GLP-1 vs GLP-2: What Each Hormone Does and Which Drugs Target Them

GLP-1 and GLP-2 (glucagon-like peptide 1 and 2) are two different hormones with different jobs. GLP-1 mainly helps control blood sugar and appetite, while GLP-2 mainly helps the lining of the gut grow and absorb nutrients. Cells in your intestine called L cells make both from the same starting molecule, proglucagon, and release them together after you eat; each then acts on its own receptor, the docking site on cells that responds to it.^{1, 2, 3}

GLP-1 raises insulin and lowers glucagon after a meal, which keeps blood sugar from climbing too high, and it slows the stomach and helps you feel full.^{1, 2} Some medicines that act on its receptor, such as Ozempic and Mounjaro, are FDA-approved to treat type 2 diabetes as an add-on to diet and exercise. Others, such as Wegovy, Zepbound and Foundayo, are approved to help adults who have obesity, or overweight plus a weight-related health problem, lose weight and keep it off, alongside a reduced-calorie diet and more physical activity.^{4, 5, 6, 7, 8}

As of October 3, 2026, the only FDA-approved GLP-2 drug is teduglutide (Gattex).^{9, 10} It treats short bowel syndrome (SBS), in which a shortened or damaged small intestine cannot absorb enough nutrients from food, in adults and children 1 year and older who depend on IV nutrition or fluids (parenteral support).^{9, 11} No GLP-2 drug is approved for weight loss, and none has been proven to work for it in a late-stage (phase 3) trial.^{9, 12, 13}

Zepbound and Mounjaro, which both contain tirzepatide, are not GLP-2 drugs. Tirzepatide acts on the receptors for GLP-1 and for GIP (glucose-dependent insulinotropic polypeptide), another natural hormone.⁷ Some online sellers have put "GLP-2" on products they call tirzepatide, and in 2026 FDA told three of them that their products were unapproved drugs (details below).^{14, 15, 16} Both kinds of approved medicine carry serious warnings: see Gattex's and the GLP-1 medicines', with links to their FDA labels.

One gene, two hormones, two different jobs

Both hormones are cut from proglucagon inside L cells. GLP-1 is a chain of 30 amino acids. GLP-2 has 33 and is coded further along the same gene, after GLP-1.^{2, 3} Their jobs differ mainly because their receptors are found in different tissues:¹

Natural GLP-1 does not last long. An enzyme called DPP-4 breaks it down extremely quickly, even before it leaves the gut, so GLP-1 medicines such as semaglutide are built to resist that enzyme.^{2, 4} DPP-4 is also a key control on how active natural GLP-2 is, and teduglutide was developed as a modified GLP-2 that works with one injection a day.¹⁷

Are GLP-1 and GLP-2 peptides? Yes. A peptide is a short chain of amino acids, typically 2 to 50.¹⁸ GLP-1 and GLP-2 are peptide hormones, and semaglutide, tirzepatide and teduglutide are drugs built on the amino-acid sequences of natural hormones.^{2, 3, 5, 6, 9} "Peptide" names a kind of molecule, not a kind of treatment, so calling a product a peptide says nothing about whether it is approved or safe.

Is tirzepatide a GLP-2? Where the nickname comes from

No. According to the Zepbound label, tirzepatide selectively binds and activates two receptors, GIP and GLP-1, so it is a dual GIP and GLP-1 drug.^{5, 7} GLP-2 is the name of a separate gut hormone, not shorthand for "two receptors".³

Some online sellers use the numbers as nicknames anyway. In warning letters dated March 31 and August 24, 2026, FDA described three websites offering products they called tirzepatide under names such as "GLP-2 TRZ", "Tirzepatide (GLP-2 TRZ)" and "GLP-2 peptide". Two of them also sold an experimental drug as "GLP-3 RT".^{14, 15, 16}

FDA said the products were unapproved new drugs.^{14, 15, 16} Labels saying a product was for research use only or not for human use did not change that, FDA said, because the websites showed the products were meant for use in people.^{14, 15, 16}

