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Dr Ruchira Karunadasa
Authored on 7 May 2026 by Dr Ruch Karunadasa,Medically reviewed 11 May 2026 by Adeel Arshad.Next review due: 11 May 2027

Understanding GLP-1 and GIP: a guide to dual-action weight loss treatments

Interest in incretin-based medicines for obesity and type 2 diabetes has grown rapidly in the UK. Dual-pathway therapies that target both GLP-1 and GIP receptors sit alongside better-known GLP-1-focused options; all require a prescription, licensing-appropriate use, and ongoing clinical oversight.

Tirzepatide is a dual GIP and GLP-1 receptor agonist, whereas medicines such as semaglutide primarily activate GLP-1 receptors. For how options compare in practice, see Mounjaro vs Wegovy and our weight loss treatments overview.

Illustration explaining GLP-1 and GIP pathways in weight management

What is GLP-1?

GLP-1 (glucagon-like peptide-1) is a hormone involved in appetite regulation and insulin secretion. GLP-1 receptor agonists used in obesity care aim to reduce hunger and improve satiety signalling for many patients, alongside diet and physical activity, when a UK-registered prescriber selects them.


What is GIP?

GIP (glucose-dependent insulinotropic polypeptide) is another incretin-related hormone with roles in nutrient handling and energy metabolism. Targeting GIP as well as GLP-1 is the distinguishing idea behind dual agonists such as tirzepatide; mechanisms are complex and individual responses vary.


Introducing Mounjaro: a dual-action approach

Mounjaro (tirzepatide) activates both GIP and GLP-1 receptors. In clinical development programmes, dual agonism has been associated with substantial mean weight loss in selected populations when combined with lifestyle support; cardiovascular and metabolic benefits remain areas of active study and product-specific safety information.

These medicines are not interchangeable with other brands or indications; always use the product and dose your clinician has prescribed.


What is best? GLP-1 alone vs GLP-1/GIP combination

There is no single trial that answers “best for everyone.” Indirect comparisons across different study designs can be misleading. Programme data have reported, for example, higher mean weight loss at 72 weeks with a GIP/GLP-1 regimen than with some GLP-1-only arms at different time points—context, population, and rescue/adherence rules all matter.

The right choice depends on individual eligibility, tolerability, comorbidities, preferences, and access—not on averages alone. At PrivateDoc, any prescription weight-management plan follows our online assessment, which a UK-registered prescriber reviews before confirming whether treatment is suitable and safe for you.

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Did you know?

Over 40% of the population has tried to lose weight at some point in the last 5 years – so you're certainly not alone