Tirzepatide vs cagrilintide

They share no receptors at all

These two compounds are frequently listed together, discussed together and compared as though they were competing options in one class. They are not in one class. They act on entirely unrelated receptor families and have no receptor in common.

Tirzepatide is an incretin analogue: an agonist at the GLP-1 and GIP receptors, both of which respond to gut hormones released in response to nutrients. Cagrilintide is an amylin analogue: an agonist at the amylin receptors and at the calcitonin receptor. Neither compound has any activity at the other's receptors.

So the comparison people want — which is better — has no pharmacological content. They are different mechanisms studied in overlapping contexts, and the reason they appear side by side is that the combination of an amylin receptor agonist with an incretin receptor agonist is itself a subject of published interest.

Side by side

They solved different engineering problems

Both molecules are stabilised analogues carrying a fatty-acid chain that allows reversible binding to serum albumin, which is a genuine similarity in design strategy. Beyond that the problems they had to solve were not the same.

For tirzepatide the obstacle was enzymatic. Native GIP and GLP-1 are inactivated within minutes by dipeptidyl peptidase-4, which cleaves near the amino terminus, so the sequence incorporates α-aminoisobutyric acid — a non-natural residue — where a cleavage site would otherwise be presented.

For cagrilintide the obstacle was physical. Native human amylin aggregates readily into insoluble fibrils, which makes the native sequence very difficult to formulate as a stable solution at all. The analogue's substitutions reduce that tendency. This is a formulation and physical-chemistry problem rather than a metabolic one, and it has no counterpart in the incretin analogues.

That difference persists into the laboratory. Aggregation assays — tracking the formation of ordered aggregates over time — are a standard part of characterising an amylin analogue and are simply not part of characterising an incretin analogue.

Why cagrilintide's receptors are described two ways

Cagrilintide is described in some places as an amylin analogue and in others as a calcitonin receptor agonist, which reads like an inconsistency and is not one.

The amylin receptors are not standalone proteins. They are complexes formed when the calcitonin receptor pairs with one of three receptor activity-modifying proteins, producing the AMY1, AMY2 and AMY3 subtypes. So the calcitonin receptor is a component of every amylin receptor, and a compound acting at amylin receptors is by construction acting at calcitonin-receptor-containing complexes.

The experimental consequence is that selectivity between the amylin subtypes and the bare calcitonin receptor is a real, measurable question rather than something the classification settles. Characterisation work builds a panel — the calcitonin receptor alone, and with each modifying protein — and assays the compound against each. Nothing comparable arises for tirzepatide, whose two receptors are separate proteins.

The cartridges are at opposite ends of the range

The Tirzepatide Pen 60 mg holds 60 mg at 20 mg/ml. The Cagrilintide Pen 10 mg holds 10 mg at 3.33 mg/ml. Same 3 ml cartridge, six times the mass and six times the concentration in one against the other — the largest such gap between any two single-compound pens in the catalogue.

This is exactly the case that makes unit price misleading. Comparing the two pens on their headline prices compares containers, not contents; comparing them on cost per milligram gives a figure that means something. The point is developed in what to check before ordering.

Storage is identical for both: 2–8 °C, protected from light, not frozen, for as long as the cartridge is held.

Common questions

Is cagrilintide better than tirzepatide?

The comparison has no pharmacological content, because the two share no receptors. Tirzepatide acts at the GLP-1 and GIP receptors; cagrilintide acts at the amylin receptors and the calcitonin receptor. They are different mechanisms studied in overlapping contexts, not competing options in one class.

Is cagrilintide a GLP-1 agonist?

No. It has no activity at the GLP-1, GIP or glucagon receptors. It acts at the amylin receptors — complexes of the calcitonin receptor with a receptor activity-modifying protein — and at the calcitonin receptor itself.

Why is cagrilintide described both as an amylin analogue and a calcitonin receptor agonist?

Because the amylin receptors are built from the calcitonin receptor plus an accessory protein, so both descriptions cover the same pharmacology. It also means selectivity between the amylin subtypes and the bare calcitonin receptor is a measurable question rather than one the classification settles.

Do the two compounds have anything in common?

A design strategy: both are stabilised analogues carrying a fatty-acid chain that allows reversible albumin binding. The problems they were stabilising against differ — enzymatic cleavage for tirzepatide, fibril formation for cagrilintide — and the latter has no counterpart among the incretin analogues.

Why are the two cartridges so different in strength?

The tirzepatide pen holds 60 mg at 20 mg/ml and the cagrilintide pen 10 mg at 3.33 mg/ml, in the same 3 ml volume — six times the mass and concentration. This is the clearest case in the catalogue where unit price misleads and cost per milligram is the figure to compare.

Products described in this guide

Supplied for laboratory research use only. UK delivery is free on every order, tracked as standard.

Tirzepatide Pen 60mg £170.00 Cagrilintide Pen 10mg £120.00 Retatrutide Pen 40mg (Reta Pen) £160.00

Research use only