Tirzepatide 20 mg

Tirzepatide — 10 / 20 mg

Purity: ≥98% (HPLC)
Form: lyophilized powder, 3 ml vial
Storage: −20 °C (before opening), +2…+8 °C (after reconstitution, no more than 28 days)
Verification: Janoshik Analytical (Czech Republic) — independent blind test of every batch
Synonyms: Tirzepatide, LY3298176, Tirzepatide
Developer: Eli Lilly and Company (USA)
Status: Approved by the FDA as Mounjaro® (type 2 diabetes) and Zepbound® (obesity)

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Contents

1. What is Tirzepatide?
2. Why Tirzepatide attracts researchers' attention
3. Two receptors — in plain terms
4. The SURMOUNT program — key studies
5. Tirzepatide vs. Semaglutide — a direct comparison
6. Insulin sensitivity and beta cells
7. Safety and side-effect profile
8. Where Tirzepatide stands today
9. Sources

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1. What is Tirzepatide?

Tirzepatide is the world's first dual agonist of the GIP and GLP-1 receptors, developed by Eli Lilly. It is a synthetic peptide that simultaneously activates two incretin hormone receptors — a mechanism that had not been implemented in any molecule before Tirzepatide.

The peptide is administered subcutaneously once a week. The molecule is engineered on the basis of the native GIP sequence with the addition of a fragment that provides activity at the GLP-1 receptor. Conjugation with a fatty-acid fragment (C20) provides a long half-life — about 5 days.

Tirzepatide is one of the most clinically studied molecules of the past decade. The SURMOUNT (obesity) and SURPASS (type 2 diabetes) programs together include more than 5,000 participants.

For research use only. Not a medicinal product. Not intended for use in humans or animals.

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2. Why Tirzepatide attracts researchers' attention

Tirzepatide became the first molecule to show, in clinical studies, results that were previously achievable only through surgery:

• −22.5% body weight over 72 weeks at the maximum dose in the SURMOUNT-1 study (2,539 participants, NEJM, 2022) [1]. That is about 24 kg for a person weighing 105 kg.

• 96% of participants on the 10 and 15 mg doses lost ≥5% of body weight — the threshold considered clinically significant [1].

• Superiority over semaglutide — in the direct comparative study SURMOUNT-5, tirzepatide showed a statistically significantly greater reduction in weight than semaglutide (Wegovy) over 72 weeks [5].

• Dual mechanism: tirzepatide acts on two receptors at once (GIP + GLP-1), whereas semaglutide acts on only one (GLP-1). Researchers believe that it is precisely this combination that provides a synergistic effect [2].

All of the data listed were obtained within randomized controlled studies. The pharmaceutical version of tirzepatide is approved by the FDA. The research version presented in the LONGIVIYA catalog is intended exclusively for laboratory purposes.

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3. Two receptors — in plain terms

To understand why tirzepatide works differently from semaglutide, one needs to know about two hormones.

GLP-1 (glucagon-like peptide-1). Produced by the intestine after eating. It sends the brain a satiety signal: "Stop eating." It slows gastric emptying — the feeling of fullness lasts longer. Semaglutide works at this receptor — and it does so well. But at only one receptor.

GIP (glucose-dependent insulinotropic peptide). The second satiety hormone, which long remained in the shadow of GLP-1. GIP enhances insulin secretion in response to food, improves the sensitivity of cells to insulin, and participates in fat metabolism. In preclinical models, adding GIP agonism to GLP-1 led to a more pronounced reduction in body weight than GLP-1 alone [2].

Tirzepatide is the first molecule to combine both mechanisms in a single peptide. Its affinity for the GIP receptor equals that of native GIP, while its affinity for GLP-1 is approximately 5 times lower than that of native GLP-1 [2]. Nevertheless, this is sufficient for potent clinical activity at both receptors.

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4. The SURMOUNT program — key studies

The SURMOUNT program is a series of Phase 3 studies of tirzepatide in obesity, begun in 2019. More than 5,000 participants.

SURMOUNT-1 (NEJM, 2022) — the main study

2,539 participants with a BMI ≥30 (or ≥27 in the presence of comorbid conditions), without type 2 diabetes, 72 weeks [1].

Dose	Body weight reduction	Lost ≥5%	Lost ≥10%	Lost ≥20%
5 mg	−16.0% (16 kg)	89%	73%	50%
10 mg	−21.4% (22 kg)	96%	86%	74%
15 mg	−22.5% (24 kg)	96%	89%	78%
Placebo	−2.4% (2 kg)	28%	10%	2%

SURMOUNT-3 — after intensive lifestyle modification

Participants first completed a 12-week program of intensive lifestyle modification. Those who lost ≥5% of weight then received tirzepatide or placebo over 72 weeks [6]. Result: 87.5% on tirzepatide lost ≥5% additional weight vs. 16.5% on placebo.