That experimental drug acts on three receptors, for GIP, GLP-1 and glucagon, and is still being tested in phase 3 trials.^{19, 20} "GLP-3 RT" is the sellers' label for it, not the name of an approved medicine. FDA says the drug has not been found safe and effective for any condition, is not part of any FDA-approved drug and cannot be used in compounding (a pharmacy making a drug for one patient's prescription).²¹

The "GLP-2" label can hide a real risk. A product sold as "GLP-2" may contain tirzepatide, which acts on the GLP-1 receptor. Taking it with a "GLP-1" product could then mean using two GLP-1 drugs at once, something the Wegovy, Zepbound and Foundayo labels do not recommend (see the warnings below).^{6, 7, 8, 15}

FDA urges consumers not to buy semaglutide, tirzepatide or related drugs whose labels falsely say "for research purposes" or "not for human consumption", calling them of unknown quality and possibly harmful to health.²¹ It also points out that injected products bypass some of the body's defenses against toxins and germs.¹⁶

Before paying any seller, run through the seller checks on our compounded tirzepatide provider page, which also covers the legal rules for compounded drugs. If you already have a product like this, talk to your doctor about it, as FDA advises for any question about your medicines.²¹ If you have had a side effect or a quality problem, FDA also asks patients to report it to its MedWatch program.²¹

Teduglutide (Gattex), the only FDA-approved GLP-2 drug

FDA approved Gattex in December 2012. It treats adults and children 1 year and older with SBS who depend on parenteral support, meaning nutrition or fluids given into a vein.^{9, 22} SBS can be mild, moderate or severe, and long-lasting SBS is rare, because in most cases the intestine heals and adapts.¹¹

Teduglutide is a modified, lab-made version of GLP-2. It binds GLP-2 receptors on certain cells and nerves in the intestine, which then release local signaling molecules such as insulin-like growth factor 1.⁹ It is given as an injection under the skin once a day.⁹

Its main trial enrolled 86 adults who had relied on IV nutrition or fluids for at least a year; for 24 weeks, half took Gattex and half a placebo. At both week 20 and week 24, 63% of those on Gattex had cut their weekly IV volume by at least 20%, compared with 30% on placebo. By week 24, weekly IV volume had fallen by an average of 4.4 liters with Gattex, from about 12.9 liters at the start, compared with 2.3 liters with placebo.⁹

Crohn's disease was one of the reasons trial patients had lost part of their intestine, but Gattex is approved for SBS, not for Crohn's disease.⁹

Gattex's warnings and the checkups they require

The growth effect that helps a shortened bowel is also behind Gattex's first warning. Its label names no group that must never use it, but it lists these warnings and tests:⁹

• Faster growth of abnormal cells. Gattex can make abnormal cells already in the body grow faster, raising the risk that they become cancer. The label bases this on how the drug works and on tumors in rat and mouse studies, and intestinal polyps were found in its clinical trials.⁹ For people at higher risk of cancer, it should be used only if the benefits outweigh the risks. It is stopped if cancer of the bowel, liver, gallbladder or pancreas is found, and for other cancers the decision to continue weighs benefit and risk.⁹
• Scope exams and stool tests. Adults need a colonoscopy and an upper endoscopy (camera exams of the colon and of the upper digestive tract), with any polyps removed, within 6 months before starting. The exams are repeated after 1 year and then every 5 years or more often if needed, and the later checks can use other imaging instead. Children need a stool test for hidden blood within 6 months before starting and every year after, and a colonoscopy or sigmoidoscopy (a shorter scope of the lower colon) after 1 year and then every 5 years. In children, new or unexplained blood in the stool also calls for a colonoscopy or sigmoidoscopy and an upper endoscopy.⁹
• Bowel blockage. If the intestine or a stoma (a surgical opening for the bowel) becomes blocked, Gattex is paused while doctors check and treat it. Tell your healthcare provider right away about trouble having a bowel movement or passing gas, belly pain or swelling, nausea, vomiting, or swelling and blockage of a stoma opening.⁹
• Gallbladder and pancreas disease. Blood tests that check the gallbladder and pancreas (bilirubin, alkaline phosphatase, lipase and amylase) are done within 6 months before starting and at least every 6 months during treatment. Tell your healthcare provider right away about belly pain and tenderness, chills, fever, a change in your stools, nausea, vomiting, dark urine, or yellow skin or eyes.⁹
• Fluid overload. Because the gut absorbs more fluid, fluid overload and congestive heart failure occurred in its trials. When Gattex is stopped, fluid and electrolyte (body salt) levels are watched. Tell your healthcare provider right away about swelling in your feet and ankles, very fast weight gain (water weight) or trouble breathing.⁹
• Stronger effects from other pills. Gattex may increase how much of a medicine taken by mouth the body absorbs, so other drugs, such as benzodiazepines (a group of anxiety and sleep medicines), may need lower doses.⁹

