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Weight loss · Evidence tier A · #2 in test requests

Tirzepatide

LY3298176 (Eli Lilly development code) · Mounjaro (brand name; type 2 diabetes and heart-risk reduction) · Zepbound (brand name; weight loss and sleep apnea) · GLP-2 T, GLP-2 Tirz (vendor product names quoted in FDA warning letters; unrelated to the hormone GLP-2) · T-30, G2-TRZ, GLP-2 (vendor code names; our inference from vendor listings)

Tirzepatide is a weekly injection for weight loss and type 2 diabetes, sold as Zepbound and Mounjaro15. Trials show large weight loss2, but “research” vials are illegal to sell for human use and often fail tests34.

Last reviewed · First published · 55 sources · 30 min read · By the Pinc Peptide editors

Illustration: a glass vial with a pink label reading Tirzepatide
Illustration, not a real product: an empty glass vial (photo: Missouri Historical Society, public domain) with our label. See every vial.

Quick answers

What is it?
A weekly injection from Eli Lilly, sold as Zepbound for weight loss and Mounjaro for type 2 diabetes15. This lab-made peptide acts like two gut hormones, GIP and GLP-1, and makes people eat less1.
Does it work?
Yes, in large trials. On the top dose, people lost 20.9% of their weight on average over 72 weeks, versus 3.1% on placebo2. It beat semaglutide for weight loss in a head-to-head trial8. Weight tends to return after stopping9.
Is it safe?
It has known risks. Nausea, diarrhea, vomiting and constipation are common, mostly while the dose is being raised12. It caused thyroid tumors in rats; the risk in people is unknown1. The label also warns of an inflamed pancreas and gallbladder disease1.
Is it legal?
Yes, with a prescription, as Zepbound or Mounjaro5. US pharmacies may no longer make routine copies, because the shortage is over10. Selling “research” vials for human use is illegal in the US345. Not banned in sport3335.
What is in the vials?
Not always as labeled. As of 30 September 2026, 59 of Finnrick’s latest 196 completed tests failed4. Two fake pens detained in Ireland in 2025 held insulin41. Lilly scientists found an impurity of unknown effect in pharmacy-made mixes with vitamin B1240.

What it is

Tirzepatide is a synthetic peptide that activates the receptors for two gut hormones, GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1)1. GLP-1 helps regulate appetite and calorie intake, and nonclinical (lab and animal) studies suggest GIP may add to that effect1. Tirzepatide lowers calorie intake, boosts insulin release when blood sugar is raised, lowers glucagon and slows stomach emptying1. A C20 fatty-acid chain makes it bind to albumin in the blood, which gives it a half-life of about 5 to 6 days, so it is injected under the skin once a week1.

Eli Lilly developed tirzepatide under the code LY3298176 and published its discovery and first human studies in 201811. It is built on the natural GIP sequence1. FDA approved it as Mounjaro on 13 May 2022 and as Zepbound on 8 November 20235, and the EU authorized Mounjaro on 15 September 202212.

