What Is Tirzepatide? A Plain-English UK Research Guide
Tirzepatide is a synthetic 39-amino-acid peptide that activates two incretin receptors at the same time — GIP and GLP-1. That dual action is why the research literature often calls it a "twincretin", and it is the single biggest difference between tirzepatide and the GLP-1-only peptides such as semaglutide.
This page explains what it is, how it behaves in published research, what strengths exist, and how it sits next to semaglutide and retatrutide. Everything we supply is research-grade lyophilised peptide. For In Vitro Use Only — Not for Human Use.
Tirzepatide at a glance
| Peptide class | Dual GIP / GLP-1 receptor agonist |
| Length | 39 amino acids, C20 fatty diacid conjugated |
| Reported half-life | ~5 days (weekly research intervals) |
| Form supplied | Lyophilised powder, vial / pen / cartridge |
| Strengths | 20mg £90 · 40mg £140 · 60mg £170 |
| Purity | 99%+ HPLC, batch-matched COA |
| Intended use | In vitro laboratory research only |
How tirzepatide works
Incretins are gut hormones released after nutrient intake. Tirzepatide was engineered to engage two of those receptor pathways rather than one:
- GLP-1 receptor — the pathway semaglutide targets; associated in research with insulin response, gastric emptying and appetite signalling.
- GIP receptor — the additional pathway; studied for its role in insulin secretion and lipid handling in adipose tissue models.
The molecule is fatty-acid modified so it binds albumin, which is what extends its reported half-life to around five days and underpins the weekly dosing intervals used in published study protocols.
Tirzepatide vs semaglutide vs retatrutide
| Peptide | Receptors | Typical study range |
|---|---|---|
| Semaglutide | GLP-1 | 0.25 – 2.4mg weekly |
| Tirzepatide | GIP + GLP-1 | 2.5 – 15mg weekly |
| Retatrutide | GIP + GLP-1 + glucagon | 1 – 12mg weekly |
Because the receptor targets and dose ranges differ, milligram-for-milligram comparisons between these peptides are not meaningful. Read the full breakdowns: tirzepatide vs semaglutide and retatrutide vs tirzepatide.
How tirzepatide is supplied and reconstituted
Tirzepatide ships as a stable lyophilised (freeze-dried) powder. To bring it into solution, add a maximum of 3mL of bacteriostatic water per vial, slowly down the inside wall, then swirl until clear — never shake.
| Vial | Bac water | Concentration | 2.5mg on a U-100 |
|---|---|---|---|
| 20mg | 2mL | 10mg/mL | 25 units |
| 40mg | 3mL | 13.33mg/mL | ~19 units |
| 60mg | 3mL | 20mg/mL | 12.5 units |
Work any fill volume out instantly with our free reconstitution calculator, or browse tirzepatide vials and pre-filled Tirz pens.
Legal status and intended use
Tirzepatide can be bought and held in the UK for laboratory research. The material we supply is not a licensed medicine, carries no medical claims, and must not be used in humans or animals. For In Vitro Use Only — Not for Human Use. You must be 18 or over to order.
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View full shopFrequently asked questions
What is tirzepatide?
Tirzepatide is a synthetic 39-amino-acid peptide that acts on two incretin receptors at once — GIP and GLP-1. It was first characterised as a dual agonist, which is what separates it from single-receptor GLP-1 peptides such as semaglutide. We supply it as a lyophilised research-grade peptide vial. For In Vitro Use Only — Not for Human Use.
How does tirzepatide work?
In published research it binds both the GIP and the GLP-1 receptor, producing incretin signalling that in study models affects insulin response, gastric emptying rate and appetite signalling pathways. The dual mechanism is why it is often described as a 'twincretin' in the literature.
Is tirzepatide a peptide or a drug?
Chemically it is a peptide — a 39-amino-acid chain with a C20 fatty diacid moiety. In licensed medicine form it is a prescription product; the material we sell is research-grade lyophilised peptide supplied strictly for in vitro laboratory research, not for human or animal use.
What is the half-life of tirzepatide?
Published pharmacokinetic research reports a half-life of roughly 5 days, which is why study protocols in the literature typically use weekly intervals.
What strengths does tirzepatide come in?
We stock research vials at 20mg (£90), 40mg (£140) and 60mg (£170). The 60mg vial is the lowest cost per mg at about £2.83/mg. Each can also be prepared as a pre-filled V2 Quick Pen or cartridge using the Format selector.
How do you reconstitute tirzepatide?
Add up to a maximum of 3mL of bacteriostatic water per vial, running it slowly down the inside wall of the vial rather than onto the powder, then swirl gently until clear. Never shake. 20mg in 2mL gives 10mg/mL; 40mg in 3mL gives 13.33mg/mL; 60mg in 3mL gives 20mg/mL.
Is tirzepatide stronger than semaglutide?
They are not directly interchangeable. Tirzepatide is a dual GIP/GLP-1 agonist while semaglutide targets GLP-1 alone, and the research dose ranges differ substantially — semaglutide studies typically run 0.25–2.4mg weekly against 2.5–15mg weekly for tirzepatide. Comparing them by milligrams alone is misleading.
Is tirzepatide the same as retatrutide?
No. Retatrutide is a triple agonist acting on GIP, GLP-1 and glucagon receptors, so it adds a third pathway that tirzepatide does not have. Both are supplied here as research peptides only.
Is it legal to buy tirzepatide in the UK?
Tirzepatide may be bought and possessed in the UK for laboratory research purposes. It is not a licensed medicine in the form we supply and is not intended for human or animal use. For In Vitro Use Only — Not for Human Use.
How should tirzepatide be stored?
Keep lyophilised vials cool, dark and dry — a fridge at 2–8°C is ideal. Once reconstituted, store refrigerated at 2–8°C away from light, never frozen, and treat as stable for roughly 4 weeks.
Disclaimer: All products sold by Peptides UK 4U are for laboratory and research purposes only. They are not intended for human or animal consumption, diagnosis, treatment or prevention of any disease.