The most common side effects, seen in 10% or more of patients, are belly pain, nausea, upper respiratory infections, a swollen belly, injection-site reactions, vomiting, fluid overload and allergic reactions.⁹ Breastfeeding is not recommended during treatment. Gattex's Medication Guide says it is not known whether the drug will harm an unborn baby and asks you to tell your healthcare provider right away if you become pregnant while using it.⁹

If you or your child depends on IV nutrition or fluids because of SBS, Gattex is a decision to make with the specialist who treats it, using the full Gattex label and Medication Guide.⁹

Other GLP-2 drugs are still in trials

Two long-acting GLP-2 drugs for SBS are in late-stage (phase 3) trials. Neither is FDA-approved:

• Glepaglutide (Zealand Pharma). In December 2024, FDA sent Zealand a complete response letter, which means it did not approve the application as submitted, and recommended another placebo-controlled trial.²³ That trial, EASE SBS 5, started on February 11, 2026, and is recruiting; the trial registry estimates that data for its main outcome will be collected by October 2028.²⁴ In Europe, the European Medicines Agency's expert committee recommended approving glepaglutide, under the name Zeydovio, for adults with SBS on September 17, 2026; the European Commission makes the final decision.²⁵
• Apraglutide (Ironwood Pharmaceuticals). In April 2025, Ironwood said that, based on talks with FDA, a confirmatory phase 3 trial is needed before it can seek approval. Ironwood says it started that trial, STARS-2, in June 2026.²⁶ The registry lists STARS-2 as recruiting and estimates that data for its main outcome will be collected by October 2028.²⁷

Can a GLP-2 drug help you lose weight?

Not on the evidence available on October 3, 2026:

• No approval and no obesity trials. Gattex is approved only for SBS in people who depend on parenteral support.⁹ A search of ClinicalTrials.gov, the National Library of Medicine's trial registry, found no registered study of teduglutide, glepaglutide or apraglutide in obesity, overweight or weight loss.¹²
• Natural GLP-2 did not curb appetite in a small study. In a 2003 placebo-controlled study of 18 healthy, normal-weight young adults, raising GLP-2 to the body's own levels for 4.5 hours did not change hunger, fullness or how much they ate at a meal. The study was small and short and did not test drug doses or people with obesity.²⁸
• A combined GLP-1 and GLP-2 drug has only early-stage results. Dapiglutide acts on both receptors. It was designed so that its GLP-1 part would drive weight loss and its GLP-2 part would strengthen the gut barrier and reduce inflammation.^{23, 29} In the one peer-reviewed placebo-controlled trial we found, 54 adults with obesity were randomly assigned to one of two doses or to placebo for 12 weeks, with no diet program. Weight fell by an average of 2.1% more on the higher of its two doses than on placebo, a gap small enough to be due to chance (not statistically significant), and the lower dose did not differ significantly from placebo either.²⁹ Zealand Pharma, which was developing it, calls the doses tested low doses, and the trial's authors say the results support testing higher doses in larger and longer studies.^{23, 29} A registry search finds no dapiglutide study beyond phase 2.¹³
• Its developer paused it for portfolio reasons. In November 2025, Zealand reported that development of dapiglutide "has been paused as part of active portfolio management, focusing investments on programs with the greatest potential for clinical differentiation and long-term value creation." It had planned a phase 2b trial in 2025.²³ Dapiglutide is an experimental drug, not an approved medicine.^{13, 23}

