Tirzepatide

Tirzepatide — Dual GIP/GLP-1 Receptor Agonist Research Peptide

Tirzepatide is a synthetic 39-amino-acid peptide built on the backbone of native glucose-dependent insulinotropic polypeptide (GIP) and engineered so that it also activates the glucagon-like peptide-1 (GLP-1) receptor. Two non-natural aminoisobutyric acid residues protect it from DPP-4 cleavage, the C-terminus is amidated, and a C20 fatty diacid chain attached through a linker at lysine 20 binds serum albumin to extend its circulating life. It was developed by Eli Lilly under the code LY3298176 and is the active ingredient in the registered medicines Mounjaro and Zepbound. It is usually written as tirzepatide peptide, frequently misspelled tirzepetide or terzepatide, and shortened to Tirz in online discussion.

Tirzepatide is studied in research models for glycaemic regulation, body-weight and adiposity control, and whole-body energy metabolism, with further programs examining cardiovascular outcomes, obstructive sleep apnoea, heart failure with preserved ejection fraction and liver fat. It is a dual incretin agonist: it binds the GIP receptor with an affinity close to that of native GIP and the GLP-1 receptor with somewhat lower affinity, driving cyclic AMP signalling in pancreatic islets, adipose tissue and the appetite-regulating centres of the brain.

Omega Peptides Australia supplies tirzepatide as a high-purity (≥99% HPLC), COA-verified lyophilised powder in 10mg and 30mg research vials. Orders placed before 12pm are dispatched the same day from within Australia, and the certificate for every batch is published in our COA library.

Key research areas

• Glycaemic regulation. The SURPASS Phase 3 clinical program evaluated tirzepatide in type 2 diabetes against placebo, insulin analogues and a GLP-1 receptor agonist. Research models examine glucose-dependent insulin secretion from beta cells, suppression of glucagon release and improvements in insulin sensitivity that appear to be greater than GLP-1 receptor agonism alone can explain.
• Body weight and adiposity. The SURMOUNT Phase 3 program studied tirzepatide in obesity with and without diabetes. Laboratory work investigates reduced energy intake through central appetite pathways, slowed gastric emptying, and a GIP-receptor contribution in adipose tissue that may improve lipid handling and reduce ectopic fat.
• Incretin receptor pharmacology. Tirzepatide is a useful tool compound for dissecting the two incretin receptors. It behaves as a full agonist at the GIP receptor and a biased agonist at the GLP-1 receptor, favouring cyclic AMP production over beta-arrestin recruitment, which is thought to reduce receptor internalisation and sustain signalling.
• Cardiovascular and renal outcomes. Cardiovascular outcome trials and secondary analyses have examined blood pressure, lipid profiles, inflammatory markers and albuminuria. Preclinical models study whether the dual mechanism affects cardiac metabolism independently of weight change.
• Sleep apnoea and heart failure. Clinical programs have investigated tirzepatide in moderate-to-severe obstructive sleep apnoea and in heart failure with preserved ejection fraction in the setting of obesity, two conditions closely linked to excess adiposity.
• Liver fat and steatohepatitis. Phase 2 work has assessed liver fat content and histological resolution in metabolic dysfunction-associated steatohepatitis, and rodent models explore hepatic lipid metabolism and fibrosis markers during dual incretin agonism.

How tirzepatide works

Native GIP and GLP-1 are gut hormones released after a meal. Tirzepatide mimics both at once. At the GLP-1 receptor it stimulates glucose-dependent insulin release, suppresses glucagon, slows gastric emptying and reduces appetite. At the GIP receptor it adds further insulinotropic drive and acts in adipose tissue, where GIP receptor signalling is linked to lipid storage and insulin sensitivity. The combination is described as imbalanced agonism because the GIP receptor is engaged more strongly than the GLP-1 receptor, and the GLP-1 receptor signalling is biased toward cyclic AMP with less beta-arrestin recruitment.

The C20 fatty diacid side chain binds albumin, giving a plasma half-life of roughly five days, which is why clinical programs use once-weekly administration. The peptide is cleared by proteolytic degradation of its amide bonds and beta-oxidation of the fatty acid chain. Tirzepatide differs from single-target GLP-1 receptor agonists such as semaglutide by adding the GIP component, and from retatrutide, a triple agonist that also stimulates the glucagon receptor. Our retatrutide vs tirzepatide page compares the two in detail.

Specifications

Available sizes and pricing

Tirzepatide is supplied in two vial sizes so that a laboratory can match the quantity to the scale of its work. The 30mg vial lowers the per-mg cost by around 40 percent compared with the 10mg vial, which suits longer or multi-arm research programs.

• 10mg vial — $119.99 (about $12.00 per mg)
• 30mg vial — $219.99 (about $7.33 per mg)

Quality and COA verification

Every batch of tirzepatide is independently tested by Janoshik Analytical, with HPLC used to confirm purity of 99 percent or higher and mass spectrometry used to confirm identity against the expected molecular weight. A Certificate of Analysis is issued for every batch and published in our COA library, so the report for the vial in hand can be checked before the seal is broken. Vials are filled and sealed under sterile conditions, and the peptide is lyophilised because a dry powder resists hydrolysis and oxidation far better than a solution. Orders are packed with cushioning for domestic transit and shipped from Australian stock, which keeps time in transit short and avoids the temperature swings of international freight.

Frequently bought together

• Bacteriostatic Water (10mL) — $29.99, the standard diluent for reconstituting lyophilised peptides.
• MOTS-C (10mg) — $99.99, a mitochondrial-derived peptide used in parallel metabolic research models.
• AOD-9604 (5mg) — $89.99, a growth hormone fragment studied in lipid metabolism research.

