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Sema, Tirz and Reta decoded: every name, brand and nickname

Semaglutide, tirzepatide and retatrutide travel under a small blizzard of aliases: chemical names, brand names, lab codes, receptor shorthand and forum slang. If you have ever wondered what GLP-3 is, whether tirzepatide has other names, or why one vial gets called four different things, this page lines every label up in one place. It covers naming, receptor class and regulatory status only. It makes no claims about effects, and every vial we sell is for laboratory research only.

Snowman Research does not offer dosing information or usage guidance of any kind. Everything on this page is reference material about research products sold for laboratory research only.

Sema vs Tirz vs Reta at a glance
Sema (Semaglutide)Tirz (Tirzepatide)Reta (Retatrutide)
Short nameSemaTirz, TR (vial code)Reta, RT (vial code)
DeveloperNovo NordiskEli LillyEli Lilly
Development codeNN9535 (injectable program)[6]LY3298176[10]LY3437943[11]
Drug classGLP-1 receptor agonist[1]Dual GIP and GLP-1 receptor agonist[7]Triple GIP, GLP-1 and glucagon receptor agonist[11][12]
Receptors targeted1: GLP-12: GIP + GLP-13: GIP + GLP-1 + glucagon
What buyers often call itGLP-1, sema, "the Ozempic peptide"GLP-2, tirz, twincretin, "the Mounjaro peptide", "TR peptide", "King Kong" (media)[16]GLP-3, reta, triple G, triple agonist, "RT peptide", "Godzilla", "Godzilla Ozempic" (media)[16][17][18]
U.S. brand namesOzempic, Rybelsus, Wegovy[1][2][4]Mounjaro, Zepbound[7][8]None: no approved product[15]
FDA statusApproved since 2017 (first label: Ozempic)[1]Approved since 2022 (first label: Mounjaro)[7]Investigational, in phase 3 trials[13][15]
Molecular weight (FDA label)4113.58 g/mol, C187H291N45O59[1]4813.53 Da, C225H348N48O68; 39 amino acids[7]Not on any FDA label (investigational)
Vials we stockSemaglutide 5mgTirzepatide 5mg to 120mg (label code TR)Retatrutide 5mg to 60mg (label code RT)

Why one peptide wears so many names

Each of these molecules picks up names at different stages of its life. In the lab it gets a development code from the company that made it. Next comes an official generic name (the long "-glutide" or "-tide" word). If a regulator approves it, it gains one or more brand names, and a brand is tied to a specific product and indication rather than to the molecule. Along the way, buyers invent short names and slang that are quicker to type. Search engines treat every one of these as a separate query, which is why the same compound can be hard to look up.

Sema (Semaglutide): the GLP-1 receptor agonist

Semaglutide is Novo Nordisk's modified analog of the GLP-1 hormone. Its design adds a fatty-acid side chain so it binds to albumin, plus a substitution that protects it from the enzyme DPP-4[5]. It acts on a single receptor, GLP-1, which is why buyers so often shorten the name to plain "GLP-1".

Names you will run into:

  • Semaglutide: the generic name printed on every label.
  • Sema: the everyday short form.
  • NN9535: Novo Nordisk's code for its injectable semaglutide trials, visible in trial records such as SUSTAIN 6[6].
  • Ozempic: once-weekly injection, the first semaglutide label, approved in 2017 for type 2 diabetes[1].
  • Rybelsus: the tablet form, approved in 2019 for type 2 diabetes[2].
  • Wegovy: an injection approved in 2021 for chronic weight management[3], joined by Wegovy tablets on the December 2025 label[4].

Three brands, one active ingredient: the FDA labels for all of them list the same molecular formula[1][2][4].

Tirz (Tirzepatide): the dual agonist people call GLP-2

Tirzepatide is Eli Lilly's 39-amino-acid peptide built on the GIP sequence and modified with a C20 fatty diacid[7]. It activates two receptors, GIP and GLP-1, so the literature calls it a dual agonist; the nickname "twincretin" (two incretins in one molecule) turns up in both medical commentary and forums. During development it was known as LY3298176[10].

In buyer shorthand, tirzepatide is "GLP-2": the number counts the receptors it hits, one more than sema. If you want the receptor-accurate label alongside it, that is a dual GIP/GLP-1 receptor agonist. (Biology also has a natural gut hormone named GLP-2, which is a separate molecule, so a search for "GLP-2 peptide" can surface both.)

Brand names: Mounjaro, approved in May 2022 for type 2 diabetes[7], and Zepbound, approved in November 2023 for chronic weight management[8][9]. Both contain tirzepatide, which is why phrases like "Mounjaro peptide", "Zepbound peptide" or "tirz Mounjaro" show up in searches for the generic compound.