The GLP-1 medicines approved for weight management include Wegovy (semaglutide, as an injection or a tablet), Zepbound (tirzepatide) and Foundayo (orforglipron, a once-daily tablet). Each is approved, with a reduced-calorie diet and more physical activity, for adults who have obesity, or who have overweight along with a weight-related health problem, to reduce excess weight and keep it down over the long term.^{6, 7, 8} In Zepbound's main weight-loss trial, which enrolled adults, obesity was a BMI (body mass index) of 30 or above, and overweight was a BMI of at least 27 but under 30 together with at least one weight-related health problem, such as high blood pressure, abnormal cholesterol or sleep apnea.⁷

Of the three, only Wegovy injection is also approved for children: those 12 and older with obesity. Its trial in that age group enrolled children whose BMI put them at or above the 95th percentile for children of the same age and sex.⁶ All three carry the warnings summarized in the risks section below.

Ozempic (semaglutide) and Mounjaro (tirzepatide) are approved to improve blood sugar control, together with diet and exercise, in adults with type 2 diabetes (Mounjaro also in children 10 and older); neither is approved for weight loss.^{4, 5} Using any of these drugs outside its approved uses is off-label. If your situation doesn't match one of those uses, start with your own doctor, before PlexusDx or any other online seller of GLP-1 medicines. Our page on GLP-1 medicines when your weight is below the approved ranges goes through that situation.

For how much weight people lose on these medicines, and how fast, see our tirzepatide weight-loss timeline. For what they cost, see our GLP-1 prices without insurance.

Taking a GLP-1 and a GLP-2 medicine together

No FDA-approved product combines the two. Gattex, the only FDA-approved GLP-2 drug, contains teduglutide alone, and the one combined GLP-1 and GLP-2 drug we found tested for weight loss, dapiglutide, is experimental and has only early-stage results (see above).^{9, 10, 13} The approved drugs also treat different conditions: obesity and diabetes for the GLP-1 drugs, SBS for Gattex. Using Gattex for weight loss or general gut health would be off-label, and its growth warnings would still apply.^{4, 5, 7, 9}

If you see a product sold as a GLP-1 and GLP-2 blend, it is not an FDA-approved drug. If it was compounded, FDA did not review it for safety, effectiveness or quality before it was sold. FDA puts it plainly: compounded drugs "should only be used in patients whose medical needs cannot be met by an FDA-approved drug."²¹ If you have SBS and are also offered a GLP-1 medicine, decide with the doctors who treat you; this is not a combination to put together on your own.

Risks that come with GLP-1 medicines

The five approved GLP-1 medicines named on this page carry serious warnings of their own, and two kinds echo Gattex's: gallbladder and pancreas problems, and effects on other pills.^{4, 5, 6, 7, 8, 9} Talk them over with a prescriber before you start. The emergency signs below are the exception: act on those right away instead of waiting for an appointment.

