Tirzepatide (GLP-1+GIP) 10 mg PEN

Regulatory framework — a critical distinction

GLP-1+GIP 10 mg PEN is a research reagent (Research Use Only) in a pre-dissolved pen. The active substance belongs to the class of dual GLP-1R and GIPR agonists — the same class as tirzepatide (LY3298176), registered by Eli Lilly as the medicinal product Mounjaro (type 2 diabetes, FDA 2022, EMA 2022) and Zepbound (obesity, FDA 2023, EMA 2024). These two instances of the same chemical class represent two distinct regulatory frameworks — the RUO pen in the One Peptides catalog is not the medicinal product Mounjaro or Zepbound and is not subject to pharmaceutical regulation. The active substance may be tirzepatide or another dual GLP-1/GIP analog — in either case the status is RUO, not a medicinal product.

A dual GLP-1R and GIPR agonist represents an evolutionary step from monoagonists (semaglutide, liraglutide) toward molecules that simultaneously activate two signaling pathways of the incretin axis. The pharmacodynamic profile of the class was described by Coskun et al. (2018) in Molecular Metabolism for tirzepatide (LY3298176, Eli Lilly), and the SURPASS and SURMOUNT programs produced phase III data published in NEJM. Broader context on the incretin axis is compiled in the guide on GLP-1 peptides in metabolism. The dual agonist is the most clinically advanced variant of incretin polypharmacology approved as a medicinal product.

The 10 mg variant is a pen with a higher peptide content — for laboratory protocols requiring a larger quantity of reagent than the standard 5 mg. In the One Peptides catalog, the GLP-1+GIP class appears in a distinct regulatory framework — as an RUO research reagent in a pre-dissolved pen. This format simplifies laboratory work: no need to reconstitute a lyophilizate, with precise withdrawal of the peptide under controlled conditions.

What is GLP-1+GIP — a single-molecule dual-agonist peptide

GLP-1+GIP is a single peptide molecule that simultaneously activates two incretin receptors — GLP-1R and GIPR. Importantly, the dual-agonist peptide is not a mixture of two separate peptides, but a single amino acid sequence with affinity spanning both receptors.

The best-studied representative of the class is tirzepatide (LY3298176), developed by Eli Lilly — a sequence of approximately 39 amino acids, molecular mass approximately 4813 Da. The molecule combines elements of GIP and GLP-1 in a single chain, with C20 fatty acid acylation (γ-Glu-2xOEG-C20 linker) and reversible binding to serum albumin. Albumin binding acts as a reservoir that extends the half-life to approximately 5 days — the once-weekly schedule in the Mounjaro and Zepbound clinical protocols. The full profile of this molecule is discussed in the analysis of tirzepatide — dual GIP/GLP-1 agonist.

Chemical characterization

Mechanism of action — why two receptors

Activation of GLP-1R triggers the profile known from semaglutide-class monoagonists: glucose-dependent insulin secretion in β cells, suppression of glucagon secretion in α cells, slowing of gastric emptying, and reduction of appetite through central action in the arcuate nucleus of the hypothalamus. The mechanism is glucose-dependent — under normoglycemia, insulin secretion is not significantly stimulated.

Activation of GIPR adds a second layer: potentiation of insulin secretion in β cells, modulation of adipose tissue metabolism, lipolysis, and regulation of energy storage. Synergistic activation of both receptors is reported in the literature as responsible for the additional metabolic effects of dual agonists relative to mono-GLP-1. The mechanism of the GLP-1 / GIP / glucagon axis is compiled in the article on how incretins regulate metabolism.

In the pivotal head-to-head trial SURPASS-2 (Frías et al., NEJM 2021), tirzepatide was compared directly with semaglutide 1 mg in type 2 diabetes — the dual agonist was reported with greater reduction of HbA1c and body weight across all tested doses. The SURPASS and SURMOUNT programs provided the phase III data underlying the registration of Mounjaro and Zepbound.