Outside the research market, the press has given tirzepatide one more nickname: the "King Kong" of the GLP-1s[16]. The story behind it is in the Godzilla section below.

On research vial labels, tirzepatide is usually shortened to TR, and that is the code on Snowman's vials too: a label reads, for example, "TR 10mg Research Only". So a TR peptide, a TR vial or a listing for TR 10mg or TR 5mg means tirzepatide.

Reta (Retatrutide): the triple G, a.k.a. GLP-3

Retatrutide, code LY3437943, is a single Lilly peptide designed to activate three receptors: GIP, GLP-1 and glucagon[11]. Researchers call it a triple hormone-receptor agonist[12], and buyers have shortened that to "triple G" (sometimes "GGG" or "triple agonist").

Following the same counting logic, buyers call retatrutide "GLP-3": three receptors, one step past tirz. There is no natural hormone called GLP-3, so the nickname always points back to this one compound; the receptor-accurate description is a GIP/GLP-1/glucagon triple agonist.

Retatrutide has no brand name. It is still investigational: phase 3 TRIUMPH results have begun appearing in journals[13], and Lilly states the molecule is not approved by the FDA or any other regulator[15]. Any product calling itself a "retatrutide brand" is using a label that does not exist yet.

Vial labels shorten retatrutide to RT, and Snowman's vials use the same code, for example "RT 10mg Research Only". A search for an RT peptide, an RT vial, RT 10mg or RT 5mg points to retatrutide. Don't mix the two up: TR is tirzepatide, RT is retatrutide.

Godzilla and King Kong: the media nicknames

Retatrutide's best-known headline name is "Godzilla", and some outlets stretch it to "Godzilla Ozempic". It traces back to a 2024 remark by University of Texas professor Julio Rosenstock, as reported by Dazed: "We know that tirzepatide (Mounjaro) is the King Kong of the GLP-1s. And when I look at retatrutide, I think that there is no question that Godzilla is smiling."[16]

The quote set the two Lilly molecules side by side as movie monsters: tirzepatide, the dual GIP/GLP-1 agonist, as King Kong, and retatrutide, which adds the glucagon receptor as a third target, as Godzilla. The label has stuck. The Guardian used it in a September 2026 headline[17], and BBC Science Focus wrote that retatrutide is nicknamed "Godzilla Ozempic"[18].

So if you see searches for a Godzilla peptide, retatrutide Godzilla or Godzilla Ozempic, they all mean the same compound: retatrutide, LY3437943, a.k.a. reta or GLP-3. These are media nicknames, not brand names. Retatrutide still has no approved product[15].

Misspellings and search variants

These names are long, and people type them fast. All of the following point to the same three compounds:

  • Semaglutide: semiglutide, semaglutid, semaglitide, simaglutide, semaglutyde, sema glutide.
  • Tirzepatide: tirzepatyde, tirzapatide, terzepatide, tirzepitide, trizepatide, tirzepatid.
  • Retatrutide: retatrutid, retatide, retatrudide, reditrutide, retatrutyde, retrutide.

Other languages spell the generic names their own way, too: semaglutida, tirzepatida and retatrutida in Spanish and Portuguese, or Semaglutid, Tirzepatid and Retatrutid in German. Our translated pages use the local spelling.

Compounded, brand-name or research-grade?

Three phrases get mixed up constantly, and they describe very different things:

  • Brand-name: an FDA-approved finished product, such as Ozempic or Mounjaro, made by the license holder.
  • Compounded: a version prepared by a pharmacy for an individual patient. The FDA notes that compounded drugs are not FDA-approved and are not reviewed for safety, effectiveness or quality before they are sold, and it states that retatrutide cannot be used in compounding under federal law[14].
  • Research-grade: raw lyophilized peptide sold for laboratory work, not as a medicine. This is the only kind Snowman sells.

A research vial is not a brand-name pen, a generic, or a compounded prescription, whatever nickname a forum gives it.

Seeing "acetate", "sodium" or "TFA" after a peptide name? Our base vs salt peptide guide explains what those salt forms mean and how they show up on labels.

How Snowman names these vials

On our shelf we pair the short name with the full one, for example Tirz (Tirzepatide) or Reta (Retatrutide), so you can match a forum nickname to the compound on the label without guessing. The printed vial labels are shorter still: our tirzepatide vials carry the code TR and our retatrutide vials carry RT, each with the fill size (for example "TR 10mg" or "RT 10mg"), while semaglutide is printed in full as "Semaglutide". Every vial is sold as a sealed, freeze-dried powder for in-vitro and laboratory research. The GLP-1 receptor agonist research shelf keeps all three together, and the tirzepatide and retatrutide family pages list every size we stock.