• Do not double up. The Wegovy, Zepbound and Foundayo labels advise against using the drug with any other GLP-1 medicine, and that includes compounded semaglutide or tirzepatide, which are not FDA-approved.²¹ Wegovy's label names "other semaglutide-containing products" and Zepbound's "other tirzepatide-containing products". A product sold as "GLP-2" may contain tirzepatide, which would make it another one (see above).^{6, 7, 8}
• Thyroid tumors. All five labels lead with a boxed warning about thyroid C-cell tumors. Semaglutide and tirzepatide caused these tumors in rodents. Foundayo's label says orforglipron is not active in rats or mice and did not produce tumors in rodents. Orforglipron does act on the human GLP-1 receptor, though, and Foundayo's Medication Guide says medicines that work like it caused thyroid tumors in rodent studies. Whether any of the five causes them in people, including the thyroid cancer medullary thyroid carcinoma (MTC), has not been determined. Report a neck lump or swelling, hoarseness, trouble swallowing or breathlessness to your prescriber; the Medication Guides call these possible signs of thyroid cancer.^{4, 5, 6, 7, 8} If your thyroid has been removed, see our page on GLP-1 medicines after a thyroidectomy.
• Who must not use them. None of the five may be used by someone with a personal or family history of MTC, by anyone with multiple endocrine neoplasia syndrome type 2 (MEN 2), or by anyone known to be seriously allergic to the drug or one of its ingredients. The labels also advise against all five in severe gastroparesis (very slow stomach emptying), and against Foundayo in severe liver impairment.^{4, 5, 6, 7, 8}
• Gallbladder and pancreas, as with Gattex. Acute gallbladder disease, such as gallstones, an inflamed gallbladder or gallbladder removal, was reported more often on these medicines than on placebo in their trials. Pancreatitis, an inflamed pancreas, has been reported, with severe cases, some fatal, among drugs of this type. Stop the medicine and phone your prescriber right away for severe pain in your stomach area that won't go away, with or without vomiting, and perhaps spreading to your back. Call your prescriber right away, too, for pain in the upper belly, fever, yellow skin or eyes, or stools the color of clay.^{4, 5, 6, 7, 8}
• Other pills, as with Gattex. Gattex can increase how much of a pill the body absorbs. The GLP-1 medicines slow the stomach instead, which all five labels say may change how well other pills are absorbed.^{4, 5, 6, 7, 8, 9}
• Birth-control pills. The slower stomach can make birth-control pills less reliable. The Zepbound and Mounjaro labels tell users to move to a non-pill method, or to back the pill up with a barrier method, during the first 4 weeks and during the 4 weeks following each step up in dose. Foundayo's label gives that advice with 30-day periods and recommends effective birth control throughout treatment.^{5, 7, 8}
• Fluids and kidneys. Nausea, vomiting or diarrhea can dehydrate you, and kidney damage, in some cases requiring dialysis, has been reported, usually in people who had lost fluids that way. Keep drinking fluids, tell your prescriber if stomach problems become severe or keep going, and call right away if vomiting or diarrhea won't stop. Gattex's fluid warning is the reverse: fluid overload from absorbing too much.^{4, 5, 6, 7, 8, 9}
• Blood sugar. Low blood sugar is possible with all five and most likely for people also using insulin or a sulfonylurea, a pill that prompts the pancreas to release more insulin. The Wegovy, Zepbound and Foundayo labels also record it in adults who do not have type 2 diabetes. Before starting, ask how to recognize and handle it. Warning signs include dizziness, sweating, confusion, blurred vision, shakiness and a fast heartbeat.^{4, 5, 6, 7, 8}
• Serious allergy. Serious allergic reactions, including anaphylaxis (a severe whole-body reaction) and angioedema (deep swelling under the skin), have been reported. Stop the medicine and get medical help immediately if your throat, tongue, lips or face swell, if breathing or swallowing becomes hard, or if you get a severe rash or itching, feel faint or dizzy, or notice your heart racing.^{4, 5, 6, 7, 8}
• Pregnancy. All five labels flag a possible risk to an unborn baby. Zepbound and Foundayo are stopped once a pregnancy is recognized, as is Wegovy taken for weight or heart risk, and the Wegovy and Ozempic labels call for stopping at least 2 months before a planned pregnancy. Mounjaro's and Ozempic's labels allow use during pregnancy only when the possible benefit is judged to justify the possible risk to the baby. A pregnancy while on either one is a reason to call your prescriber promptly, not to stop or carry on alone. Breastfeeding during treatment is not recommended with Wegovy tablets or with Foundayo.^{4, 5, 6, 7, 8}

These are not all the risks. Some of the labels also cover, for example, diabetic eye disease, a faster resting heart rate, and interactions with specific medicines such as warfarin and levothyroxine. They also warn about breathing food or liquid into the lungs under anesthesia or deep sedation, so tell each doctor and dentist treating you that you take one of these medicines before any planned procedure.^{4, 5, 6, 7, 8} Each drug's full label and Medication Guide is on DailyMed: Wegovy, Ozempic, Zepbound, Mounjaro and Foundayo.