Benefits: what the research shows

Tirzepatide has been tested in large, controlled human trials, and the main ones were funded by Lilly215. In SURMOUNT-1 (2,539 adults with obesity or overweight, without diabetes), weekly 5, 10 or 15 mg cut weight by 15.0%, 19.5% and 20.9% at 72 weeks versus 3.1% on placebo, by the treatment-regimen estimand, which counts people who stopped the drug2. Among the 1,032 participants who also had prediabetes, losses of 12.3% to 19.7% were sustained at 176 weeks, and 1.3% developed type 2 diabetes versus 13.3% on placebo16. In an open-label head-to-head trial (SURMOUNT-5, 751 adults), weight fell 20.2% with tirzepatide versus 13.7% with semaglutide at 72 weeks8. In SURMOUNT-4, people switched to placebo after 36 weeks on tirzepatide gained 14.0% in weight over the next 52 weeks, while those who continued lost a further 5.5%9. Beyond weight: in moderate-to-severe obstructive sleep apnea with obesity (SURMOUNT-OSA), breathing interruptions fell by 25.3 and 29.3 events per hour at 52 weeks versus 5.3 and 5.5 on placebo17. In 13,299 adults with type 2 diabetes and atherosclerotic cardiovascular disease (SURPASS-CVOT), tirzepatide was noninferior to dulaglutide, an older GLP-1 drug with proven heart benefit, for heart attack, stroke or cardiovascular death (hazard ratio 0.92, 95.3% CI 0.83 to 1.01), but it was not shown to be better15. In heart failure with preserved ejection fraction and obesity (SUMMIT, 731 adults), it cut the combined rate of cardiovascular death or worsening heart failure (9.9% vs 15.3%), driven by fewer heart-failure events; cardiovascular deaths were few and not reduced18. Fatty liver disease with fibrosis (MASH) has only Phase 2 data (190 patients): MASH resolved without worsening fibrosis in 44% to 62% at 52 weeks versus 10% on placebo19. A 15,374-person trial of deaths and heart events in obesity (SURMOUNT-MMO) is still running, with primary completion estimated for October 202720. We found no published trial of research-labeled or compounded tirzepatide. A registered observational study with compounded tirzepatide groups, one of them on a “microdose” plan, had not started recruiting on 8 October 202655. High-quality evidence for “microdosing” is essentially absent21.

Key human studies

StudyDesignPeopleDose and routeResult
Jastreboff et al., N Engl J Med 2022 (SURMOUNT-1)2PubMed · DOI · NCT04184622 Phase 3 RCT, double-blind, placebo-controlled, 72 weeks including a 20-week dose escalation; adults with BMI 30 or more, or 27 or more with a weight-related complication, without diabetes 2,539 5, 10 or 15 mg subcutaneous once weekly Weight change -15.0%, -19.5% and -20.9% vs -3.1% on placebo (treatment-regimen estimand); 20% or more loss in 50% (10 mg) and 57% (15 mg) vs 3%2
Aronne et al., N Engl J Med 2025 (SURMOUNT-5)8PubMed · DOI · NCT05822830 Phase 3b RCT, open-label, tirzepatide vs semaglutide, 72 weeks; adults with obesity, without type 2 diabetes 751 Maximum tolerated dose, subcutaneous once weekly: tirzepatide 10 or 15 mg vs semaglutide 1.7 or 2.4 mg Weight change -20.2% vs -13.7%; waist -18.4 vs -13.0 cm (both P<0.001)8
Aronne et al., JAMA 2024 (SURMOUNT-4)9PubMed · DOI · NCT04660643 Phase 3 randomized withdrawal trial: 36-week open-label lead-in (783 adults), then 52 weeks double-blind of continued tirzepatide vs placebo; obesity or overweight, without diabetes 670 Maximum tolerated dose (10 or 15 mg) subcutaneous once weekly After a mean 20.9% loss in the lead-in, weight changed -5.5% with continued tirzepatide vs +14.0% after switching to placebo (weeks 36 to 88)9
Malhotra et al., N Engl J Med 2024 (SURMOUNT-OSA)17PubMed · DOI · NCT05412004 Two Phase 3 RCTs, double-blind, placebo-controlled, 52 weeks; adults with moderate-to-severe obstructive sleep apnea and obesity, not using (trial 1) or using (trial 2) PAP therapy 469 Maximum tolerated dose (10 or 15 mg) subcutaneous once weekly Apnea-hypopnea index change -25.3 vs -5.3 events per hour (trial 1) and -29.3 vs -5.5 (trial 2)17; 469 randomized across both trials6
Nicholls et al., N Engl J Med 2025 (SURPASS-CVOT)15PubMed · DOI · NCT04255433 Phase 3 RCT, double-blind, active-comparator noninferiority trial vs dulaglutide; adults with type 2 diabetes and atherosclerotic cardiovascular disease; 13,299 randomized, 13,165 analyzed 13,299 Tirzepatide up to 15 mg vs dulaglutide 1.5 mg, subcutaneous once weekly Cardiovascular death, heart attack or stroke: 12.2% vs 13.1% (hazard ratio 0.92, 95.3% CI 0.83 to 1.01); noninferior (P=0.003), not superior (P=0.09)15; median follow-up 210.1 weeks, per Lilly22
Packer et al., N Engl J Med 2025 (SUMMIT)18PubMed · DOI · NCT04847557 Phase 3 RCT, double-blind, placebo-controlled; heart failure with ejection fraction of 50% or more and BMI 30 or more; median follow-up 104 weeks 731 Up to 15 mg subcutaneous once weekly Cardiovascular death or worsening heart failure 9.9% vs 15.3% (hazard ratio 0.62, 95% CI 0.41 to 0.95); cardiovascular death 2.2% vs 1.4% (hazard ratio 1.58, 95% CI 0.52 to 4.83)18

