Dual GIP/GLP-1 Receptor Agonism, Glycaemic Control & Weight Reduction
Tirzepatide (sold by Purgo Labs as "GLP-2 T") — Dual GIP/GLP-1 Receptor Agonist
Last reviewed: September 2026
Tirzepatide is the molecule in Mounjaro and Zepbound. Purgo Labs sells it under the name "GLP-2 T" — the T is the only clue — so if you were expecting a GLP-2 gut peptide, this is not that. It is a once-weekly incretin drug in its approved form and a lyophilised research powder in the form sold here.
It switches on two gut-hormone receptors at once. The GLP-1 side makes the pancreas release insulin when glucose is high, damps glucagon, slows the stomach and reduces appetite. The GIP side adds a second insulin signal and appears to help with appetite and with tolerability. A fatty-acid tail keeps the molecule bound to albumin so a single dose lasts around five days.
It produced the largest weight loss of any approved medicine at the time of its approval — around 21% of body weight at the top dose over 72 weeks in SURMOUNT-1 — and beat semaglutide head-to-head in type 2 diabetes. That is why 'GLP-2 T' is one of the most searched products on vendor sites, and why identity checking on research lots matters.
Strong human evidence for the approved drug; none for any research vial. Research-grade tirzepatide is for laboratory use only. Check the lot certificate for identity and measured net content before drawing any conclusion from it.
Identity note (12 September 2026): the product Purgo Labs lists as "GLP-2 T" is tirzepatide. Purgo's own listing describes it as an "acylated 39-amino-acid dual-pathway receptor agonist", its certificates carry the lot prefix PL-TR, and it is sold in 10mg and 20mg vials — none of which fits teduglutide, the GLP-2 analog an earlier version of this page described. This profile has been corrected to tirzepatide.
Tirzepatide is a 39-amino-acid synthetic peptide built on the GIP (glucose-dependent insulinotropic polypeptide) backbone and engineered to activate both the GIP receptor and the GLP-1 receptor. A C20 fatty diacid attached through a linker binds albumin and extends the half-life to about five days, which is what allows once-weekly dosing of the approved products.
It is FDA-approved as Mounjaro® (type 2 diabetes, 2022) and Zepbound® (chronic weight management, 2023; obstructive sleep apnoea in obesity, 2024). Research-grade tirzepatide sold as a lyophilised powder is not the approved product and is supplied for laboratory use only.
Tirzepatide is a 39-residue linear peptide based on native GIP(1-42) with substitutions taken from GLP-1 and exendin-4 sequence, α-aminoisobutyric acid (Aib) at positions 2 and 13 for protease resistance, and a C20 fatty diacid attached at Lys20 through a γ-glutamate and two 8-amino-3,6-dioxaoctanoic acid (OEG) units. Molecular weight 4,813.5 Da (C225H348N48O68). The lipid side chain is the albumin-binding element responsible for its roughly five-day half-life.
Tirzepatide activates both the GIP and GLP-1 receptors — combining glucose-dependent insulin release, appetite suppression and slowed gastric emptying with a second incretin signal — and its fatty-acid side chain keeps it in circulation for about five days.
Tirzepatide is an agonist at two incretin receptors. At the GLP-1 receptor it behaves like other GLP-1 agonists — glucose-dependent stimulation of insulin secretion, suppression of glucagon, slowed gastric emptying and reduced appetite through hypothalamic and hindbrain GLP-1 receptors. At the GIP receptor it adds a second incretin signal: GIP potentiates insulin secretion, acts on adipose tissue, and in the brain appears to contribute to reduced food intake and to blunting of GLP-1-related nausea.
Tirzepatide has an imbalanced profile — its affinity for the GIP receptor is comparable to native GIP while its GLP-1 receptor potency is roughly five-fold lower than native GLP-1, and it shows biased signalling at GLP-1R (favouring cAMP generation over β-arrestin recruitment, which reduces receptor internalisation). Whether the GIP component explains the larger weight loss seen versus semaglutide is still debated; the head-to-head trial evidence is in the references below.
Glucose-dependent potentiation of insulin secretion, glucagon suppression, slowed gastric emptying and central appetite reduction.
Second incretin input on β-cells and adipose tissue; central GIPR activity is implicated in food-intake reduction and in reducing GLP-1-related nausea.
Favours cAMP over β-arrestin recruitment, reducing receptor internalisation and prolonging signalling.
The C20 fatty-diacid side chain binds serum albumin, giving a half-life of about five days and once-weekly dosing in the approved products.
Each outcome rated by the highest level of evidence available. Tiers follow our 5-tier methodology.
