Mounjaro research centres on one molecule: tirzepatide — a 39-amino acid synthetic peptide engineered to simultaneously activate both the GIP (glucose-dependent insulinotropic polypeptide) receptor and the GLP-1 (glucagon-like peptide-1) receptor with balanced affinity, creating a dual incretin signalling profile that no single-receptor agonist can replicate. Across the SURPASS and SURMOUNT clinical trial programmes, tirzepatide produced metabolic effect sizes that substantially exceeded those of GLP-1 mono-agonists such as semaglutide — a finding that has fundamentally reshaped the research landscape for incretin-based metabolic investigation.
This article covers the molecular architecture of tirzepatide, the biology of both receptor systems it engages, the clinical trial parameters documented across the SURPASS and SURMOUNT programmes, and how dual GIP/GLP-1 agonism compares to the emerging triple agonist approach seen in retatrutide. All content reflects published peer-reviewed literature only.
Compliance notice: Tirzepatide is a prescription-only medication (POM) in the United Kingdom and many other jurisdictions. Pure Grade Labs supplies tirzepatide strictly as a research chemical for laboratory use only. Not for human consumption. This article discusses published clinical trial data and receptor biology — it does not constitute medical advice.
Key Takeaways
- Tirzepatide (Mounjaro) is a single 39-amino acid molecule engineered to activate both GIP and GLP-1 receptors with balanced affinity — the defining feature that distinguishes it from GLP-1 mono-agonists.
- SURMOUNT-1 enrolled 2,539 participants over 72 weeks; the 15mg dose group demonstrated up to 22.5% body weight reduction in the highest-responding participants, with a mean reduction of 20.9%, versus 2.4% (mean) in the placebo group.
- SURPASS-2 (Frias et al., NEJM 2021) demonstrated tirzepatide's superior metabolic outcomes compared to semaglutide 1mg across all three dose groups in a head-to-head randomised controlled trial.
- GIP receptor activation adds a distinct adipose tissue signalling pathway — GIPR is expressed in adipocytes and has been shown to influence lipid metabolism independently of GLP-1R — which may amplify the overall metabolic effect observed in dual agonism research models.
- Tirzepatide is a prescription-only medication in many jurisdictions. Pure Grade Labs supplies it as a research chemical for laboratory use only. Not for human consumption.
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Browse the Research Range →What Is Tirzepatide? Molecular Architecture of a Twincretin
Tirzepatide is a synthetic peptide of 39 amino acids developed by Eli Lilly. Its molecular weight is approximately 4,813 Da. The compound belongs to a newly defined pharmacological class called "twincretins" — single molecules engineered to engage two separate incretin hormone receptors with co-agonist activity. This is distinct from co-administration of two separate receptor-specific molecules, because a single molecular entity entering the receptor microenvironment produces a different downstream signalling geometry than two separate ligands binding independently.
The sequence of tirzepatide is based on the native GIP sequence, modified to confer GLP-1R activity. A C20 fatty diacid chain is attached to the peptide backbone via a gamma-glutamic acid linker at lysine-26, enabling reversible albumin binding in plasma. This modification is structurally analogous — though not identical — to the fatty acid conjugation used in semaglutide, and serves the same pharmacokinetic purpose: protecting the peptide from rapid enzymatic degradation and extending plasma half-life to approximately five days.
Critically, the GIP/GLP-1 receptor affinities in tirzepatide are not equal — the molecule was engineered with approximately equivalent affinity at GIPR (human EC50 ~22 pM) and slightly lower intrinsic potency at GLP-1R compared to native GLP-1. This balanced affinity profile is intentional: it avoids the ceiling-level GLP-1R saturation that can amplify the nausea and vomiting side effect profile observed with high-dose GLP-1 mono-agonists, while enabling the GIP receptor component to contribute meaningfully to the overall pharmacological signal.
GIP Receptor Biology: The Historically Overlooked Incretin
GIP (glucose-dependent insulinotropic polypeptide) is a 42-amino acid peptide hormone secreted by K-cells in the proximal small intestine (duodenum and proximal jejunum) following ingestion of glucose and fat. It is one of the two primary incretin hormones — alongside GLP-1 — responsible for the incretin effect: the amplification of glucose-stimulated insulin secretion that occurs when nutrients arrive via the gastrointestinal tract rather than intravenously.