Doses studied

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Zepbound label (weight loss and sleep apnea): start at 2.5 mg injected under the skin once weekly for 4 weeks, then increase in 2.5 mg steps, at least 4 weeks apart, until the maintenance dose is reached. Maintenance is 5, 10 or 15 mg weekly for weight (10 or 15 mg for sleep apnea); 2.5 mg is for starting only, and the maximum is 15 mg weekly1. Mounjaro label (type 2 diabetes): start at 2.5 mg weekly and increase in 2.5 mg steps after at least 4 weeks if needed; maximum 15 mg weekly in adults and 10 mg in children 10 and older23. Since 27 August 2026 the Mounjaro label allows 2.5 mg for ongoing blood sugar control7. The trials used the same range: fixed 5, 10 or 15 mg weekly in SURMOUNT-1, and the maximum tolerated dose of 10 or 15 mg, or up to 15 mg, in the sleep apnea, heart and heart-failure trials2151718. Phase 1 tested single doses of 0.25 to 8 mg, 4-week courses of 0.5 to 10 mg in healthy volunteers and 0.5 to 15 mg in people with type 2 diabetes, with doses above 5 mg reached by stepping up11.

In animal studies

Rats: 0.15, 0.50 and 1.5 mg/kg injected under the skin twice weekly for 2 years; thyroid C-cell adenomas and carcinomas combined rose at all doses1. rasH2 transgenic mice: 1, 3 and 10 mg/kg twice weekly for 6 months; it did not cause tumors1. Rat fertility studies: 0.5, 1.5 and 3 mg/kg twice weekly; no effect on mating, fertility or conception, but female rats had fewer implantation sites and viable embryos at all doses, which the label attributes to lower food intake and body weight1. These are animal safety-study doses, not human doses.

What users report Anecdotal · not validated · not a recommendation

A 2026 journal commentary says “microdosing” of single- and dual-receptor GLP-1 drugs (tirzepatide is a dual agonist) is typically defined as 25% to 50% of the manufacturer’s recommended starting dose, or longer intervals between doses. It says the practice spread through patient communities, telehealth weight-loss programs and clinician anecdotes, and that high-quality evidence is essentially absent21.

Half-life
About 5 to 6 days1Adults with overweight or obesity, including those with sleep apnea, after subcutaneous injection (Zepbound label, clinical pharmacology section); the same label’s overdose section rounds it to about 5 days. Tirzepatide is 99% bound to albumin.
Routes
  • Subcutaneous injection, once weekly (the only approved route and the route used in all trials cited here)

Every dose studied for Tirzepatide, with sources →

Quality and the gray market

What testing finds

Finnrick, a US testing service, had published 2,744 tirzepatide tests covering 262 vendors through 25 September 2026. Of the latest 200 shown on 30 September 2026, 137 passed, 59 failed and 4 were incomplete, a 30.1% fail rate among completed tests4. Its users are self-selected, so its results are not a random sample of the market438. Its default pass mark is purity of at least 99.5% and content within 35% of the label439. Compounded products raise their own concerns. Lilly scientists who tested compounded tirzepatide-plus-B12 products obtained in the US reported a widespread, previously unknown impurity that forms when tirzepatide reacts with some forms of vitamin B12; its clinical effects are unknown40. FDA says it has found fraudulent compounded tirzepatide whose labels name pharmacies that do not exist or did not make the product3. Counterfeits of the brand also circulate: two pens detained in Ireland in 2025 contained insulin instead of tirzepatide41, and the MHRA reported falsified Mounjaro 15 mg pens in 202630.

