Retzoundi and Retkouro: what the Lilly trademark filings show

The four names in the USPTO record

The USPTO publishes the status of every trademark application in a public database called Trademark Status and Document Retrieval, or TSDR. The Atlas read the four records below on October 28, 2026 (Retzoundi) (Retkouro) (Senmounto) (Emwilzy). Eli Lilly and Company is the applicant on all four.

All four were filed on April 23, 2024, as plain words with no logo (the USPTO calls this a standard character mark), under the heading for pharmaceutical preparations (class 5). All four were filed on an "intent to use" basis, which means Lilly said it intends to use the name and had not yet done so.

Read from the USPTO TSDR record for each serial number on October 28, 2026. "Under examination" is the USPTO's label for a live application that has been assigned to an examiner. It does not mean a regulator is reviewing a medicine.

What the records say about the medicine, and what they leave out

Each record lists the goods as pharmaceutical preparations "for the treatment of" a long run of conditions. The list on the three live records includes diabetes and obesity. It also includes Alzheimer's disease, cancer, heart failure, kidney and liver diseases, migraines and many others (example record). The list on Emwilzy's record is a little longer.

A description that broad cannot tell you which medicine a name is meant for, or how many. None of the four records names a medicine, a drug code or an ingredient. That is why the Atlas does not say that any of these names belongs to retatrutide, orforglipron or any other medicine.

Where the retatrutide link comes from

Posts on Reddit, X and Instagram have said that Retzoundi and Retkouro could be the brand names for retatrutide, the weekly triple-agonist injection Lilly is testing. The posts point to the trademark filings as the reason. The Atlas found no USPTO record, Lilly release or regulator page that connects either name to retatrutide. Lilly's own October 28, 2026 announcement of the TRANSCEND-T2D-2 results calls the drug only retatrutide (Lilly release).

The guess is not unreasonable. Lilly will need a brand name for each new medicine it takes to market, and it holds names it has not used. It is still a guess. A company can reserve a name years before choosing a medicine for it, can later use it for another product, and can drop it. Emwilzy, filed the same day, was dropped.

What the extensions do and do not tell you

A trademark filed on an intent-to-use basis moves through four steps. The USPTO examines it and publishes it so others can object. If nobody does, it issues a notice of allowance. The applicant then has six months to file a statement of use, which shows the name is really in use. If it is not ready, it can ask for more time (USPTO).

The USPTO allows five extension requests in all, each for six months, up to 36 months after the notice of allowance. For a notice dated November 12, 2024, that outer limit is November 2027. The records show four extensions granted, in April 2025, October 2025, August 2026 and October 2026. The records show no statement of use filed for any of the three names.

Asking for an extension means Lilly still wants the name. It does not say that a launch is near, or which product the name is for. The Atlas found no statement from Lilly that explains the extensions.

Where retatrutide stands

Retatrutide is investigational and is not approved anywhere. Lilly has reported phase 3 results in obesity, sleep apnea and type 2 diabetes, and has said it plans to submit the medicine to the FDA in the first quarter of 2027 (Lilly release). See the retatrutide page for the trials and the news page for the latest announcement.

In the United States the FDA evaluates a proposed brand name for confusion with other drug names (FDA guidance). Retatrutide has not reached the approval stage, and the Atlas found no Lilly or FDA statement that names a brand for it.

Other Lilly names that people mix up

Several kinds of name appear in searches about Lilly's weight-loss pipeline. They are not interchangeable.

A trademark application is a claim to a name. It is not an announcement of a product, and it is not an approval.

How to check the records yourself

Anyone can open a trademark record. Go to the USPTO's TSDR site and enter the serial number: 98515533 for Retzoundi, 98515518 for Retkouro, 98515527 for Senmounto and 98515512 for Emwilzy. The Atlas looked only at U.S. records. It did not check whether Lilly filed the same names in Europe, Japan or elsewhere. For another reading of the same records, see the PeptideBlog.net write-up.

A statement of use, a registration, or a new Lilly filing would show up there first. If Lilly announces a brand name, the announcement and the FDA approval record are the sources that matter. The Atlas will name the source and the date when that happens.

Quick answers

Is Retzoundi the brand name for retatrutide?

Not confirmed. Retzoundi is a trademark application filed by Eli Lilly and Company on April 23, 2024. The USPTO record does not name a medicine, and no Lilly release the Atlas read gives retatrutide a brand name. Posts online suggest a link. They give no source beyond the filing itself.

Is Retkouro the brand name for retatrutide?

Not confirmed. Retkouro is also a live Lilly trademark application, filed the same day as Retzoundi. Its record lists the same kind of broad list of conditions and names no medicine.

What is Senmounto?

A third live Lilly trademark application, filed on April 23, 2024 and listed by the USPTO as live. Like the other two, its record names no medicine and lists the same broad run of conditions. The Atlas found no source that says what it will be used for.

What happened to Emwilzy?

Emwilzy was filed the same day as the other three. Lilly filed an express abandonment on October 8, 2024, after the application was published, and the USPTO lists it as abandoned. The record does not give a reason.

Does a trademark filing mean Lilly will launch a medicine soon?

No. A company can file for a name long before it has a medicine to use it on. For these three names Lilly has now asked for four extensions of time to file proof of use, and the rules allow one more. That shows Lilly is keeping the names. It does not give a launch date.

Can I buy Retzoundi or Retkouro?

No approved product has either name. Retatrutide is not approved anywhere, and products sold online as retatrutide, or under names claimed to be retatrutide brands, have not been reviewed by the FDA. See the retatrutide page for the approval status.

When might retatrutide be approved?

Lilly has said it plans to submit retatrutide to the FDA in the first quarter of 2027. An FDA decision comes after the submission, and no decision date has been announced. Retatrutide has no approved use today.

Where can I read about Lilly's other codes and names?

The Lilly LY numbers guide covers the development codes, the LY4086940 page covers Lilly's oral compound with no public name, and the brand and generic names page covers names on approved medicines.

What is still unknown

• Which medicine, or medicines, Lilly intends each of the three live names for. None of the USPTO records says.
• Whether any of the names is meant for retatrutide. The link comes from posts online, not from a record.
• Why Lilly abandoned Emwilzy, and why it kept the other three.
• Whether Lilly filed the same names outside the United States. The Atlas read only the USPTO records.
• When Lilly will name a brand for any new medicine. Lilly has announced no brand name for retatrutide.