Peptides for Fat Loss: A Weight Management Research Guide
Weight management peptides span a range of mechanisms — from targeted lipolysis signals to complex multi-receptor hormonal systems. Understanding the mechanistic differences between peptide classes helps contextualize their clinical efficacy data and research applications. This guide covers the key compounds from AOD-9604 to the triple GLP agonists.
AOD-9604: targeted lipolysis
AOD-9604 (Advanced Obesity Drug 9604) is a synthetic fragment of human growth hormone — specifically the amino acid sequence 176–191 from the C-terminal end of hGH. This fragment was identified as the region of the hGH molecule responsible for its lipolytic (fat-burning) effects, without the growth-promoting or insulin-sensitizing effects of full hGH. AOD-9604 stimulates lipolysis through beta-3 adrenergic receptor activation and inhibits lipogenesis (new fat synthesis), with no significant effect on blood glucose, insulin sensitivity, or IGF-1 levels. This selectivity makes it relevant for research focused specifically on body fat reduction without the broader hormonal effects of exogenous hGH. Research protocol: 500mcg–1mg subcutaneous, 5 days on/2 days off, administered fasted before cardio or sleep.
GLP-1: the foundational receptor agonist
GLP-1 receptor agonism was covered in depth in a previous Journal article — see GLP-1 vs GLP-1 Dual Agonist vs GLP-3 for the full mechanistic comparison. In summary: GLP-1 receptor agonism enhances insulin secretion, suppresses glucagon, slows gastric emptying, and critically, signals satiety to the hypothalamus. The brain-mediated appetite suppression is the primary weight loss driver, producing approximately 15% mean body weight reduction in Phase 3 trials with semaglutide. See the GLP-1 research profile for dosing specifications.
GLP-1 Dual Agonist: adding GIP
Adding GIP receptor co-agonism to GLP-1 agonism produces synergistic rather than additive weight loss effects, because the two receptor pathways converge on overlapping intracellular signaling machinery. The dual mechanism also improves gastrointestinal tolerability compared to GLP-1 mono-agonism, which has significant implications for research adherence. Phase 3 data with tirzepatide (15mg) demonstrated 20.9% mean weight reduction over 72 weeks — approximately 6 percentage points greater than the leading GLP-1 mono-agonist.
GLP-3 triple agonism: adding glucagon
Triple GLP-1/GIP/glucagon agonism adds energy expenditure to the appetite suppression and insulin sensitization of dual agonism. Glucagon receptor activation increases resting metabolic rate and hepatic fat oxidation — adding a metabolic rate component to the weight loss equation. Phase 3 TRIUMPH-4 data showed up to 26.3% mean weight reduction at 48 weeks, with participants still losing weight at trial end. See the GLP-3 entry in the database.
Survodutide: GLP-1 plus glucagon for metabolic liver disease
Survodutide is a GLP-1/glucagon dual agonist — distinct from the GLP-1/GIP dual agonist class. The glucagon receptor activation in Survodutide is particularly relevant for hepatic fat metabolism, making it the most studied compound in the metabolic liver disease (NAFLD/MASH) research space among the new generation of weight management peptides. Phase 3 data pending. Weekly dosing. See the Survodutide entry in the database.
Cagrilintide: the amylin analogue
Cagrilintide is a long-acting amylin analogue — distinct from the GLP class entirely. Amylin is co-secreted with insulin from pancreatic beta cells and reduces food intake, slows gastric emptying, and suppresses glucagon through amylin receptor binding in the hypothalamus and brainstem. CagriSema — the combination of cagrilintide with semaglutide — produced 20.4% weight loss in the REDEFINE-1 Phase 3 trial, with an NDA submitted to the FDA in December 2025. The key research value of cagrilintide in stacks is its ability to allow GLP-1 dose reduction while maintaining or enhancing weight loss outcomes — reducing dose-dependent GI adverse effects. Weekly dosing. See the database for full entry.