The GIP receptor (GIPR) is a Gs-protein coupled receptor (GPCR). Following GIP binding, Gs activation stimulates adenylyl cyclase, elevating intracellular cyclic AMP (cAMP) in pancreatic beta cells. This triggers protein kinase A (PKA) activation and downstream insulin granule exocytosis — a glucose-dependent mechanism, meaning GIPR signalling amplifies insulin release only when blood glucose is already elevated, not independently. GIPR expression is documented in pancreatic beta cells, adipocytes, osteoblasts, and regions of the central nervous system including the hypothalamus and hippocampus.
Prior to tirzepatide research, GIP was widely regarded as pharmacologically irrelevant in obesity and metabolic disease — partly because GIP responses appeared blunted in obese individuals (a phenomenon termed "GIP resistance"), and partly because GLP-1 agonism had dominated incretin research since the early 2000s. A pivotal early observation was that exogenous GIP infusion in obese subjects produced weaker insulin responses than in lean controls, leading researchers to conclude that targeting GIPR would add little therapeutic value. Tirzepatide research fundamentally challenged this assumption.
Published preclinical data using GIPR knockout models and tirzepatide analogues demonstrated that restoring GIPR signalling — particularly in adipose tissue and the central nervous system — produced meaningful metabolic effects independent of the pancreatic insulin pathway. Research by Samms et al. (2021, Cell Metabolism, PMID: 34289344) proposed that the GIP resistance observed in obesity was reversible and that pharmacological GIPR agonism could overcome it, shifting the conceptual framework from "GIP is irrelevant in obesity" to "GIP's contribution has been studied with insufficient pharmacological tools."
GLP-1 Receptor Biology: The Satiety and Glycaemic Axis
GLP-1 (glucagon-like peptide-1) is secreted by L-cells in the distal small intestine and colon following nutrient ingestion, and to a lesser degree from neurons in the brainstem. The GLP-1 receptor (GLP-1R) is also a Gs-coupled GPCR. At pancreatic beta cells, GLP-1R activation parallels the GIPR mechanism — cAMP elevation, PKA activation, insulin granule exocytosis — but GLP-1R is expressed across a substantially broader tissue distribution than GIPR.
GLP-1R expression is confirmed in the hypothalamic arcuate nucleus and paraventricular nucleus (key satiety regulation centres), the nucleus of the solitary tract in the brainstem (vagal integration of gut signals), the nodose ganglion of the vagus nerve, gastric smooth muscle (where activation delays gastric emptying), and in cardiac and renal tissue. This broad distribution explains why GLP-1 receptor agonism produces effects beyond glycaemic control — reduced appetite, delayed gastric emptying, and the cardiovascular risk reduction demonstrated in GLP-1 outcomes trials such as LEADER (liraglutide) and SUSTAIN-6 (semaglutide).
In published satiety models, GLP-1R activation in the arcuate nucleus suppresses NPY/AgRP (orexigenic) neuron activity and activates POMC/CART (anorexigenic) neurons. The brainstem GLP-1R system integrates vagal signals from the gut that report nutrient presence — creating the neurological sensation of fullness. This is the primary mechanism through which GLP-1 receptor agonists reduce caloric intake in clinical trials. In tirzepatide, GLP-1R engagement at these CNS sites is layered on top of simultaneous GIPR activation in the hypothalamus — producing a satiety signal that both receptor systems contribute to independently.
Dual Agonism vs Single Agonism: More Than Additive
The distinction between additive and synergistic receptor signalling is critical to understanding why tirzepatide research produces larger effect sizes than GLP-1 mono-agonism at comparable GLP-1R engagement levels. If the effects were purely additive — GIP contribution simply stacking numerically on top of GLP-1 contribution — the weight loss signal in SURMOUNT-1 would be predictable from GLP-1 mono-agonist data plus a modest increment. Published evidence suggests the reality is more complex.
In adipose tissue, GIPR and GLP-1R activate overlapping but distinct intracellular cascades. GIPR activation in adipocytes promotes lipid storage under high-energy-availability conditions and enhanced lipid mobilisation under energy deficit conditions — a context-dependent role that differs mechanistically from GLP-1R's predominantly CNS-mediated satiety signalling. When both receptors are simultaneously engaged in the context of energy deficit (as in the caloric restriction observed across the tirzepatide trial populations), the combined adipose tissue signal appears to facilitate fat mass reduction at a greater rate than GLP-1 alone could produce.
