LEAP-2: The Newly Discovered Peptide That Blocks Ghrelin and May Fight Obesity
LEAP-2 is a liver-produced peptide that naturally blocks the ghrelin receptor, making it ghrelin's built-in rival in appetite control and a potential new target for obesity treatment.
Quick Facts
What This Study Found
LEAP-2 (liver-expressed antimicrobial peptide 2) is a recently discovered endogenous antagonist of the ghrelin receptor (GHSR1a). It works as a noncompetitive allosteric blocker — meaning it doesn't compete with ghrelin directly but instead changes the receptor's shape to prevent ghrelin from activating it. In lab experiments, LEAP-2 blocked ghrelin's ability to trigger calcium signaling, and in animal studies, it impaired ghrelin's metabolic effects.
The review presents LEAP-2 as ghrelin's natural counterbalance in energy metabolism: where ghrelin drives hunger and promotes fat storage, LEAP-2 opposes these effects. This makes LEAP-2 a promising therapeutic target for obesity and metabolic diseases involving ghrelin system dysregulation.
Key Numbers
LEAP-2 = endogenous GHSR1a antagonist · Noncompetitive allosteric mechanism · Blocks ghrelin-induced Ca²⁺ release in vitro · In vivo metabolic effects confirmed
How They Did This
Narrative review synthesizing recent discoveries about LEAP-2's role as a ghrelin receptor antagonist, covering molecular pharmacology (in vitro receptor studies), in vivo metabolic effects, and therapeutic implications for obesity and metabolic disease.
Why This Research Matters
For over 20 years, ghrelin was the only known hormone that stimulates appetite. The discovery of LEAP-2 as its natural antagonist fundamentally changes our understanding of hunger regulation — it's not just about ghrelin levels, but the balance between ghrelin and LEAP-2. This opens an entirely new therapeutic avenue: rather than blocking ghrelin directly, boosting LEAP-2 could suppress appetite through the body's own counterregulatory system.
The Bigger Picture
The ghrelin system was long thought to be a one-way signal — ghrelin goes up, you get hungry. LEAP-2's discovery adds a counterweight, creating a push-pull system more like insulin/glucagon for blood sugar. This has major implications for obesity research: instead of just suppressing appetite with GLP-1 drugs, future treatments might restore the ghrelin-LEAP-2 balance. It also helps explain why some obese individuals have low ghrelin but still overeat — their LEAP-2 levels may be dysregulated too.
What This Study Doesn't Tell Us
Narrative review without systematic methodology. LEAP-2 research was very early-stage when this was published. Most evidence was from in vitro receptor studies and animal models. Human clinical data on LEAP-2 modulation was absent. The therapeutic potential discussed was largely speculative at time of publication.
Questions This Raises
- ?Can synthetic LEAP-2 or LEAP-2 mimetics reduce food intake and body weight in human clinical trials?
- ?How do LEAP-2 levels change with obesity, weight loss, and bariatric surgery in humans?
- ?Could combining LEAP-2 enhancement with GLP-1 agonists produce additive anti-obesity effects?
Trust & Context
- Key Stat:
- First endogenous ghrelin receptor antagonist discovered LEAP-2 is the body's own built-in ghrelin blocker — a liver-produced peptide that naturally counteracts the hunger hormone, creating a yin-yang balance in appetite control.
- Evidence Grade:
- Rated low-moderate: published in a high-impact pharmacology journal and based on emerging in vitro and in vivo evidence, but the field was very early-stage. No human clinical data was available at time of publication.
- Study Age:
- Published in 2018, shortly after LEAP-2's role as a ghrelin antagonist was first discovered. Subsequent research has significantly expanded our understanding of LEAP-2 in human metabolism, so this should be read as an early-stage overview.
- Original Title:
- Ghrelin and LEAP-2: Rivals in Energy Metabolism.
- Published In:
- Trends in pharmacological sciences, 39(8), 685-694 (2018)
- Authors:
- Al-Massadi, Omar, Müller, Timo, Tschöp, Matthias(4), Diéguez, Carlos, Nogueiras, Ruben
- Database ID:
- RPEP-03565
Evidence Hierarchy
Summarizes existing research without a strict systematic method.
What do these levels mean? →Frequently Asked Questions
What is LEAP-2 and how does it relate to hunger?
LEAP-2 is a peptide made by your liver that naturally blocks the ghrelin receptor — the same receptor that ghrelin activates to make you feel hungry. Think of it as ghrelin's natural opponent: when LEAP-2 is high, ghrelin can't signal as effectively, and appetite is suppressed.
Could LEAP-2 be used as a weight loss drug?
It's a promising idea but still early-stage. If researchers can develop drugs that mimic or boost LEAP-2's effects, they could theoretically suppress appetite by blocking ghrelin signaling. However, no LEAP-2-based drugs have been tested in humans yet.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-03565APA
Al-Massadi, Omar; Müller, Timo; Tschöp, Matthias; Diéguez, Carlos; Nogueiras, Ruben. (2018). Ghrelin and LEAP-2: Rivals in Energy Metabolism.. Trends in pharmacological sciences, 39(8), 685-694. https://doi.org/10.1016/j.tips.2018.06.004
MLA
Al-Massadi, Omar, et al. "Ghrelin and LEAP-2: Rivals in Energy Metabolism.." Trends in pharmacological sciences, 2018. https://doi.org/10.1016/j.tips.2018.06.004
RethinkPeptides
RethinkPeptides Research Database. "Ghrelin and LEAP-2: Rivals in Energy Metabolism." RPEP-03565. Retrieved from https://rethinkpeptides.com/research/al-massadi-2018-ghrelin-and-leap2-rivals
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.