Study counts reflect peer-reviewed publications in the evidence database below. "Theoretical" outcomes have mechanistic rationale only. Learn about our evidence tiers →
Tirzepatide — half-life, bioavailability, onset, and duration data
| Parameter | Value | Source |
|---|---|---|
| Half-Life (t½) | ~5 days (120 hours) Range: 96–144 hours Enables once-weekly dosing | Prescribing Information |
| Time to Peak (Tmax) | 8–72 hours Median ~24 hours after subcutaneous injection | Prescribing Information |
| Bioavailability (F) | ~80% | Prescribing Information |
| Protein Binding | >99% Albumin-bound via fatty acid chain | Prescribing Information |
| Volume of Distribution (Vd) | ~10.3 L | Prescribing Information |
| Elimination | Proteolytic degradation; renal excretion of metabolites | Prescribing Information |
| Onset of Action | 1–2 weeks Meaningful glucose reduction; weight loss over 4–16 weeks | — |
| Duration of Action | 7 days per dose | — |
Dual GIP/GLP-1 agonist. Shorter half-life than semaglutide but still enables once-weekly dosing. Steady state at 4 weeks.
References:
• Mounjaro US Prescribing Information 2023
• Zepbound US Prescribing Information 2023
Peer-reviewed literature supporting the research profile of Tirzepatide
The following peer-reviewed studies form the primary evidence base for Tirzepatide's research profile. All references are sourced from PubMed, NCBI, and peer-reviewed scientific journals. Published research is available through PubMed, NCBI, and peer-reviewed biomedical journals.
Frias JP, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. New England Journal of Medicine. 2021.PMID: 34170647
Tirzepatide (GLP-2-T) demonstrated superior HbA1c reduction and weight loss versus semaglutide in SURPASS-2 trial.
Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine. 2022.PMID: 35658024
SURMOUNT-1: tirzepatide achieved up to 22.5% body weight reduction — among the highest reported for any pharmacological intervention.
Nauck MA, D'Alessio DA. Tirzepatide, a dual GIP/GLP-1 receptor co-agonist for the treatment of type 2 diabetes with unmatched effectiveness. Cardiovascular Diabetology. 2022.PMID: 36050763
Mechanistic review of dual GIP/GLP-1 receptor co-agonism explaining tirzepatide's superior efficacy.
Metabolic Research
Purgo Labs list price, read 12 Sep 2026 · per-lot COA on the vendor page
10mg $49.99 → $39.99 with code HEALTH (20% off; price read 1 Nov 2026)
Fast FedEx shipping · Discreet packaging
View full legal status guide →
6 documented interactions for Tirzepatide
Both are GLP-1 receptor agonists. Combining significantly increases risk of severe hypoglycemia, pancreatitis, and GI adverse effects. Contraindicated.
Both affect glucose metabolism. Monitor blood glucose if combining.
Both affect fat metabolism. Monitor for excessive fat loss when combining.
BPC-157 may support GI health during GLP-1/GIP therapy. No known negative interaction.
Interaction data is based on published research, known pharmacological mechanisms, and clinical practitioner experience. Evidence tiers: Clinical = human data; Emerging = preclinical/case reports; Theoretical = mechanism-based inference. Always consult a qualified healthcare provider before combining compounds.
Source Tirzepatide at Purgo Labs
10mg $49.99 list · $39.99 with code HEALTH · lab-verifiable COA per lot
Since the 2025–26 enforcement wave almost no vendor lists tirzepatide by name. These are the 41 house codes we have read on vendor pages. 26 of them come with a stated identity (a CAS number, a lab lot prefix on the vendor's certificate page, or the vendor's own FAQ); the rest are codes only, and we keep those out of the price table.
Full decoder: every GLP-1, tirzepatide and retatrutide vendor code, with the evidence behind each · green = identity stated, amber = code only
Approved drug (Mounjaro / Zepbound) with large randomised trials — figures are from those trials
Tirzepatide's adverse-effect profile comes from the SURMOUNT and SURPASS programmes and is dominated by dose-related gastrointestinal effects, similar in kind to semaglutide. Research-grade tirzepatide is not the approved product and carries the additional, unmeasured risk of unverified identity and dose.
Research-use information only. Research-grade Tirzepatide is not an approved medicine; where trial or label figures appear below they belong to the pharmaceutical product studied, not to any research vial. This section does not give dosing or medical advice.
Every rate carries its source. Where no source exists, no rate is printed.
| Effect | Rate (sourced) | Detail | Source |
|---|---|---|---|
| Nausea | 24.6–33.3% (5–15 mg) vs 9.5% placebo | Mostly during escalation. | SURMOUNT-1, Jastreboff et al. 2022 |
| Diarrhoea | 18.7–23.0% vs 7.3% | — | SURMOUNT-1 |
| Vomiting | 8.3–12.2% vs 1.7% | — | SURMOUNT-1 |
| Constipation | 11.7–17.1% vs 5.8% | — | SURMOUNT-1 |
| Discontinuation for adverse events | 4.3–7.1% vs 2.6% | — | SURMOUNT-1 |
Regulatory status: FDA-approved as Mounjaro (2022) and Zepbound (2023). Research-grade tirzepatide is not approved for any use.