How it is sold

Outside normal prescriptions, tirzepatide is sold in three main forms. Online sellers offer “research use only” vials: FDA warning letters of 24 August 2026 quote product names such as “GLP-2 T (Tirzepatide)” and “GLP-2 Tirz Peptide”4243, and a 2025 letter quoted a listing titled “5mg Tirzepatide (Mounjaro) 5mg”44. FDA says such products are sold for human use with dosing instructions3. On 23 July 2026 prosecutors announced a 21-month sentence for a Michigan man who sold semaglutide and tirzepatide through websites that called them “for research purposes only”45. Compounded versions are still sold through clinics and med spas: a secret-shopper study in West Virginia and Oklahoma (August to October 2025) found 75 clinics and med spas offering compounded GLP-1 drugs after the shortages ended, 42 of them combined with B vitamins, and 4 of 21 supplying facilities were not licensed for sterile compounding46. Counterfeit brand-name pens are the third form3041. Prices on Finnrick’s leaderboard for its eight top-rated tirzepatide vendors ran from $0.34 to $0.64 per mg (tests through 25 September 2026; how prices were collected is not stated)4. Demand is large: tirzepatide made up 23.4% of the 21,253 test requests Finnrick received from May 2025 to May 2026, second only to retatrutide (our count from its chart data)38, and the r/tirzepatidecompound forum had 125,862 weekly visitors and 15,104 weekly contributions on 30 September 202647.

Side effects and risks

  • Gut side effects are the most common: nausea, diarrhea, vomiting and constipation, mostly mild to moderate and mostly while the dose is being raised12. Severe gut reactions have been reported, and the label does not recommend it for people with severe gastroparesis1.
  • Boxed warning: tirzepatide caused thyroid C-cell tumors in rats, and whether it does so in people is unknown. People with a personal or family history of medullary thyroid cancer or MEN 2 must not use it1.
  • Other label warnings: acute pancreatitis, gallbladder disease, kidney injury from dehydration, serious allergic reactions, low blood sugar (more likely with insulin or sulfonylureas), temporary worsening of diabetic eye disease (retinopathy) in type 2 diabetes, and inhaling stomach contents during anesthesia or deep sedation1.
  • It can make birth-control pills less effective. The label advises switching to a non-oral method, or adding a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase1.
  • Weight tends to come back after stopping: in SURMOUNT-4, people switched to placebo gained 14.0% in weight over 52 weeks9.
  • FDA has adverse-event reports that may be linked to compounded tirzepatide used above label doses: larger doses, more frequent doses or faster increases3.
  • Compounded and gray-market products carry risks the trials did not test: wrong strength, impurities, fake labels and counterfeits344041. A study of FDA’s adverse-event database (2018 to 2024) linked compounded GLP-1 drugs, including tirzepatide, to higher odds of hospitalization and of contamination reports than non-compounded products; such data show associations, not causes48.
  • Legal risk: selling research-labeled tirzepatide for human use is illegal in the US, and sellers have been prosecuted345. Athletes: it is not prohibited, but WADA monitors it34.

Documented harms

  • 10 Oct 2025Ireland’s HPRA said lab tests confirmed that two counterfeit tirzepatide pens, detained by Ireland’s customs service, contained insulin instead of tirzepatide41. Injecting them could cause severe low blood sugar (hypoglycemia)41. The shipment was sourced online and came from outside Europe; HPRA had no reports of harm and no evidence that these pens had reached users41.
  • 24 Feb 2026The UK MHRA reported five falsified Mounjaro KwikPen 15 mg pens (batch D873576) supplied through one online pharmacy30. All had a faulty mechanism, and in all but one the dose knob came off during use30. The MHRA said they likely held tirzepatide but were not safe to use, and it had no reports of harm that needed treatment30.
  • 31 May 2026FDA had received more than 730 adverse-event reports associated with compounded tirzepatide as of 31 May 2026. It says such events are likely underreported and that a report does not always mean the drug caused the event. It also described an injection-site reaction to a product labeled as compounded tirzepatide from a pharmacy that did not make it3.
  • Jun 2026Case report: a 66-year-old woman developed persistent nodules at facial filler and botulinum toxin injection sites after starting compounded tirzepatide. New nodules stopped forming after she stopped it, and two small nodules formed again after she restarted and raised the dose. The product’s ingredients were unknown, the nodules were not biopsied, and the authors could not draw causal conclusions49.

