Journal September 25, 2026 4 min read

Which peptides are studied in relation to intermittent fasting?

A research-supply overview of the peptides and peptide-adjacent compounds examined alongside intermittent fasting protocols, including GLP-1 receptor agonists, LL-37, leptin, and gut-endocrine signals.

peptides-pro Editorial

Intermittent fasting (IF) is a dietary pattern that cycles between periods of eating and fasting. In the research literature, the peptides most often studied in relation to IF are glucagon-like peptide-1 (GLP-1) receptor agonists, the antimicrobial peptide LL-37, leptin and its receptor (LepRb), and gut-derived endocrine peptides. These are not a single class; they include an incretin mimetic, a cathelicidin, an adipokine, and enteroendocrine hormones. The evidence block does not provide sequence, formula, or molecular weight for these compounds, so those identifiers are not reported here.

The work centres on the GLP-1 receptor family and on hypothalamic leptin receptor signalling, with additional study of gut-endocrine axis peptides and salivary inflammatory peptides.

Research Studies

GLP-1 receptor agonists and time-restricted eating in prostate cancer patients on androgen deprivation therapy

A phase II trial compares time-restricted eating (TRE) and GLP-1 receptor agonists (semaglutide and tirzepatide) against an American Heart Association heart-healthy diet in prostate cancer patients undergoing androgen deprivation therapy (ADT). The trial examines cardiovascular and metabolic outcomes in this population, which is at increased risk of cardiovascular disease due to treatment-related metabolic changes [4].

LL-37 and salivary inflammatory biomarkers with keto diet and intermittent fasting

A study investigates the impact of short-term keto diet and intermittent fasting on oral health and salivary inflammatory biomarkers, including C-reactive protein, IL-6, TNF-alpha, and LL-37 peptide, as well as salivary flow and pH. The study population is described as the Iraqi population [8].

Leptin sensitivity and JMJD3-dependent epigenetic regulation in the hypothalamus

Preclinical work reports that alternate-day fasting enhances leptin sensitivity via JMJD3-dependent epigenetic regulation of the leptin receptor in the hypothalamus. Leptin resistance is characterised by diminished responsiveness to leptin and disrupted energy homeostasis, with transcriptional repression of LepRb impairing downstream signal transduction [9]. This finding is from an animal model.

Gut-endocrine axis responses to Senna alexandrina supplementation in obese rats

In obese rats, intermittent fasting amplified gut-endocrine axis responses to Senna alexandrina supplementation. The animals were fed a high-fat, high-sucrose diet, which disrupted lipid metabolism, glucose homeostasis, and gut microbial balance [10]. This is an animal-only finding.

Mitophagy and mitochondrial DNA dynamics during Ramadan dry fasting versus 16:8 time-restricted feeding

A study investigates how different fasting types affect mitochondrial clearance and renewal. Ramadan dry fasting involves total restriction of food and fluids from dawn to sunset, while standard 16:8 intermittent fasting permits water. The study measures blood markers related to mitochondrial DNA and metabolic health over 30 days [2].

Metabolic phenotyping and personalised protocols in type 2 diabetes

A study tests the Snouda Metabolic Score (SMS) to classify type 2 diabetes patients into metabolic phenotypes across five systems: insulin resistance, chronic inflammation, hormonal disruption, gut microbiome imbalance, and mitochondrial dysfunction. Participants then follow a personalised 24-week lifestyle and nutritional protocol targeting their phenotype [3].

Probiotic intervention and weight regain in weight cyclers

A study evaluates the potential of probiotics in obesity management, specifically their impact on weight regain after caloric restriction. Gut microbiota are described as playing a critical role in weight management, and probiotics may reduce weight regain by modulating appetite and metabolism [5].

Intermittent fasting versus frequent feeding in obese women

A 12-week study compared 16:8 time-restricted feeding plus home-based exercise with a calorie-restricted standard diet plus home-based exercise in obese women. Outcomes included body composition, lipid profile, glycemic control, and liver function enzyme levels [6].

Wearable monitoring of intermittent fasting in an N-of-1 study

A prospective N-of-1 study investigates the effects of a human optimisation programme on metabolic health and overall well-being, examining correlations between continuous glucose monitoring and other measures. The study notes that intermittent fasting may reduce systemic inflammation and help prevent chronic diseases, and that IF research can help athletes sustain performance during fasting periods [7].

Intermittent fasting for pancreatitis

A clinical trial compares intermittent fasting with a standard diet approach for improving quality of life related to pancreas disease, with the aim of improving symptoms and preventing hospitalisation for pancreas-related issues [1].

If you are reading this for personal health reasons

The compounds discussed here are sold for laboratory research only. We do not provide dosing or medical guidance. Anyone considering a compound for themselves should speak to a licensed clinician.