In the hypothalamus, co-expression of GIPR and GLP-1R in overlapping neuronal populations means that a single molecule activating both receptors simultaneously may engage receptor heterodimer signalling dynamics not available to mono-agonists. While the precise molecular mechanism of this synergy in humans remains an active area of research, the clinical observation — that tirzepatide at 15mg produces ~20.9% weight loss vs ~17.4% for semaglutide 2.4mg at its highest studied dose — is consistent with a supra-additive satiety effect at the CNS level (Jastreboff et al., NEJM 2022; Wilding et al., NEJM 2021).
From a downstream pathway perspective: GLP-1R activation primarily drives cAMP/PKA and PI3K/Akt signalling. GIPR adds overlapping cAMP/PKA but also activates distinct beta-arrestin-mediated pathways in adipocytes that influence GLUT4 translocation and fatty acid oxidation enzyme expression — pathways that are not engaged by GLP-1R agonism alone. This mechanistic distinction helps explain the lean mass preservation signal in SURMOUNT-1 DEXA substudy data, where tirzepatide participants maintained a substantially higher lean mass proportion relative to total weight lost compared to historical GLP-1 mono-agonist benchmarks.
When the SURMOUNT-1 dataset was published in June 2022, one of the most discussed findings among metabolic researchers was not the headline weight loss figure — it was the body composition data. A secondary analysis showing disproportionate fat mass loss relative to lean mass caught immediate attention. Researchers working in incretin biology had long assumed that GIP receptor signalling would contribute modestly at best in obese populations, given the blunted GIP responses documented in obesity studies through the 2000s and 2010s. The SURMOUNT-1 data forced a reappraisal: GIP was not simply irrelevant in obesity — it had been studied with the wrong pharmacological tools. Tirzepatide was the first molecule capable of driving sufficient GIPR activation in an obese metabolic context to reveal what GIPR could actually contribute to fat mass regulation. The paradigm shift was immediate: GIP moved from footnote to frontline in metabolic research.
The SURPASS Programme: Type 2 Diabetes Trial Data
The SURPASS programme comprised eight phase 3 trials examining tirzepatide in populations with type 2 diabetes. Three trials are of particular research relevance.
SURPASS-1 (2021): Placebo-Controlled Efficacy
SURPASS-1 (Rosenstock et al., JAMA 2021, PMID: 34080030) enrolled 478 participants with type 2 diabetes on diet and exercise alone. The trial examined 5mg, 10mg, and 15mg weekly doses versus placebo over 40 weeks. At the primary endpoint, mean HbA1c reductions were −1.87%, −1.89%, and −2.07% for the three dose groups respectively, versus +0.04% for placebo (all p<0.001). Mean body weight changes were −7.0kg, −7.8kg, and −9.5kg versus −0.7kg for placebo. Notably, 31%, 40%, and 49% of participants in the 5mg, 10mg, and 15mg groups achieved HbA1c below 5.7% (normoglycaemia) — a research endpoint rarely achieved with any other pharmacological intervention in type 2 diabetes populations.
SURPASS-2 (2021): Head-to-Head vs Semaglutide
SURPASS-2 (Frias et al., NEJM 2021, PMID: 34170647) was the first randomised head-to-head comparison between tirzepatide and semaglutide 1mg weekly in 1,879 participants with type 2 diabetes over 40 weeks. Tirzepatide demonstrated statistically superior outcomes on both primary endpoints — HbA1c reduction and body weight loss — at all three dose levels.
HbA1c reductions were −2.01% (5mg), −2.24% (10mg), and −2.30% (15mg) for tirzepatide versus −1.86% for semaglutide 1mg. Body weight losses were −7.8kg (5mg), −10.3kg (10mg), and −12.4kg (15mg) versus −6.2kg for semaglutide. All tirzepatide doses achieved superiority on both endpoints (p<0.001). This trial provided the first head-to-head evidence that dual GIP/GLP-1 agonism was pharmacologically distinct from — and more potent than — optimised GLP-1 mono-agonism.
SURPASS-CVOT: Cardiovascular Outcomes Research
The SURPASS-CVOT trial (cardiovascular outcomes trial) enrolled over 13,000 participants with type 2 diabetes at high cardiovascular risk to assess whether the metabolic improvements produced by tirzepatide translate to reduced major adverse cardiovascular events (MACE) — a research question of major significance given the established cardiovascular benefit of GLP-1 mono-agonists. Results from this trial are contributing to the growing dataset on cardiovascular outcomes in incretin receptor biology and represent an important frontier in Mounjaro research beyond glycaemic control.