Research guides

• Tirzepatide research guide
• Retatrutide vs tirzepatide
• Peptide storage guide
• COA testing explained
• Peptide reconstitution calculator

Frequently asked questions

What is Tirz?
Tirz is the shorthand used in online discussion for tirzepatide, the dual GIP and GLP-1 receptor agonist peptide developed by Eli Lilly. Searches for Tirz, Tirz peptide or Tirz Australia all refer to the same 39-amino-acid compound. Omega Peptides Australia supplies it as a lyophilised research peptide in 10mg and 30mg vials for laboratory use only.

What is tirzepatide?
Tirzepatide is a synthetic peptide modelled on the gut hormone GIP and modified to activate both the GIP receptor and the GLP-1 receptor. It carries a fatty diacid chain that binds albumin and gives it a half-life of about five days. It is studied in research models of glucose regulation, body-weight control and related metabolic conditions, and it is the active ingredient of the registered medicines Mounjaro and Zepbound.

What is tirzepatide also known as?
Tirzepatide was developed under the code LY3298176 and is marketed as a medicine under the brand names Mounjaro and, in some countries, Zepbound. It is commonly called tirzepatide peptide or simply Tirz, and it is often misspelled tirzepetide or terzepatide. All of these terms describe the same dual incretin receptor agonist.

How does tirzepatide work?
Tirzepatide activates two incretin receptors at the same time. Through the GLP-1 receptor it promotes glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying and reduces appetite signalling. Through the GIP receptor it adds insulinotropic drive and acts on adipose tissue, where it is thought to improve lipid handling and insulin sensitivity. Its albumin-binding side chain extends the plasma half-life to roughly five days.

What does the research show about tirzepatide?
Two large Phase 3 programs, SURPASS in type 2 diabetes and SURMOUNT in obesity, reported substantial improvements in glycaemic markers and body weight compared with placebo and active comparators. Further clinical and preclinical work has examined cardiovascular outcomes, obstructive sleep apnoea, heart failure with preserved ejection fraction and liver fat. Laboratory studies continue to explore how the GIP component contributes beyond GLP-1 receptor agonism alone.

Can I buy tirzepatide at Chemist Warehouse or a pharmacy in Australia?
Yes, as a registered medicine. Tirzepatide is TGA-registered under the brand Mounjaro (Eli Lilly) and is dispensed by Chemist Warehouse and other Australian pharmacies only on a valid prescription. The lyophilised research-grade tirzepatide sold by Omega Peptides Australia is a different product, supplied strictly for laboratory use and never as a substitute for a prescribed medicine.

Can Australian compounding pharmacies supply tirzepatide?
Compounding pharmacies in Australia prepare medicines only for an individual patient on a practitioner's prescription and do not sell peptides to the public. No. From 1 October 2024 the Australian Government removed GLP-1 receptor agonists, including tirzepatide and semaglutide, from the pharmacy compounding exemption, so compounding pharmacies can no longer prepare replica tirzepatide products. Prescribed tirzepatide is available only as the registered Mounjaro product. Research suppliers such as Omega Peptides Australia supply the lyophilised research compound for in-vitro laboratory work, which is an entirely separate category.

How do you reconstitute tirzepatide?
Add bacteriostatic water slowly down the inside wall of the vial rather than directly onto the powder, then swirl gently until the solution is clear. Do not shake, because agitation can shear and aggregate long peptides. The reconstitution calculator works out the volume needed for a target concentration. Refrigerate the reconstituted vial at 2–8°C and use it within 28 days.

How should tirzepatide be stored?
Keep the lyophilised powder sealed at 2–8°C for short-term storage or at −20°C for long-term storage, protected from light and moisture. Avoid repeated freeze-thaw cycles, which degrade peptides. Once reconstituted, store the solution at 2–8°C and use it within 28 days. Bacteriostatic water contains 0.9 percent benzyl alcohol, which suppresses microbial growth during this period.

Where can I buy tirzepatide in Australia?
Omega Peptides Australia holds tirzepatide in domestic stock and dispatches orders placed before 12pm on the same business day. Every batch is COA-verified by an independent laboratory, and the certificates are published online. The 10mg and 30mg vials can be ordered directly from this page, or you can browse the full range of research peptides in Australia.

What does tirzepatide cost in Australia?
Research-grade tirzepatide from Omega Peptides Australia costs $119.99 for a 10mg vial, which is about $12.00 per mg, and $219.99 for a 30mg vial, which is about $7.33 per mg. The larger vial lowers the per-mg cost by roughly 40 percent. Bacteriostatic water for reconstitution is sold separately in 3mL and 10mL sizes.

How do I get tirzepatide online in Australia?
Choose the 10mg or 30mg vial on this product page, add it to your cart and complete checkout. Orders are shipped with tracked domestic delivery in discreet, unbranded packaging. Orders placed before 12pm are dispatched the same business day from within Australia, and a tracking number is emailed once the parcel is lodged.

Is tirzepatide legal in Australia?
Omega Peptides Australia supplies tirzepatide strictly for lawful in-vitro laboratory research. The research-grade compound sold here is not approved by the TGA for human or veterinary use and is not sold as a medicine or supplement; only the registered Mounjaro product dispensed on prescription is a medicine. Purchasers are responsible for ensuring their intended use complies with all applicable laws.

What is the difference between tirzepatide and retatrutide?
Tirzepatide is a dual agonist that activates the GIP and GLP-1 receptors. Retatrutide is a triple agonist that adds the glucagon receptor, which is expected to increase energy expenditure and hepatic fat oxidation alongside the appetite and insulin effects. Tirzepatide is a registered medicine with completed Phase 3 programs, whereas retatrutide remains in late-stage clinical development. See our retatrutide vs tirzepatide comparison for a side-by-side summary.

⚠ For in-vitro research and laboratory use only. Not for human or veterinary use.