apnea.

So tell me: which name would you pick for retatrutide, and does a drug’s name change how you feel about taking it?