Quick answers

What is GLP-3? A buyer nickname for retatrutide, the GIP/GLP-1/glucagon triple agonist. It is not a separate hormone.

Is GLP-2 the same as tirzepatide? In buyer slang, yes: "GLP-2" means tirzepatide, the dual GIP/GLP-1 agonist. The natural hormone GLP-2 is a different molecule.

What do TR and RT mean on a vial? They are label codes: TR is tirzepatide and RT is retatrutide. Snowman's vials use both, so "TR 10mg" is a 10mg tirzepatide vial and "RT 10mg" is a 10mg retatrutide vial.

What are tirzepatide's other names? Tirz, TR (the vial code), LY3298176, twincretin, GLP-2, the media nickname "King Kong", and the brands Mounjaro and Zepbound.

Are Ozempic and Wegovy different drugs? They are different brands and products, but both contain semaglutide[1][4].

Why is retatrutide called Godzilla? It is a media nickname. It comes from a 2024 quote by Professor Julio Rosenstock that called tirzepatide the "King Kong" of the GLP-1s and retatrutide, the triple agonist, "Godzilla"[16]. "Godzilla peptide" and "Godzilla Ozempic" both mean retatrutide.

Does retatrutide have a brand name? Not yet. It is investigational and unapproved[15].

On our shelf

Sources

  1. OZEMPIC (semaglutide) injection, prescribing information. Initial U.S. approval 2017. Novo Nordisk; label revised December 2017. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/209637lbl.pdf
  2. RYBELSUS (semaglutide) tablets, prescribing information. Novo Nordisk; label revised September 2019. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/213051s000lbl.pdf
  3. WEGOVY (semaglutide) injection, prescribing information. Novo Nordisk; label revised June 2021. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/215256s000lbl.pdf
  4. WEGOVY (semaglutide) injection and tablets, prescribing information. Novo Nordisk; label revised December 2025. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/218316Orig1s000lbl.pdf
  5. Discovery of the Once-Weekly Glucagon-Like Peptide-1 (GLP-1) Analogue Semaglutide. J Med Chem. 2015;58(18):7370-80. PMID 26308095. https://pubmed.ncbi.nlm.nih.gov/26308095/
  6. SUSTAIN 6 trial record, sponsor study ID NN9535-3744 (NCT01720446). ClinicalTrials.gov, Novo Nordisk A/S. https://clinicaltrials.gov/study/NCT01720446
  7. MOUNJARO (tirzepatide) injection, prescribing information. Initial U.S. approval 2022. Eli Lilly; label revised May 2022. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/215866s000lbl.pdf
  8. ZEPBOUND (tirzepatide) injection, prescribing information. Eli Lilly; label revised November 2023. Drugs@FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/217806s000lbl.pdf
  9. FDA Approves New Medication for Chronic Weight Management. U.S. Food and Drug Administration press announcement, Nov 8, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-new-medication-chronic-weight-management
  10. LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: From discovery to clinical proof of concept. Mol Metab. 2018;18:3-14. PMID 30473097. https://pubmed.ncbi.nlm.nih.gov/30473097/
  11. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept. Cell Metab. 2022;34(9):1234-1247.e9. PMID 35985340. https://pubmed.ncbi.nlm.nih.gov/35985340/
  12. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. PMID 37366315. https://pubmed.ncbi.nlm.nih.gov/37366315/
  13. Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial. Lancet. 2026;408(10563):1455-1472. PMID 42810372. https://pubmed.ncbi.nlm.nih.gov/42810372/
  14. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. U.S. Food and Drug Administration web page (accessed Oct 17, 2026). https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
  15. Is retatrutide available in the consumer market? Lilly Medical Information, Eli Lilly and Company (last reviewed Aug 4, 2026). https://medical.lilly.com/us/products/answers/is-retatrutide-available-in-the-consumer-market-381272
  16. What is Retatrutide? The new 'Godzilla' weight-loss injection. Dazed, May 14, 2024 (quotes Prof. Julio Rosenstock). https://editors.dazeddigital.com/beauty/article/62610/1/what-is-retatrutide-the-new-godzilla-weight-loss-injection
  17. 'Godzilla' of weight-loss drugs could provide other important health benefits. The Guardian, Sep 29, 2026. https://www.theguardian.com/science/2026/sep/29/retatrutide-godzilla-of-weight-loss-drugs-other-health-benefits
  18. 'A really substantive jump': The most powerful weight-loss drug ever tested has arrived. BBC Science Focus Magazine, Sep 16, 2026. https://www.sciencefocus.com/the-human-body/retatrutide-godzilla-ozempic-glp1-weight-loss-2

For laboratory research use only. Not for human or veterinary use, not FDA-approved, and nothing on this page is medical advice. You must be 21 or older to purchase.