Questions people ask

Is tirzepatide FDA approved?

Yes. FDA approved it as Mounjaro for type 2 diabetes in 2022 and as Zepbound for weight management in 2023 and for obstructive sleep apnea with obesity in 202456. On 27 August 2026 Mounjaro also gained approval to lower the risk of heart attack, stroke and cardiovascular death in adults with type 2 diabetes at high risk7.

How much weight do people lose on tirzepatide?

In SURMOUNT-1, average losses at 72 weeks were 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, versus 3.1% on placebo2. Weight tends to return after stopping9.

Tirzepatide vs semaglutide: what’s the difference?

Semaglutide acts on the GLP-1 receptor; tirzepatide acts on both the GLP-1 and GIP receptors150. In SURMOUNT-5, which compared weekly injections of each, weight fell 20.2% with tirzepatide versus 13.7% with semaglutide at 72 weeks8.

What is the usual tirzepatide dose?

On the Zepbound label, treatment starts at 2.5 mg once weekly for 4 weeks and rises in 2.5 mg steps, at least 4 weeks apart, to a maintenance dose of 5, 10 or 15 mg; the maximum is 15 mg weekly1. The 2.5 mg starting dose is not a Zepbound maintenance dose1.

Is tirzepatide banned in sport?

No. It is not on WADA’s 2026 or 2027 Prohibited List, and WADA said the status of GLP-1 drugs will stay unchanged for 2027333536. WADA monitors it in and out of competition3437.

What is still unknown

  • Whether tirzepatide reduces deaths and heart events in people with obesity but without diabetes (SURMOUNT-MMO; primary completion estimated October 2027).
  • Whether the benefit in fatty liver disease (MASH) holds up in Phase 3 trials.
  • Effects beyond about 4 years of use.
  • What research-labeled and compounded products actually contain, and the clinical effect of the B12-reaction impurity reported by Lilly scientists.
  • How often gray-market users are harmed: pharmacies that are not outsourcing facilities need not report adverse events to FDA, so its counts are likely low.
  • Whether “microdosing” helps or harms; we found no controlled trials.
  • How Finnrick derives its price-per-mg figures.
  • Vendor code names such as T-30, G2-TRZ and GLP-2 are our inference from vendor listings.
  • UK marketing authorization details for Mounjaro were not checked.

