Peptides for Weight Loss

The most widely prescribed GLP-1 agonist for weight management globally

Available in the UK as Wegovy® (subcutaneous, 2.4mg weekly) for weight management and as Ozempic® (1mg weekly) for type 2 diabetes. NICE-approved for weight management in adults with BMI ≥35 (or ≥30 with comorbidities) through specialist weight management services. The STEP trial programme demonstrated average weight loss of approximately 15% of body weight over 68 weeks. NHS availability is expanding but subject to supply and commissioning arrangements.

Dual GLP-1/GIP receptor agonist with superior weight loss efficacy in trials

Available in the UK as Mounjaro® for type 2 diabetes (NICE-approved 2024). Weight management indication (Zepbound®) is anticipated for UK approval. The SURMOUNT-1 trial demonstrated up to 22.5% body weight reduction at the highest dose — the greatest weight loss achieved by any single peptide agent in clinical trials. Dual incretin agonism provides complementary metabolic benefits beyond GLP-1 alone.

First-generation daily GLP-1 agonist approved for weight management

Available as Saxenda® (3mg daily injection) for weight management in the UK. NICE-approved for adults with BMI ≥35 (or ≥30 with comorbidities) for up to 2 years. Requires daily injection (vs weekly for semaglutide). The SCALE trial showed approximately 8% body weight loss. Largely superseded by semaglutide in clinical preference but remains an option where semaglutide is unsuitable or unavailable.

Triple GLP-1/GIP/glucagon receptor agonist in late-stage clinical trials

Phase 3 trials are underway following remarkable Phase 2 results showing up to 24% body weight reduction over 48 weeks. The addition of glucagon receptor agonism to dual incretin activity may enhance energy expenditure and hepatic fat reduction. Not yet approved in any jurisdiction. Represents the next frontier in peptide-based weight management, with potential UK availability dependent on trial outcomes and MHRA review.

Dual GLP-1/glucagon receptor agonist with metabolic benefits

In Phase 3 clinical development for obesity and MASH (metabolic dysfunction-associated steatohepatitis). Phase 2 data demonstrated approximately 19% weight loss alongside significant reductions in liver fat. The glucagon component may provide metabolic advantages including enhanced energy expenditure. Not yet approved; UK availability dependent on successful trials and MHRA approval.

Long-acting amylin analogue being developed in combination with semaglutide

Being studied in combination with semaglutide (CagriSema) for enhanced weight loss beyond semaglutide alone. Amylin is a pancreatic peptide that promotes satiety and slows gastric emptying through mechanisms complementary to GLP-1. Phase 3 REDEFINE trial programme is ongoing. The combination aims to address the efficacy plateau seen with GLP-1 monotherapy. Not yet approved.

Modified growth hormone fragment researched for fat metabolism

A modified fragment of human growth hormone (amino acids 177–191) researched for its effects on fat metabolism without the broader hormonal effects of full-length GH. Early research suggested lipolytic properties, but clinical trial data have been disappointing and it has not achieved regulatory approval for weight loss. Not available on the NHS. Classified as a research peptide with limited clinical evidence supporting efficacy.

Triple monoamine reuptake inhibitor with central appetite suppression

Originally developed as a neurological drug, tesofensine inhibits reuptake of noradrenaline, dopamine, and serotonin, producing significant appetite suppression and modest increases in metabolic rate. Phase 2 trials showed approximately 12.8% weight loss. Development has been limited by cardiovascular safety concerns (increased heart rate and blood pressure). Not approved in the UK or any major market. Included for completeness but not a peptide in the traditional sense.