⚖️ Category
Peptides for Weight Loss
Peptides researched for appetite regulation, fat metabolism, and blood-glucose control. This category includes some of the only peptides with large, completed human clinical trials and FDA approval.
Peptides researched for appetite regulation, fat metabolism, and blood-glucose control. This category includes some of the only peptides with large, completed human clinical trials and FDA approval.
Weight-loss and metabolic peptides are the most clinically validated group in this encyclopedia. The headline compounds are incretin mimetics — peptides that copy gut hormones (GLP-1, GIP, glucagon, and amylin) the body releases after eating. By acting on appetite centres in the brain, slowing stomach emptying, and improving glucose-dependent insulin release, they reduce hunger and food intake.
This category spans the full arc of the field: from first-generation agents like exenatide and daily liraglutide, through today's once-weekly semaglutide and dual-agonist tirzepatide, to investigational triple agonists like retatrutide. Several are FDA-approved prescription medicines with large randomized trials behind them. Others sold for "fat loss" — such as AOD-9604 and MOTS-c — are unapproved and not supported by convincing human evidence. We flag which is which on every page.
A GLP-1 receptor agonist and one of the most clinically validated peptides in this encyclopedia — FDA-approved for type 2 diabetes and chronic weight management.
Read the guide →A first-in-class dual GIP and GLP-1 receptor agonist that produced some of the largest weight-loss results recorded in obesity trials.
Read the guide →A growth-hormone-releasing hormone (GHRH) analog and FDA-approved drug (Egrifta) for reducing excess abdominal fat in people with HIV-associated lipodystrophy.
Read the guide →A modified fragment of human growth hormone (residues 176–191) developed as an anti-obesity drug — but human trials did not show meaningful weight loss.
Read the guide →A mitochondrial-derived peptide studied as a metabolic regulator and “exercise mimetic,” with effects on insulin sensitivity in animal models.
Read the guide →An investigational “triple agonist” (GIP, GLP-1, and glucagon receptors) that produced some of the largest weight reductions yet seen in obesity trials — with its Phase 3 program now complete and an FDA filing expected in 2027.
Read the guide →A once-daily GLP-1 receptor agonist, FDA-approved for type 2 diabetes (Victoza) and weight management (Saxenda) — an important predecessor to semaglutide.
Read the guide →A long-acting amylin analog studied for weight management, notably in combination with semaglutide (“CagriSema”) — an investigational, non-incretin approach to appetite control.
Read the guide →An investigational dual glucagon and GLP-1 receptor agonist studied for obesity and for metabolic liver disease (MASH/NASH).
Read the guide →An investigational GLP-1 and glucagon receptor dual agonist (an oxyntomodulin analog) studied for obesity and diabetes, with late-stage trials concentrated in China.
Read the guide →An experimental “fat-targeted proapoptotic peptide” designed to kill the blood supply of white fat tissue — dramatic in animal studies but flagged for kidney toxicity.
Read the guide →An MC4-receptor agonist and FDA-approved drug (Imcivree) for chronic weight management in specific rare genetic obesity disorders.
Read the guide →A GLP-1 receptor agonist derived from exendin-4 (originally from Gila monster venom) — one of the first incretin drugs, FDA-approved for type 2 diabetes.
Read the guide →A once-weekly GLP-1 receptor agonist, FDA-approved for type 2 diabetes and shown to reduce cardiovascular events.
Read the guide →A synthetic analog of the hormone amylin, FDA-approved (as Symlin) as a mealtime add-on to insulin for diabetes, with modest appetite and weight effects.
Read the guide →A once-daily, exendin-based GLP-1 receptor agonist, FDA-approved for type 2 diabetes, with a strong focus on lowering post-meal glucose.
Read the guide →A long-acting, exendin-based GLP-1 receptor agonist that reduced cardiovascular and kidney events in a major trial; approved in some countries but not by the FDA.
Read the guide →The body's main counter-regulatory peptide hormone — it raises blood sugar, is FDA-approved as an emergency treatment for severe hypoglycemia, and its receptor is now a deliberate target of newer weight-loss drugs.
Read the guide →An investigational unimolecular GLP-1 and amylin receptor dual agonist studied for obesity, notable for early trials in both oral and injectable forms.