The SURMOUNT Programme: Obesity Research Data
SURMOUNT-1 (2022): The Landmark Publication
SURMOUNT-1 (Jastreboff et al., NEJM 2022, PMID: 35658024) enrolled 2,539 participants with obesity (BMI ≥30) or overweight (BMI ≥27) with at least one weight-related comorbidity, but without type 2 diabetes, across 19 countries. Participants were randomised to tirzepatide 5mg, 10mg, or 15mg weekly, or placebo, over 72 weeks. All groups received lifestyle intervention counselling.
At week 72, mean percentage weight reductions were 15.0% (5mg), 19.5% (10mg), and 20.9% (15mg) versus 3.1% for placebo — with maximum reductions in the 15mg group reaching 22.5% in the highest-responding quartile. All three active dose groups demonstrated statistical superiority versus placebo (p<0.001 for all). In the 15mg group, 57% of participants achieved ≥20% body weight reduction and 91% achieved ≥5% — benchmarks that had previously been regarded as exceptional outcomes for pharmaceutical intervention. The placebo group achieved ≥5% body weight reduction in only 35% of participants.
Secondary endpoints included improvements in waist circumference, blood pressure, lipid profiles, and insulin sensitivity markers, all of which showed statistically significant improvements in the active treatment groups. The body composition substudy (DEXA in a subset of 281 participants) found that fat mass accounted for approximately 90% of total mass lost in the tirzepatide groups — a lean mass preservation ratio that has been attributed in published discussion to GIPR-mediated signalling in skeletal muscle and adipose tissue.
SURMOUNT-2 and SURMOUNT-3
SURMOUNT-2 examined tirzepatide in participants with both obesity and type 2 diabetes over 72 weeks, producing mean weight reductions of 12.8% (10mg) and 14.7% (15mg) versus 3.2% placebo — confirming the efficacy signal in a diabetic obesity population where pharmacological weight loss is typically harder to achieve. SURMOUNT-3 examined tirzepatide following a 12-week intensive lifestyle intervention run-in, demonstrating that pharmacological intervention on top of behavioural intervention produced substantially larger sustained weight reduction than behavioural intervention alone.
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Browse the Full Range →Half-Life and Pharmacokinetic Profile
Tirzepatide has a published plasma half-life of approximately 5 days in humans, confirmed across multiple dose levels in phase 1 and phase 3 pharmacokinetic substudies. This is shorter than semaglutide's ~7-day half-life but substantially longer than native GIP (half-life ~5–7 minutes) or native GLP-1 (half-life ~2 minutes under DPP-IV degradation).
The extended half-life is produced by the C20 fatty diacid modification enabling reversible albumin binding. Approximately 99% of circulating tirzepatide is albumin-bound at any given time, protecting it from rapid DPP-IV degradation and renal clearance. The unbound fraction (~1%) is pharmacologically active and in dynamic equilibrium with the albumin-bound reservoir — which maintains sustained plasma concentrations across the dosing interval.
For research design purposes, the ~5-day half-life means that steady-state plasma concentrations (approximately 4–5 half-lives) are reached within approximately 3–4 weeks of weekly administration. Time-to-steady-state is an important parameter for research protocols studying metabolic endpoints, as pharmacological effects may not reach their maximum magnitude until steady-state concentrations are achieved. All published SURPASS and SURMOUNT trial efficacy data was measured at steady-state — which is why week 72 (SURMOUNT-1) and week 40 (SURPASS-1 and 2) endpoints reflect chronic exposure pharmacology, not acute effects.
In comparative pharmacokinetic terms, the shorter half-life of tirzepatide versus semaglutide means that plasma concentration fluctuation between weekly doses is slightly higher for tirzepatide — a pharmacokinetic distinction relevant to research designs studying acute versus chronic receptor activation dynamics.
UK Regulatory Status: Prescription-Only Medication
In the United Kingdom, tirzepatide is approved by the MHRA as a prescription-only medication (POM) under the brand name Mounjaro for the treatment of type 2 diabetes, and subsequently for chronic weight management. Its POM status means it is not legally available without a prescription from a qualified prescriber for any intended human use.
Pure Grade Labs supplies tirzepatide exclusively as a research chemical for laboratory use, under the framework applicable to research chemicals in the UK. This supply is entirely separate from the prescription medicine supply chain — Pure Grade Labs does not supply tirzepatide for human use, does not provide prescriptions or medical guidance, and does not position its products as substitutes for MHRA-approved medicines. All purchasers are responsible for compliance with applicable research and professional conduct regulations in their jurisdiction.