Sources

  1. 1ZEPBOUND (tirzepatide) injection, for subcutaneous use: prescribing information Eli Lilly and Company via DailyMed (U.S. National Library of Medicine), 28 Aug 2026. dailymed.nlm.nih.gov
  2. 2Tirzepatide Once Weekly for the Treatment of Obesity New England Journal of Medicine, 21 Jul 2022. pubmed.ncbi.nlm.nih.gov
  3. 3FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss U.S. Food and Drug Administration, 1 Oct 2026. fda.gov
  4. 4Tirzepatide: vendor test results Finnrick, 29 Sep 2026. finnrick.com
  5. 5Drugs@FDA via openFDA: approval history for NDA 215866 (Mounjaro) and NDA 217806 (Zepbound) U.S. Food and Drug Administration (openFDA), accessed 1 Oct 2026. api.fda.gov · data query
  6. 6FDA approves Zepbound (tirzepatide) as the first and only prescription medicine for moderate-to-severe obstructive sleep apnea in adults with obesity Eli Lilly and Company (PR Newswire), 20 Dec 2024. prnewswire.com
  7. 7Supplement approval letter, NDA 215866/S-044 and S-045 (Mounjaro) U.S. Food and Drug Administration, 27 Aug 2026. accessdata.fda.gov
  8. 8Tirzepatide as Compared with Semaglutide for the Treatment of Obesity New England Journal of Medicine, 3 Jul 2025. pubmed.ncbi.nlm.nih.gov
  9. 9Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial JAMA, 2 Jan 2024. pubmed.ncbi.nlm.nih.gov
  10. 10FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize U.S. Food and Drug Administration, 1 Apr 2026. fda.gov
  11. 11LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: From discovery to clinical proof of concept Molecular Metabolism, Dec 2018. pubmed.ncbi.nlm.nih.gov
  12. 12Mounjaro (tirzepatide): EPAR medicine overview European Medicines Agency, 18 Aug 2026. ema.europa.eu
  13. 13PubChem Compound Summary: CID 166567236 (synonyms include tirzepatide, Mounjaro and Zepbound) PubChem, U.S. National Library of Medicine, accessed 1 Oct 2026. pubchem.ncbi.nlm.nih.gov
  14. 14KEGG DRUG: Tirzepatide (D11360) KEGG, Kanehisa Laboratories, accessed 1 Oct 2026. kegg.jp
  15. 15Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes New England Journal of Medicine, 18 Dec 2025. pubmed.ncbi.nlm.nih.gov
  16. 16Tirzepatide for Obesity Treatment and Diabetes Prevention New England Journal of Medicine, 6 Mar 2025. pubmed.ncbi.nlm.nih.gov
  17. 17Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity New England Journal of Medicine, 3 Oct 2024. pubmed.ncbi.nlm.nih.gov
  18. 18Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity New England Journal of Medicine, 30 Jan 2025. pubmed.ncbi.nlm.nih.gov
  19. 19Tirzepatide for Metabolic Dysfunction-Associated Steatohepatitis with Liver Fibrosis New England Journal of Medicine, 25 Jul 2024. pubmed.ncbi.nlm.nih.gov
  20. 20A Study of Tirzepatide (LY3298176) on the Reduction on Morbidity and Mortality in Adults With Obesity (SURMOUNT-MMO), NCT05556512 ClinicalTrials.gov, 7 Oct 2026. clinicaltrials.gov
  21. 21Considerations and challenges in microdosing of GLP-1-based receptor agonists Expert Opinion on Pharmacotherapy, 5 Oct 2026. pubmed.ncbi.nlm.nih.gov
  22. 22FDA approves Lilly’s Mounjaro (tirzepatide) to reduce cardiovascular risk in adults with type 2 diabetes Eli Lilly and Company (PR Newswire), 28 Aug 2026. prnewswire.com
  23. 23MOUNJARO (tirzepatide) injection, for subcutaneous use: prescribing information Eli Lilly and Company via DailyMed (U.S. National Library of Medicine), 27 Aug 2026. dailymed.nlm.nih.gov
  24. 24Corrected supplement approval letter, NDA 217806/S-041 (Zepbound) U.S. Food and Drug Administration, 2 Sep 2026. accessdata.fda.gov
  25. 25Outsourcing Facilities Ass’n v. FDA, No. 25-10600 (5th Cir.) (unpublished, per curiam) US Court of Appeals for the Fifth Circuit, 27 Aug 2026. ca5.uscourts.gov
  26. 26List of Bulk Drug Substances for Which There Is a Clinical Need Under Section 503B of the Federal Food, Drug, and Cosmetic Act Federal Register (U.S. Food and Drug Administration), 1 May 2026. federalregister.gov
  27. 27Warning letter to Empower Clinic Services, LLC dba Empower Pharmacy (MARCS-CMS 738238) U.S. Food and Drug Administration, 18 Sep 2026. fda.gov