Read the guide →An investigational dual GLP-1 and glucagon receptor agonist studied for obesity and metabolic dysfunction-associated steatohepatitis (MASH).
Read the guide →An investigational long-acting GLP-1 receptor agonist studied for obesity and type 2 diabetes, with development advancing notably in China.
Read the guide →The body's essential blood-sugar-lowering peptide hormone and the original life-saving peptide medicine — produced today as recombinant human insulin and many engineered analogs for diabetes.
Read the guide →A synthetic fragment of the tail end of the growth-hormone molecule, marketed as a fat-loss peptide because it was designed to reproduce GH's effect on fat without its effects on growth or blood sugar — though human evidence is lacking.
Read the guide →An investigational once-weekly injection that combines two peptides — the amylin analog cagrilintide and the GLP-1 drug semaglutide — in a single fixed-dose product, under FDA review as one of the most anticipated next-generation weight-loss treatments.
Read the guide →A long-acting amylin analog being developed by Zealand Pharma and Roche as a once-weekly weight-loss treatment — part of the amylin wave widely seen as the next major class after GLP-1 drugs.
Read the guide →Eli Lilly's investigational selective amylin receptor agonist for obesity, which produced up to about 20% weight loss in a Phase 2 trial and is now in late-stage testing.
Read the guide →Amgen's investigational obesity therapy — a peptide-antibody conjugate given as infrequently as once a month that activates the GLP-1 receptor while blocking the GIP receptor.
Read the guide →Nearly every effective peptide in this category works on the same underlying principle: it imitates a hormone your gut already releases when you eat. These are called incretins, and the body uses them to coordinate the response to a meal — releasing insulin, slowing digestion, and signalling to the brain that food has arrived.
The drugs extend that signal. Natural GLP-1 is broken down within minutes; semaglutide and its relatives are engineered to last days, which converts a brief post-meal signal into a continuous one. The practical effects stack up in three places:
The generational story of this category is the addition of more pathways. Semaglutide engages GLP-1 alone. Tirzepatide adds GIP. Retatrutide adds glucagon on top of both. And the newest frontier steps outside the incretin system entirely, to amylin — a separate satiety hormone released with insulin — which is what CagriSema, petrelintide and eloralintide are built around.
This is the one category on the site where the top tier is genuinely strong, which makes the contrast with the bottom tier especially sharp.
Approved medicines with large randomized trials. Semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide and others have been tested in thousands of people, reviewed by regulators, and in several cases followed for cardiovascular outcomes rather than weight alone. When we say the evidence is good here, it means trials in the tens of thousands, not mechanism plus optimism.
Investigational drugs with real human data. Retatrutide, CagriSema, petrelintide, eloralintide and MariTide have completed randomized trials but are not approved. Their results are real and their long-term profiles are not yet established — and mid-stage results in obesity have failed to hold up at scale before.
Research chemicals with little or no human evidence. Compounds marketed for "fat loss" such as AOD-9604, HGH Fragment 176-191 and MOTS-c sit here. AOD-9604 is the instructive case: it reached human obesity trials and failed to beat placebo. That is not an absence of evidence, it is evidence pointing the wrong way.
The gap between tier one and tier three in this category is as wide as anywhere in medicine, and marketing frequently blurs it by calling both "peptides for weight loss". They are not comparable propositions.
In trials, the dual and triple agonists (tirzepatide and investigational retatrutide) have generally produced the largest average weight loss, followed by semaglutide, with older GLP-1 agonists like liraglutide producing less. Results are highly individual and depend on dose, diet, and activity.
The effective, evidence-backed ones (semaglutide, tirzepatide, liraglutide and similar) are prescription-only medicines used under medical supervision. 'Research chemical' or compounded versions sold outside the pharmacy supply chain are not quality-assured and carry real risks.
They mimic different gut/pancreatic hormones. GLP-1 mainly curbs appetite and improves insulin response; GIP is a second incretin combined with GLP-1 in tirzepatide; glucagon activity (in dual/triple agonists) can raise energy expenditure; and amylin analogs (like cagrilintide) promote fullness through a separate pathway.
The approved incretin drugs have well-characterized safety profiles dominated by gastrointestinal side effects, with specific warnings (e.g. thyroid C-cell tumors in rodents) — which is why they need medical oversight. Unapproved compounds lack this safety data entirely.