Dual Agonism to Triple Agonism: Tirzepatide vs Retatrutide
The logical research extension of dual GIP/GLP-1 agonism is triple agonism: adding glucagon receptor (GCGR) activity to the GIP/GLP-1 dual mechanism. Retatrutide (LY3437943) is Eli Lilly's investigational triple agonist, adding GCGR agonism to the dual mechanism of tirzepatide.
Glucagon receptor activation independently stimulates energy expenditure — particularly hepatic gluconeogenesis suppression and brown adipose tissue thermogenesis — through a mechanism distinct from both GIP and GLP-1 pathways. In the retatrutide phase 2 trial (Jastreboff et al., NEJM 2023), the 12mg dose produced up to 24.2% body weight reduction at 48 weeks in participants without type 2 diabetes — suggesting the addition of glucagon receptor agonism to the dual mechanism adds a further increment to the metabolic effect size. Retatrutide remains at phase 3 investigation and has not received regulatory approval.
For researchers studying incretin biology and metabolic signalling, the progression from semaglutide (GLP-1 mono) → tirzepatide (GIP+GLP-1 dual) → retatrutide (GIP+GLP-1+glucagon triple) represents a pharmacological toolkit for systematically isolating the contribution of each receptor system to overall metabolic outcomes. Pure Grade Labs supplies all three as research chemicals with batch-specific COAs.
In metabolic endocrinology research circles, the SURPASS-2 readout in 2021 created a specific kind of tension — not around the efficacy data, which was expected to show tirzepatide superior to semaglutide, but around the magnitude of the difference. At every dose level. Both endpoints. The question that kept appearing in discussion sections and conference Q&As was: which receptor is doing the extra work? Is GIP contributing proportionally to insulin secretion, to CNS satiety, to adipose tissue remodelling — or all three? The honest answer, in 2026, remains partially unresolved. Tirzepatide research has answered the "how much" question decisively. The "exactly how" question is still generating publishable findings.
GIP Receptor vs GLP-1 Receptor: Biology Comparison
The two incretin receptors engaged by tirzepatide differ substantially in their secretion biology, tissue expression, and downstream signalling. The table below summarises the key distinctions relevant to dual agonism research.
| Parameter | GIP Receptor (GIPR) | GLP-1 Receptor (GLP-1R) |
|---|---|---|
| Endogenous Ligand | GIP (42 amino acids, K-cell secretion) | GLP-1 (30–31 amino acids, L-cell secretion) |
| Primary Secretion Site | Duodenum and proximal jejunum (K-cells) | Distal small intestine and colon (L-cells) |
| Receptor Type | Gs-coupled GPCR | Gs-coupled GPCR |
| Primary Tissue Targets | Pancreatic beta cells, adipocytes, osteoblasts, CNS (hypothalamus, hippocampus) | Pancreatic beta cells, hypothalamus, brainstem, vagus nerve, gastric smooth muscle, cardiac tissue |
| Downstream Pathway | cAMP/PKA; beta-arrestin (adipocytes); GLUT4 translocation; FAO enzyme expression | cAMP/PKA; PI3K/Akt; POMC/CART activation; NPY/AgRP suppression |
| Incretin Effect Contribution | ~50% (historically, though blunted in obesity) | ~50% (maintained in obesity) |
| Satiety Mechanism | Hypothalamic GIPR activation; appetite suppression in rodent models; mechanism in humans partially characterised | Arcuate nucleus POMC/CART; brainstem NTS vagal integration; gastric motility reduction |
Frequently Asked Questions
What is Mounjaro and what is tirzepatide?
Mounjaro is the brand name under which tirzepatide was approved by the MHRA in the United Kingdom and the FDA in the United States for the treatment of type 2 diabetes. Tirzepatide is the International Nonproprietary Name (INN) of the molecule itself — a 39-amino acid synthetic dual GIP/GLP-1 receptor agonist developed by Eli Lilly. In research contexts, the molecule is referred to as tirzepatide regardless of brand name.
How does dual GIP/GLP-1 agonism differ from GLP-1 mono-agonism?
GLP-1 mono-agonists such as semaglutide activate only the GLP-1 receptor. Tirzepatide simultaneously activates both GLP-1R and the GIP receptor (GIPR). GIP receptor activation adds a distinct adipose tissue signalling pathway — mediated through GIPR expression in adipocytes — and a CNS satiety component at hypothalamic GIPR that GLP-1 mono-agonists cannot engage. Published clinical trials demonstrate this translates to larger metabolic effect sizes: SURMOUNT-1 (tirzepatide 15mg, 20.9% mean weight loss) versus STEP-1 (semaglutide 2.4mg, 17.4% mean weight loss).