Sources

1. Review article: a comparison of glucagon-like peptides 1 and 2, Janssen P, Rotondo A, Mulé F, Tack J, Alimentary Pharmacology & Therapeutics, 2013 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
2. The physiology of glucagon-like peptide 1, Holst JJ, Physiological Reviews, 2007 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
3. Glucagon-like peptide 2, Drucker DJ, The Journal of Clinical Endocrinology & Metabolism, 2001 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
4. OZEMPIC (semaglutide) injection: prescribing information and Medication Guide (revised 5/2026), Novo Nordisk, via DailyMed, National Library of Medicine, accessed October 4, 2026.
5. MOUNJARO (tirzepatide) injection: prescribing information and Medication Guide (revised 8/2026), Eli Lilly and Company, via DailyMed, National Library of Medicine, accessed October 4, 2026.
6. WEGOVY (semaglutide) injection and tablets: prescribing information and Medication Guide (revised 6/2026), Novo Nordisk, via DailyMed, National Library of Medicine, accessed October 4, 2026.
7. ZEPBOUND (tirzepatide) injection: prescribing information and Medication Guide (revised 8/2026), Eli Lilly and Company, via DailyMed, National Library of Medicine, accessed October 4, 2026.
8. FOUNDAYO (orforglipron) tablets: prescribing information and Medication Guide (revised 7/2026), Eli Lilly and Company, via DailyMed, National Library of Medicine, accessed October 4, 2026.
9. GATTEX (teduglutide) for injection: prescribing information and Medication Guide (revised 9/2025), Takeda Pharmaceuticals America, via DailyMed, National Library of Medicine, accessed October 4, 2026.
10. openFDA Drugs@FDA data: search for teduglutide (run October 4, 2026), U.S. Food and Drug Administration, accessed October 4, 2026.
11. Definition & Facts for Short Bowel Syndrome, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, accessed October 4, 2026.
12. ClinicalTrials.gov search: teduglutide, glepaglutide or apraglutide, in obesity, overweight or weight loss (run October 4, 2026), ClinicalTrials.gov, National Library of Medicine, accessed October 4, 2026.
13. ClinicalTrials.gov search: dapiglutide (also searched by its code, ZP7570) (run October 4, 2026), ClinicalTrials.gov, National Library of Medicine, accessed October 4, 2026.
14. Mile High Compounds LLC, MARCS-CMS 721600 (warning letter, March 31, 2026), U.S. Food and Drug Administration, accessed October 4, 2026.
15. TXP Innovations LLC dba Tex Peptides, MARCS-CMS 735067 (warning letter, August 24, 2026), U.S. Food and Drug Administration, accessed October 4, 2026.
16. Gram Peptides, MARCS-CMS 721806 (warning letter, March 31, 2026), U.S. Food and Drug Administration, accessed October 4, 2026.
17. The Discovery of GLP-2 and Development of Teduglutide for Short Bowel Syndrome, Drucker DJ, ACS Pharmacology & Translational Science, 2019 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
18. Peptide (Talking Glossary of Genomic and Genetic Terms), National Human Genome Research Institute, National Institutes of Health, accessed October 4, 2026.
19. [Phase 3 obesity trial of a triple hormone receptor agonist], Jastreboff AM, et al., New England Journal of Medicine, published online September 29, 2026 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
20. ClinicalTrials.gov search: phase 3 studies of the experimental three-receptor drug (run October 4, 2026), ClinicalTrials.gov, National Library of Medicine, accessed October 4, 2026.
21. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (content current as of 10/01/2026), U.S. Food and Drug Administration, accessed October 4, 2026.
22. Drugs@FDA: GATTEX KIT, New Drug Application 203441, U.S. Food and Drug Administration, accessed October 4, 2026.
23. Zealand Pharma Announces Financial Results for the First Nine Months of 2025 (company announcement No. 23/2025, November 13, 2025), Zealand Pharma A/S, ESEF filing via filings.xbrl.org, accessed October 4, 2026.
24. Efficacy And Safety Evaluation of Glepaglutide in Treatment of SBS (EASE SBS 5), NCT07197944, ClinicalTrials.gov, National Library of Medicine, accessed October 4, 2026.
25. Zeydovio (glepaglutide): opinion, European Medicines Agency, page last updated September 18, 2026, accessed October 4, 2026.
26. Ironwood Pharmaceuticals, Inc., Form 10-Q for the quarter ended June 30, 2026 (filed August 6, 2026), U.S. Securities and Exchange Commission (EDGAR), accessed October 3, 2026.
27. A Study to Investigate the Efficacy and Safety of Apraglutide Compared With Placebo in Adult Participants With SBS-IF (STARS-2), NCT07742735, ClinicalTrials.gov, National Library of Medicine, accessed October 4, 2026.
28. No effect of physiological concentrations of glucagon-like peptide-2 on appetite and energy intake in normal weight subjects, Sørensen LB, Flint A, Raben A, Hartmann B, Holst JJ, Astrup A, International Journal of Obesity, 2003 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.
29. Dapiglutide, a dual GLP-1 and GLP-2 receptor agonist, for obesity: a randomised, double-blind, placebo-controlled parallel-group, proof-of-concept trial, Nielsen CK, et al., eClinicalMedicine, published February 21, 2026 (abstract on PubMed, National Library of Medicine), accessed October 4, 2026.