GLP-1+GIP PEN RUO vs Mounjaro / Zepbound — the fundamental difference

The Eli Lilly pen is a medicinal product with a patient leaflet, SmPC, and EMA pharmacovigilance oversight. The RUO pen at One Peptides is a chemical reagent with analytical documentation. Belonging to the same chemical class does not negate the distinction between regulatory frameworks.

Position in the classification of incretin peptides

The monoagonist (semaglutide) acts solely on GLP-1R. The dual agonist (tirzepatide / GLP-1+GIP class) adds GIPR and is the only incretin dual agonist approved as a medicinal product. The tri-agonist (retatrutide LY3437943) adds a third receptor — the glucagon receptor (GCGR) — and remains in phase III of the TRIUMPH program without registration.

Positioning of variants in the One Peptides catalog — 10 mg vs 5 mg vs vial

In the One Peptides catalog, the GLP-1+GIP class is available in several variants constituting distinct SKUs:

Analytical quality is identical across all variants: HPLC ≥98%, MS, COA per batch, cold chain 2–8°C. The 10 mg variant differs from the 5 mg only in the peptide content of the pen — the active substance, pharmacological class, and control standard are the same. The choice of content depends on the scale of the research protocol: a higher content reduces the frequency of pen replacement in longer experiments or series with a larger number of samples.

Applications in scientific research

• Pharmacology of the incretin axis — receptor activity, selectivity toward GLP-1R and GIPR, EC50 in cell cultures (cAMP reporters, β-arrestin).
• Animal models — DIO mice, ob/ob, db/db, Zucker rats. Endpoints: body weight, composition (DEXA, NMR), OGTT/ITT, HOMA-IR, lipid profile.
• Pharmacokinetics — PK profile of acylated analogs, albumin-binding kinetics, effect of the C18 vs C20 chain.
• Comparative analyses — head-to-head with mono-GLP-1 (semaglutide, liraglutide), the tri-agonist (retatrutide LY3437943), and native GLP-1/GIP in SAR studies.

One Peptides quality specification

• HPLC ≥98% — main peak area ≥98% of the sum of areas (liquid chromatography with UV detection).
• MS confirmation — confirmation of peptide identity by molecular mass.
• COA per batch — certificate of analysis for each batch (theoretical/measured mass, HPLC profile, synthesis date, batch number).
• Cold chain 2–8°C — refrigerated chain with monitoring from synthesis to delivery.
• Batch traceability — batch number in three places: pen label, invoice, COA.

Working with the pre-dissolved pen in a laboratory protocol

The guide below describes the technical handling of the pen in the context of a reagent for laboratory research — it is not an instruction for administration in humans or animals.

Pen content. GLP-1+GIP PEN 10 mg contains 10 mg of pre-dissolved peptide in typically about 2 mL of solution (details in the batch COA).

Working with the pen. Withdraw the solution with a laboratory syringe or an applicator with microliter precision. The solution should be clear — turbidity, sediment, or a change in color is a signal that the batch is not suitable for further work.

Working solutions. For in vitro receptor assays, the picomolar-to-nanomolar scale is standard. Serial dilutions in PBS at pH 7.4 or buffers compatible with the experimental system.

Stability. Unopened pen: typically up to 24 months at 2–8°C, protected from light (details in the COA). After first opening: typically up to 28 days at 2–8°C. Avoid freeze-thaw cycles.

The peptide calculator facilitates conversion of the stock concentration from the pen to the desired working concentration. This is not an instruction for administration in humans — the clinical tirzepatide schedules in the Mounjaro and Zepbound SmPCs pertain solely to the Eli Lilly medicinal products.

Regulatory status — GLP-1+GIP PEN, tirzepatide, incretin-class medicinal products

GLP-1+GIP PEN (this product) — a Research Use Only research reagent in the chemical reagent trade in the EU. Label “For research use only. Not for human use”. It is not a medicinal product, dietary supplement, or foodstuff. It holds no EMA or FDA marketing authorization as a medicinal product.