What were the main findings of SURMOUNT-1?
SURMOUNT-1 (Jastreboff et al., NEJM 2022) enrolled 2,539 participants with obesity or overweight and followed them for 72 weeks. Mean body weight reductions at the three dose levels were 15.0% (5mg), 19.5% (10mg), and 20.9% (15mg) versus 3.1% for placebo. The 15mg group showed maximum reductions reaching 22.5% in higher-responding participants. At the time of publication, this represented the largest pharmacologically-driven weight reduction reported in any phase 3 clinical trial. For research purposes only. Tirzepatide is a prescription-only medication.
Is tirzepatide available in the UK?
Tirzepatide (Mounjaro) is approved as a prescription-only medication in the UK by the MHRA. It requires a valid prescription from a qualified prescriber for legal human use. Pure Grade Labs supplies tirzepatide as a research chemical for laboratory research only — not for human consumption and not as a substitute for the prescription medicine supply chain.
How does tirzepatide compare to retatrutide in research?
Retatrutide adds glucagon receptor (GCGR) agonism to the dual GIP/GLP-1 mechanism of tirzepatide. In a phase 2 trial published in NEJM 2023, retatrutide 12mg produced up to 24.2% body weight reduction at 48 weeks — suggesting that GCGR agonism adds a further increment to the metabolic effect size. Retatrutide is currently in phase 3 investigation and has not received regulatory approval.
Where can I find the published clinical trial data on tirzepatide?
The primary references for Mounjaro research are available on PubMed: SURMOUNT-1 (PMID: 35658024), SURPASS-1 (PMID: 34080030), SURPASS-2 (PMID: 34170647), and the dual mechanism review by Samms et al. in Cell Metabolism (PMID: 34289344). Additional ongoing trials are registered at ClinicalTrials.gov.
Research-Grade Tirzepatide — Pure Grade Standard
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Browse Research Compounds →Conclusion: Why Dual GIP/GLP-1 Agonism Matters for Research
Mounjaro research — centred on tirzepatide — has produced one of the most compelling pharmacological datasets of the past decade. The dual GIP/GLP-1 mechanism is not an incremental refinement of GLP-1 mono-agonism: it is a pharmacologically distinct signalling model that engages adipose tissue remodelling, central satiety circuits, and pancreatic insulin secretion through mechanisms that a single-receptor agonist cannot replicate. SURPASS-2 confirmed tirzepatide's superiority over semaglutide 1mg. SURMOUNT-1 documented up to 22.5% body weight reduction in 2,539 participants over 72 weeks.
For researchers studying the incretin axis, metabolic signalling, or comparative pharmacology of GLP-1 class compounds, tirzepatide provides an evidence base and mechanistic toolkit that positions it alongside semaglutide and retatrutide as essential reference compounds in the pharmacological progression from single to triple receptor agonism. Pure Grade Labs supplies all three as research chemicals with HPLC-verified purity and batch-specific Certificates of Analysis — for laboratory research only.
References
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216. PMID: 35658024
- Frias JP, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med. 2021;385(6):503-515. PMID: 34170647
- Rosenstock J, et al. Efficacy and Safety of a Novel Dual GIP and GLP-1 Receptor Agonist Tirzepatide in Patients With Type 2 Diabetes (SURPASS-1). JAMA. 2021;326(10):955-965. PMID: 34080030
- Samms RJ, et al. Functionally Biased GIPR Agonism Drives Weight Loss in Diet-Induced Obese Animals. Cell Metab. 2021;33(8):1550-1565. PMID: 34289344
- Müller TD, et al. Glucagon-like peptide 1 (GLP-1). Mol Metab. 2019;30:72-130. PMID: 31767182
- Jastreboff AM, et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. PMID: 37366315
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384(11):989-1002. PMID: 33567185
Disclaimer: Tirzepatide (Mounjaro) is a prescription-only medication in many jurisdictions including the United Kingdom. This article is published for research and educational purposes only. All content reflects published peer-reviewed clinical and preclinical literature. Pure Grade Labs supplies tirzepatide strictly as a research chemical for laboratory use — not for human consumption, not for therapeutic, diagnostic, or personal use. This content does not constitute medical advice. Researchers and purchasers are responsible for compliance with all applicable regulations in their jurisdiction. Always consult a qualified healthcare professional for any health-related decisions. For research purposes only. Not for human consumption.
Last Updated: May 2026