SURMOUNT-5 — direct comparison with semaglutide

The first direct (head-to-head) comparison of tirzepatide and semaglutide. 751 participants, 72 weeks, open-label study [5]. Tirzepatide demonstrated a statistically significantly greater reduction in body weight at the maximum doses.

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5. Tirzepatide vs. Semaglutide — a direct comparison

Semaglutide (Ozempic, Wegovy) is a GLP-1 mono-agonist. Tirzepatide (Mounjaro, Zepbound) is a dual GIP + GLP-1 agonist. They are often compared, and data for comparison are now available both from parallel studies and from a direct head-to-head.

Parameter	Semaglutide 2.4 mg	Tirzepatide 15 mg
Receptors	GLP-1	GIP + GLP-1
Weight reduction (Phase 3)	~15–17%	~20–22.5%
Difference in direct comparison	—	+5.5 kg more than semaglutide [3]
FDA status (obesity)	Approved (Wegovy)	Approved (Zepbound)
FDA status (type 2 diabetes)	Approved (Ozempic)	Approved (Mounjaro)
Administration	Once a week	Once a week

Researchers attribute tirzepatide's advantage to the additional action on the GIP receptor: the expression patterns of GIP receptors in the brain do not fully coincide with those of GLP-1, which may provide an additional contribution to the regulation of energy balance [5].

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6. Insulin sensitivity and beta cells

In addition to the reduction in body weight, the studies have described a pronounced effect of tirzepatide on metabolic parameters.

In the SURPASS program (type 2 diabetes), a reduction in HbA1c of up to −2.07% was observed at the maximum dose — a result exceeding that of semaglutide in the direct comparison SURPASS-2 [3].

In a post hoc analysis of SURMOUNT-1, researchers studied the effect of tirzepatide on the function of the pancreatic beta cells and on insulin sensitivity in people without diabetes [4]. It has been described that the improvement in insulin sensitivity per unit of weight lost was more pronounced with tirzepatide than with semaglutide — which may indicate an independent contribution of the GIP component.

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7. Safety and side-effect profile

The side-effect profile of tirzepatide has been described in multiple Phase 3 studies and is consistent with the incretin drug class. The most frequent adverse events are gastrointestinal: nausea, diarrhea, decreased appetite, constipation. In most cases they were mild or moderate in severity and were transient in nature, predominantly during the dose-escalation period [1][6].

In a separate post hoc analysis of SURMOUNT, the psychiatric safety of tirzepatide was studied. No significant increase in the frequency of suicidal ideation or other serious psychiatric events compared with placebo was identified [7].

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8. Where Tirzepatide stands today

Indication	Status
Obesity (Zepbound)	Approved by the FDA (November 2023)
Type 2 diabetes (Mounjaro)	Approved by the FDA (May 2022)
NASH / MASLD	Phase 2, studies ongoing
Obstructive sleep apnea	Approved by the FDA (2025)
Chronic kidney disease	Studies planned
Cardiovascular outcomes in obesity	Studies planned
Weight-loss maintenance (SURMOUNT-MAINTAIN)	Phase 3, enrollment ongoing

Tirzepatide is one of the most rapidly developing peptides in the history of pharmaceuticals: from the first Phase 1 study in 2018 to FDA approval for two indications in less than 5 years.

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Sources

1. Jastreboff A.M. et al. Tirzepatide Once Weekly for the Treatment of Obesity. N. Engl. J. Med., 387(3): 205–216, 2022. PubMed

2. Coskun T. et al. LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: from discovery to clinical proof of concept. Mol. Metab., 18: 3–14, 2018. PubMed

3. Frías J.P. et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N. Engl. J. Med., 385: 503–515, 2021. PubMed

4. SURMOUNT-1 post hoc analysis: Tirzepatide Treatment and Associated Changes in β-Cell Function and Insulin Sensitivity. Diabetes Care, 48(9): 1622–1630, 2025. Diabetes Journals

5. SURMOUNT-5: Tirzepatide vs Semaglutide head-to-head, 72 weeks. N. Engl. J. Med., 2025. Eli Lilly

6. Wadden T.A. et al. Tirzepatide after intensive lifestyle intervention in adults with overweight or obesity: the SURMOUNT-3 phase 3 trial. Nat. Med., 29: 2909–2918, 2023. PMC

7. Wadden T.A. et al. Psychiatric Safety of Tirzepatide in People With Obesity: A Post Hoc Analysis of SURMOUNT. Obesity, 34(3): 565–578, 2026. PubMed

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This material was prepared by the LONGIVIYA editorial team on the basis of published scientific research. The information is for educational purposes only and is not a medical recommendation.

For research use only. Not a medicinal product. Not intended for use in humans or animals. Independent verification of every batch: Janoshik Analytical (Czech Republic).