  28. 28Warning about sharp rise in illegal medicines sold in the EU European Medicines Agency, 3 Sep 2025. ema.europa.eu
  29. 29MHRA smashes major illicit weight loss medicine production facility in record seizure Medicines and Healthcare products Regulatory Agency (GOV.UK), 24 Oct 2025. gov.uk
  30. 30Falsified Mounjaro KwikPen 15mg pre-filled pens Medicines and Healthcare products Regulatory Agency, Drug Safety Update (GOV.UK), 24 Feb 2026. gov.uk
  31. 31Prescription Drug List: Human Use Health Canada (Drug and Health Product Register), accessed 30 Sep 2026. hpr-rps.hres.ca
  32. 32Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026 (F2026L01327) Federal Register of Legislation, Australian Government, 28 Sep 2026. legislation.gov.au
  33. 33World Anti-Doping Code International Standard: Prohibited List 2026 World Anti-Doping Agency, 24 Sep 2025. wada-ama.org
  34. 34The 2026 Monitoring Program World Anti-Doping Agency, Sep 2025. wada-ama.org
  35. 35WADA publishes 2027 Prohibited List World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  36. 36World Anti-Doping Code International Standard: Prohibited List 2027 World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  37. 37The 2027 Monitoring Program World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  38. 38We’d Rather Buy the Future Than Wait For It Finnrick, 10 Jun 2026. finnrick.com
  39. 39Methodology Finnrick, accessed 30 Sep 2026. finnrick.com
  40. 40A novel, widespread impurity in mass-compounded tirzepatide/B12 products: potential patient safety implications Expert Opinion on Drug Safety, May 2026. pubmed.ncbi.nlm.nih.gov
  41. 41HPRA health warning after detention of counterfeit tirzepatide pens containing insulin Health Products Regulatory Authority (Ireland), 10 Oct 2025. hpra.ie
  42. 42Warning letter to Peptide Partners LLC (MARCS-CMS 735063) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  43. 43Warning letter to NuScience Peptides LLC (MARCS-CMS 733652) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  44. 44Warning letter to USApeptide.com (MARCS-CMS 696885) U.S. Food and Drug Administration, 26 Feb 2025. fda.gov
  45. 45Gobles Man Sentenced for Selling Chinese Drugs Without FDA Approval U.S. Attorney’s Office, Western District of Michigan, 23 Jul 2026. justice.gov
  46. 46Postshortage Compounded GLP-1 RA Market in 2 States With Potentially High Demand JAMA Health Forum, 2 Jul 2026. pubmed.ncbi.nlm.nih.gov
  47. 47r/tirzepatidecompound (subreddit page, weekly visitor count) Reddit, accessed 30 Sep 2026. embed.reddit.com
  48. 48Safety analysis of compounded GLP-1 receptor agonists: a pharmacovigilance study using the FDA adverse event reporting system Expert Opinion on Drug Safety, Mar 2026. pubmed.ncbi.nlm.nih.gov
  49. 49Facial nodules following filler injections after initiating compounded tirzepatide use JAAD Case Reports, Jun 2026. pubmed.ncbi.nlm.nih.gov
  50. 50Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes New England Journal of Medicine, 5 Aug 2021. pubmed.ncbi.nlm.nih.gov
  51. 51Outcome of assessment on use of Mounjaro in treatment of obstructive sleep apnoea (EMA/576853/2024) European Medicines Agency, 13 Dec 2024. ema.europa.eu
  52. 52Outcome of assessment on use of Mounjaro in treatment of heart failure with preserved ejection fraction in adults with obesity (EMA/18704/2026) European Medicines Agency, 30 Jan 2026. ema.europa.eu
  53. 53Outcome of assessment on use of Mounjaro to reduce the risk of serious events affecting the heart and blood circulation (EMA/140483/2026) European Medicines Agency, 26 Jun 2026. ema.europa.eu
  54. 54More Than $126K in Notices for Illegal Prescription Drug Imports and Ads Mirage News (republished Therapeutic Goods Administration release), 6 Oct 2026. miragenews.com
  55. 55GLP-1 Medication & Behavioral Health Programs on Weight & Metabolic Outcomes: FLOURISH and THRIVE Prospective Cohort Study (NCT07588984) ClinicalTrials.gov, 15 May 2026. clinicaltrials.gov

Not medical advice. This page reports what studies and regulators say; it does not recommend using any product. How we grade evidence · Report an error.