Best Peptides for Weight Loss
GLP-1 agonists and metabolic peptides studied for weight management and fat loss
Weight loss peptides — particularly GLP-1 receptor agonists like Semaglutide and Tirzepatide — have become the most commercially significant peptide class in recent years. These compounds work by mimicking incretin hormones that regulate appetite, blood sugar, and metabolic rate.
The metabolic peptides listed below range from FDA-approved medications to experimental research compounds. We present the evidence objectively: what the clinical trials actually show, what the dosing protocols look like, and what side effects have been documented.
Weight Loss Peptides (11)
Retatrutide
Retatrutide is an investigational medication that activates three hormone receptors (GIP, GLP-1, and glucagon) at the same time. Phase 2 trials showed up to 24% body weight loss at 48 weeks, and it is currently in Phase 3 development.
Semaglutide
Semaglutide is a medication that mimics a natural fullness hormone (GLP-1) in the body. It is FDA-approved as Wegovy for weight management and Ozempic for type 2 diabetes, with significant effects on appetite control and blood sugar regulation.
Tirzepatide
Tirzepatide is a dual-action medication that activates both GIP and GLP-1 receptors, two key fullness and blood sugar hormones. It is FDA-approved as Mounjaro for type 2 diabetes and Zepbound for weight management, outperforming semaglutide in head-to-head trials.
Liraglutide
Liraglutide is a medication that mimics a natural fullness hormone (GLP-1) in the body. It is FDA-approved as Victoza for type 2 diabetes and Saxenda for weight management, with an extensive record of clinical safety and effectiveness data.
Cagrilintide
Cagrilintide is a long-acting amylin analogue, a once-weekly injection that mimics a natural fullness hormone to curb appetite and reduce body weight. It is studied both on its own and combined with semaglutide as CagriSema, which produced about 20 percent weight loss in late-stage trials. It is investigational and not yet approved.
5-Amino-1MQ
5-Amino-1MQ is a small molecule that blocks an enzyme linked to fat storage and metabolic problems. Research focuses on fat cell metabolism, weight loss, and reversing diet-related obesity in animal studies.
Setmelanotide
Setmelanotide (brand name Imcivree) is an FDA-approved injectable peptide that switches on a brain receptor controlling hunger. It is approved specifically for rare forms of severe obesity driven by the brain hunger pathway, not for general weight loss, and in trials it cut both hunger and body weight in those conditions.
Tesofensine
Tesofensine is an oral weight-loss compound that blocks the brain from reabsorbing three appetite-related chemical messengers, noradrenaline, dopamine, and serotonin, so the feeling of fullness lasts longer and hunger drops. In a Phase 2 trial it produced about twice the weight loss of the diet drugs available at the time. It is investigational and not approved.
HGH Fragment 176-191
HGH Fragment 176-191 is a stabilized piece of human growth hormone (amino acids 176-191) and the parent compound of AOD-9604. Research focuses on fat breakdown without the growth-promoting or blood sugar effects of full growth hormone.
AOD-9604
AOD-9604 is a modified fragment of human growth hormone (amino acids 176-191). Originally developed as an anti-obesity compound, it shows preclinical evidence for promoting fat metabolism without affecting blood sugar or growth.
SLU-PP-332
SLU-PP-332 is a synthetic "exercise mimetic", a small molecule that switches on the same cell machinery (mitochondria and fat burning) the body normally activates during aerobic exercise. In animal studies it reduced fat and boosted endurance, but it has not been tested in humans and is poorly absorbed when taken by mouth.