How we made this page

An earlier PlexusDx post on this subject covered the two hormones in a few lines, then promoted a PlexusDx genetic test, with claims about what certain gene variants do that no source we could find supports, and linked to PlexusDx products. None of its text, claims or links was kept.

For this version, AI tools gathered the documents in the sources list on October 3 and 4, 2026. They include the FDA labels for Gattex and the five GLP-1 medicines named here, FDA's approval records for teduglutide, its page on unapproved GLP-1 drugs and three of its 2026 warning letters. They also include ClinicalTrials.gov records and searches, Zealand Pharma's and Ironwood's own filings, the European Medicines Agency's opinion page for glepaglutide, seven journal articles and two NIH pages. From them, the AI wrote the explanations, the comparison table and the warning summaries. No single source says which GLP-2 drugs are approved, which are stalled and whether any has been tried for weight loss. To answer that, the AI read Gattex's label, FDA's approval database, the trial registry, Europe's regulator and the companies' filings side by side.

AI tools matched each statement to the source it cites. A script then confirmed that the words of every quotation in our evidence file are found in the copy of its source that we downloaded on October 3 or 4, 2026. Three AI reviewers read the draft on their own: one checked its facts, medical statements and regulatory claims against the sources, one read it as a newcomer to the topic would, and one checked what it says about PlexusDx. The AI editor revised the draft to answer what they found. After that, an AI reviewer that came to the page with no knowledge of its earlier drafts read it and checked a sample of its claims against the live sources; a final AI check covered the edits made afterward. None of this replaces a physician's or a lawyer's own review of the page.

PlexusDx sells compounded GLP-1 treatment, so we have a financial interest in this topic. See our editorial policy.

On October 19, 2026, Jay Hastings reviewed and approved this version. Dr. Asad K. Niazi, MD, MPH, reviewed the medical content on October 17, 2026. He is co-founder and CEO of Lone Star Virtual Health, the company that provides PlexusDx's prescribing clinicians, so he has a business relationship with PlexusDx.