GLP-1/GIP/Glucagon: The tri-agonist and multi-agonist peptide landscape in 2026

The past three years have shifted the obesity and metabolic peptide research space decisively toward multi-receptor agonism. The single-receptor GLP-1 agonists that dominated the 2015-2022 era (liraglutide, dulaglutide, semaglutide) are still the reference standard, but the leading edge of research is now firmly in the multi-receptor space. This post is a state-of-the-field overview of the multi-agonist peptides currently in clinical development, organized by receptor combination.

The receptors involved

Before mapping the field, a brief reference on the four receptors that matter here:

GLP-1 receptor (GLP-1R): Beta cells, hindbrain, gastric smooth muscle. Well-characterized incretin pathway.
GIP receptor (GIPR): Beta cells, adipose. Co-activation with GLP-1R produces synergistic effects.
Glucagon receptor (GCGR): Hepatocytes, adipocytes. Raises energy expenditure and hepatic fatty acid oxidation; also raises hepatic glucose output.
Amylin receptor complex (AMY1/2/3): Formed by calcitonin receptor + RAMP1/2/3. Central satiety, gastric emptying, glucagon suppression.

Different multi-agonist peptides engage different combinations of these receptors. The specific combination determines the pharmacological profile.

Mono-agonists (reference class)

Semaglutide. GLP-1R only. The reference standard for weight-loss efficacy from mono-agonists.
Liraglutide. GLP-1R only. Predecessor with shorter half-life.
Dulaglutide. GLP-1R only. Different scaffold.
Cagrilintide. Amylin receptors + calcitonin receptor. Non-selective amylin analog. See our cagrilintide overview.

Dual agonists

Tirzepatide (LY3298176).

Receptors: GLP-1R + GIPR
Status: Approved for T2D and obesity
Notes: The first dual incretin agonist to reach market. Substantially greater weight-loss effect than GLP-1 mono-agonists. See our tirzepatide mechanism deep dive.

Survodutide (BI 456906).

Receptors: GLP-1R + GCGR
Status: Phase 3
Notes: The GLP-1/glucagon dual agonist path. Different tradeoff space from tirzepatide — the glucagon receptor component contributes to energy expenditure. See our survodutide overview.

Mazdutide (LY3305677).

Receptors: GLP-1R + GCGR
Status: Phase 3 (primarily in China)
Notes: Different scaffold from survodutide but similar receptor combination. Regional development focus. See our mazdutide overview.

Triple agonists

Retatrutide (LY3437943).

Receptors: GLP-1R + GIPR + GCGR
Status: Phase 3 (TRIUMPH program)
Notes: The first triple agonist to advance to phase 3. Phase 2 weight-loss data showed the largest reductions reported for any incretin-class agent. See our retatrutide vs tirzepatide comparison and retatrutide vs semaglutide research comparison.

Combination therapy

CagriSema (semaglutide + cagrilintide).

Receptors: GLP-1R + amylin receptors + calcitonin receptor
Status: Phase 3 (REDEFINE program)
Notes: Not a single-molecule multi-agonist but a fixed-ratio combination. Distinct pharmacological approach — hits a receptor combination that no single-molecule agent yet targets.

Single-molecule GLP-1/amylin

Amycretin.

Receptors: GLP-1R + amylin receptors (both in one molecule)
Status: Phase 1/2
Notes: The single-molecule alternative to CagriSema. Interesting comparison point for whether the combination approach or the single-molecule approach produces better long-term outcomes.

What the landscape suggests

A few patterns emerge from the current field:

Multi-receptor agonism is the dominant paradigm. No major pharmaceutical program in this space is currently developing a new mono-agonist as a lead candidate. Every next-generation candidate hits at least two receptors.

Different receptor combinations produce different tradeoffs. GLP-1/GIP (tirzepatide) emphasizes glucose management and appetite suppression. GLP-1/glucagon (survodutide, mazdutide) emphasizes energy expenditure. GLP-1/GIP/glucagon (retatrutide) attempts the broadest engagement. GLP-1/amylin (CagriSema, amycretin) engages a distinct pathway that adds to the incretin axis.

The single-molecule vs combination question is unresolved. Is it better to formulate two molecules together (CagriSema) or engineer a single molecule that hits both receptors (amycretin)? This is one of the more interesting open questions for the field.

Half-life engineering has converged. Every major candidate uses either an albumin-binding fatty acid side chain (semaglutide, tirzepatide, retatrutide, cagrilintide) or a similar strategy. Once-weekly dosing is the accepted standard.

What’s not on this list

A few notable adjacencies that are not tri-/dual-agonist peptides but are part of the same research conversation:

GLP-1 receptor partial agonists — a different pharmacological strategy that engages the same receptor with different signaling bias.
PYY analogs — another gut peptide with satiety effects, occasionally combined with GLP-1 agonists in research.
Amylin-only monotherapy (pramlintide, cagrilintide monotherapy) — earlier or ongoing but not the main leading edge.

Research and analytical considerations

For research use of any of these peptides, the same analytical framework applies: mass verification by MS, HPLC purity, water content, and endotoxin, at minimum. Our COA guides (tirzepatide, semaglutide) walk through what a legitimate lab report looks like for the specific molecular masses and impurity profiles of each peptide.

Storage guidance follows the general framework: lyophilized at -20°C or below, reconstituted at 2-8°C for short-term work, aliquoted and frozen for longer storage. The storage temperature post covers the underlying degradation chemistry.