Current and Emerging Anti-Obesity Drugs Including GLP-1 Agonists, Leptin Analogs, and MC4R Agonists | Research

The takeaway

A comprehensive review of anti-obesity medications covers GLP-1 receptor agonists for general obesity alongside emerging peptide-based therapies like leptin analogs and melanocortin-4 receptor agonists that target genetic forms of obesity.

Leptin analogs and MC4R agonists target genetic obesity
These emerging peptide therapies address conditions like lipodystrophy, Bardet-Biedl syndrome, and POMC deficiency where conventional treatments fail

What the researchers found

The review establishes two main categories of peptide-based anti-obesity therapies:

1. GLP-1 receptor agonists work by stimulating satiety hormone secretion and are effective for obesity driven by excessive calorie intake. These are now among the most successful obesity treatments.

2. Emerging genetic-targeted therapies address specific molecular defects: leptin analogs restore function in generalized lipodystrophy and related conditions, while melanocortin-4 receptor (MC4R) agonists target defects in the MC4R signaling pathway that regulates energy balance and appetite. These therapies fill a gap where conventional weight loss strategies fail — genetic obesity conditions like Bardet-Biedl syndrome and POMC deficiency.

Why it matters

Obesity affects over a third of US adults and is a leading cause of preventable death. While GLP-1 drugs have revolutionized treatment for common obesity, patients with genetic forms of obesity have had limited options. The emergence of targeted peptide therapies like leptin analogs (metreleptin) and MC4R agonists (setmelanotide) represents a shift toward precision medicine in obesity — matching the right drug to the right patient based on their underlying biology.

How the study worked

Comprehensive narrative review of anti-obesity medications covering clinical trial data, efficacy, FDA-approved indications, contraindications, and serious side effects. Drug classes reviewed include lipase inhibitors, GLP-1 receptor agonists, leptin analogs, and MC4R agonists.

What this study cannot tell us

Published in Cureus (a community-driven journal), which may have less rigorous peer review than top-tier journals. The review may not capture the latest developments, particularly around tirzepatide and newer pipeline drugs. The coverage of emerging therapies is necessarily based on limited clinical trial data. Head-to-head comparisons between drug classes were not available for all agents discussed.

How to read the evidence

This is a narrative review summarizing clinical trial data and FDA approvals for multiple drug classes. The evidence quality varies by drug — GLP-1 agonists have extensive phase 3 trial data, while newer agents like MC4R agonists have more limited evidence from smaller trials in rare disease populations.

When this study was published

Published in 2023, this review covers the obesity drug landscape at a key inflection point. Some developments since publication (e.g., tirzepatide obesity approval, newer pipeline compounds) are not captured.

The bigger picture

This review captures a pivotal moment in obesity pharmacotherapy: the transition from one-size-fits-all approaches to targeted therapies based on underlying biology. The peptide-based drug classes discussed — GLP-1 agonists, leptin analogs, and MC4R agonists — represent the leading edge of this shift. As genetic testing becomes more accessible and new multi-target peptide drugs enter development, the ability to match patients with the most effective peptide-based therapy will increasingly define obesity treatment.

Questions still open

Could combination approaches using multiple peptide-based drugs (e.g., GLP-1 agonist + MC4R agonist) provide even greater weight loss?
How should genetic testing be integrated into obesity treatment decisions to identify patients who need targeted therapies?
What is the long-term safety profile of newer agents like setmelanotide and metreleptin?

Common questions

What are the main types of peptide-based obesity drugs?

Three main types are covered: (1) GLP-1 receptor agonists (like semaglutide and liraglutide) that reduce appetite by mimicking a natural gut hormone, (2) leptin analogs (like metreleptin) that replace the missing or deficient leptin hormone in certain genetic conditions, and (3) melanocortin-4 receptor agonists (like setmelanotide) that activate brain pathways controlling energy balance in patients with specific gene mutations.

Who needs genetic-targeted obesity drugs instead of GLP-1 agonists?

People with rare genetic obesity conditions — such as generalized lipodystrophy, Bardet-Biedl syndrome, or POMC deficiency — have molecular defects that prevent normal appetite regulation. Standard treatments including GLP-1 agonists may not work well for them because the underlying problem is different. Leptin analogs and MC4R agonists directly address these specific molecular defects, offering targeted treatment for these populations.

Read the original research

Advances in Anti-obesity Pharmacotherapy: Current Treatments, Emerging Therapies, and Challenges.

Cureus, 15(10), e46623

View on PubMed ↗Publisher’s paper ↗

Citation

Brandfon, Skyler; Eylon, Adi; Khanna, Deepesh; Parmar, Mayur S. (2023). Advances in Anti-obesity Pharmacotherapy: Current Treatments, Emerging Therapies, and Challenges.. Cureus, 15(10), e46623. https://doi.org/10.7759/cureus.46623