Tirzepatide as a medicinal product (Eli Lilly): Mounjaro — type 2 diabetes (FDA 2022, EMA 2022); Zepbound — obesity (FDA 2023, EMA 2024). Both products available by prescription only.

Registration landscape. Only semaglutide (mono-GLP-1, Novo Nordisk) and tirzepatide (dual GLP-1/GIP, Eli Lilly) from the incretin peptide class hold the status of medicinal products registered by the EMA and FDA. Retatrutide (tri, LY3437943) and earlier experimental dual agonists remain in circulation solely as RUO reagents.

WADA. Peptides from the GLP-1 and GIP agonist class are not directly listed on the current WADA Prohibited List. The status may change in subsequent editions — verification of current guidelines rests with the researcher.

Frequently asked questions

How does the 10 mg variant differ from the 5 mg?

Solely in the peptide content of the pen: 10 mg vs 5 mg. The active substance (tirzepatide-class dual GLP-1/GIP agonist), pharmacological class, structural modifications, and quality control standard (HPLC ≥98%, MS, COA per batch) are identical. The 10 mg variant is intended for protocols requiring a larger quantity of reagent — it reduces the frequency of replacing the 5 mg pen in longer or more numerous experimental series.

Is GLP-1+GIP PEN the medicinal product Mounjaro or Zepbound?

No. GLP-1+GIP PEN is an RUO research reagent. Mounjaro and Zepbound are Eli Lilly medicinal products with a full EMA and FDA registration dossier, available by prescription only under physician supervision. The active substance may belong to the same chemical class (dual GLP-1/GIP agonist, specifically tirzepatide), yet the RUO pen and the pharmaceutical pen originate from two distinct regulatory frameworks.

How does GLP-1+GIP PEN differ from tirzepatide in clinical trials?

The pharmacological class is the same — a dual GLP-1R and GIPR agonist. The differences concern the regulatory framework and intended use. Clinical trials of tirzepatide (SURPASS, SURMOUNT) were conducted under EMA and FDA pharmacovigilance with the Eli Lilly medicinal product. The RUO PEN functions as a reagent for laboratory research.

Why is the dual agonist better reported than mono-GLP-1?

In the head-to-head SURPASS-2, tirzepatide was compared with semaglutide 1 mg in type 2 diabetes — the dual agonist was reported with greater reduction of HbA1c and body weight across all doses. The mechanistic argument: synergistic activation of GLP-1R + GIPR produces a stronger effect on insulin secretion and adipose tissue metabolism.

How long does the pen retain activity after first opening?

Typically up to 28 days at 2–8°C from first withdrawal. Detailed stability data in the batch COA. Avoid freeze-thaw cycles.

Are GLP-1 and GIP on the WADA list?

The current WADA Prohibited List does not directly list GLP-1 or GIP agonists as separate categories. The status may change in subsequent editions — verification of current guidelines rests with the researcher.

References

1. Coskun T et al. (2018). LY3298176, a novel dual GIP and GLP-1 receptor agonist for type 2 diabetes (discovery to clinical proof of concept)
2. Frías JP et al. (2021). Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2)
3. Min T, Bain SC (2021). The Role of Tirzepatide in the Management of Type 2 Diabetes (SURPASS Review)
4. Wilding JPH et al. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP-1)
5. Marso SP et al. (2016). Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6)

Research Use Only chemical reagent. GLP-1+GIP 10 mg PEN is not a medicinal product, dietary supplement, or foodstuff. It is not intended for administration to humans or animals outside a controlled experimental setting. Do not confuse GLP-1+GIP PEN RUO with the Eli Lilly dual GLP-1/GIP class medicinal products — Mounjaro and Zepbound. The active substance may belong to the same chemical class (dual GLP-1/GIP agonist, specifically tirzepatide LY3298176), yet the RUO pen and the pharmaceutical pen originate from two distinct regulatory frameworks. The information is educational and scientific in nature — it does not constitute medical advice or an instruction for administration.