Everything above describes Tirzepatide the molecule. The risk specific to a research vial is different: it may not contain Tirzepatide at the labelled amount, and it may contain what the synthesis left behind. Identity (mass spectrometry), purity (HPLC), measured net content and an endotoxin result are the four lines on a certificate that bear on adverse effects, and only a certificate you can check at the laboratory tells you any of them. This is what we have verified for Tirzepatide so far.
29 of the 105 vendors on our scoreboard list Tirzepatide with a price we read on the product page (5 Sep 2026–1 Nov 2026). Of those, 28 name their testing laboratory, 23 publish certificates that resolve on the lab's own site, and 28 publish measured milligrams against the label. The full ranking, with every dated price, is on Best Tirzepatide Vendors.
| Vendor | Rubric | Lab named | Price read |
|---|---|---|---|
| Idun Peptides | 10/10 | Kovera Labs (named in certificate captions only) | $24.99 · 10mg · 5 Sep 2026 |
| MyPurePeptidepartner | 10/10 | Janoshik Analytical | $47.00 · 5mg · 9 Oct 2026 |
| Panda Peptides | 10/10 | Janoshik Analytical · ILS Labs (per batch) | $36.95 · 10mg · 25 Oct 2026 |
| Peptide Giantspartner | 10/10 | Janoshik Analytical · Vanguard Laboratory | $39.99 · 10mg · 1 Nov 2026 |
| Premier Bio Labs | 10/10 | ILS Laboratories + Freedom Diagnostics | $34.99 · 10mg · 1 Nov 2026 |
Top 5 by rubric score; 24 more on the ranking page.
2 certificates for Tirzepatide in the COA library: 0 checkable on the laboratory's own site, 1 stating measured mass against the label, 2 carrying a flag.
Head-to-head tolerability has not been the primary endpoint of a trial; in separate trials the GI rates look broadly similar in kind, with tirzepatide's nausea rate somewhat lower at comparable efficacy. Individual response varies more than the averages.
Side-effect section last reviewed 2026-09-12. Moved from the standalone side-effects page on 10 October 2026; text unchanged.
Tirzepatide is FDA-approved as Mounjaro (type 2 diabetes) and Zepbound (weight management). Research-grade tirzepatide is available as a research chemical. It is not a controlled substance but requires a prescription for clinical human use.
| Jurisdiction | Status as stated |
|---|---|
| United States | FDA-approved as Mounjaro and Zepbound. Not a controlled substance. Research-grade tirzepatide is available as a research chemical. The FDA has issued guidance on compounded tirzepatide. |
| Canada | Approved by Health Canada as Mounjaro. Available by prescription. |
| United Kingdom | Licensed by the MHRA as Mounjaro. Available by prescription. |
| Australia | Approved by the TGA as Mounjaro. Available by prescription. |
| European Union | Approved by the EMA as Mounjaro. Available by prescription across EU member states. |
Statements above are as our legal-status page for Tirzepatide stated them in 2025; they were moved here on 10 October 2026 and were not re-verified in the move. Regulations change. This is general information, not legal advice; check the current position with your own jurisdiction's regulator before relying on it.
No. Tirzepatide is not listed as a controlled substance under the DEA Controlled Substances Act. It is a prescription drug but not scheduled.
Yes. Research-grade tirzepatide is available as a research chemical for legitimate laboratory research purposes. It is not the same as prescription Mounjaro or Zepbound.
The FDA has issued guidance on compounded tirzepatide. During drug shortages, compounding was permitted. As the shortage resolves, the FDA has moved to restrict compounding.
Tirzepatide is the active ingredient in Mounjaro and Zepbound. Research-grade tirzepatide has the same molecular structure but is produced for laboratory research purposes only.
Clinical trials show tirzepatide produces greater average weight loss (approximately 22% body weight) compared to semaglutide (approximately 15% body weight). Both are FDA-approved for weight management.
Tirzepatide has large Phase 3 human RCT support (SURPASS in type 2 diabetes, SURMOUNT in obesity) including a head-to-head trial against semaglutide. Claims about the approved drug can be stated with confidence when cited; none of it validates a research-grade vial.
Purgo Labs offers Tirzepatide with ≥99% purity, third-party certificates of analysis, and fast FedEx shipping. This is an affiliate link — we may earn a commission at no cost to you.
