Weight Loss Peptides
29GLP-1 receptor agonists like Semaglutide and Tirzepatide have transformed obesity research, with newer triple agonists like Retatrutide showing even greater potential. This category covers every peptide studied for appetite regulation, fat metabolism, and weight management — from FDA-approved medications to experimental compounds.
5-Amino-1MQ
A pill that aims to switch fat cells from 'storage mode' to 'burning mode' by blocking an enzyme (NNMT) that is overactive in the fat tissue of overweight people. Not technically a peptide, but commonly sold alongside them. Unlike appetite suppressants, this targets the fat cells directly rather than making you eat less. The science is promising in lab studies, but there are no completed human trials yet.
Adipotide
An extreme experimental approach to fat loss — it physically destroys the blood vessels that feed fat tissue, starving fat cells until they die. Originally developed using anti-cancer technology at MD Anderson Cancer Center. While it did reduce fat in monkey studies, it also caused serious kidney damage, which has effectively stopped its development. Not available for human use.
Amycretin
Novo Nordisk's next-generation weight loss drug — the first single molecule that combines two appetite hormones (GLP-1 and amylin) in one shot. The same effect that CagriSema needs two drugs to achieve, amycretin does on its own. In Phase 1b/2a trials, people lost up to 22% of their body weight in 36 weeks, and a once-daily oral pill version is being developed alongside the weekly injection. Phase 3 trials began in 2026. Also known as zenagamtide.
AOD-9604
A small piece of human growth hormone (amino acids 176-191) designed to keep only the fat-burning effects while removing the unwanted side effects of full growth hormone (like swelling and blood sugar problems). The idea is promising — burn fat without the downsides — but it failed to show significant weight loss in clinical trials. Still widely used in research and wellness clinics despite the weak clinical evidence.
AT7687
A novel obesity drug from Danish biotech Antag Therapeutics that takes a completely different approach — instead of suppressing appetite like all the GLP-1 drugs, it stops fat from being stored in the first place by blocking the GIP receptor in fat cells. First-in-human Phase 1 trial completed in 2026 showed it is well tolerated, with mild GI side effects, and produced reductions in LDL cholesterol and resting heart rate alongside weight loss signals.
Cagrilintide
A long-acting version of amylin, a natural hormone your body releases after eating that tells your brain you're full. It works through a completely different pathway than GLP-1 drugs like semaglutide, which is why combining them (as CagriSema) produces even better results. On its own, it reduces how much you eat per meal by signalling fullness earlier. Developed by Novo Nordisk, mainly as part of the CagriSema combination.
CagriSema
A once-weekly injection that combines two powerful appetite-suppressing drugs — cagrilintide and semaglutide — into a single shot. By targeting two different hunger pathways in the brain simultaneously, it achieves roughly 25% body weight loss in trials, making it one of the most effective weight loss treatments ever developed. Think of it as the next generation beyond Wegovy. Still awaiting FDA approval.
CT-388
Roche's once-weekly weight loss injection that targets the same two appetite hormones as tirzepatide (GLP-1 and GIP). Originally developed by Carmot Therapeutics before Roche acquired the company in 2024 specifically to obtain this molecule. In a Phase 2 trial of 469 people, it produced up to 22.5% placebo-adjusted body weight loss at 48 weeks — competitive with tirzepatide and showing no sign of plateau at the highest dose. Phase 3 trials started in 2026.
Danuglipron
Pfizer's once-failed attempt at an oral GLP-1 weight loss pill (code name PF-06882961). Despite producing meaningful weight loss in Phase 2 trials, Pfizer discontinued development in 2025 after reports of potential liver injury in a healthy volunteer. Included here because it remains heavily searched as the cautionary tale of the oral GLP-1 race — and because Pfizer is now developing alternative oral GLP-1 candidates after the danuglipron setback.
Ecnoglutide
A long-acting weekly GLP-1 weight loss injection from Chinese biotech Sciwind Biosciences. Uses a special protein-extension technology to last longer in the body than semaglutide. Late-stage Phase 3 trials in China showed body weight loss of 14-15% in obesity and good blood-sugar control in type 2 diabetes. Approval in China is expected first, with international filings to follow. One of several Chinese-developed GLP-1s reaching the global market.
GLP-1
The natural appetite hormone that your gut produces after eating — it's what all GLP-1 weight loss drugs (semaglutide, tirzepatide, etc.) are designed to copy. Your body makes it naturally, but it breaks down within 1-2 minutes, which is far too fast to use as a medicine. That's why drug companies created modified versions that last days instead of minutes. Included here because understanding GLP-1 is key to understanding the entire class of modern weight loss drugs.
HGH Fragment 176-191
The original, unmodified version of the growth hormone fat-burning fragment — essentially the same concept as AOD-9604 but less stable and shorter-lasting. Contains the part of growth hormone responsible for fat metabolism without the parts that cause growth or blood sugar issues. Requires more frequent dosing than AOD-9604, and has even less clinical evidence supporting its effectiveness.
L-Carnitine
A natural substance your body already makes that acts as a 'shuttle' to carry fat into your cells' energy factories (mitochondria) where it gets burned for fuel. Without enough carnitine, your body literally cannot burn long-chain fats for energy. One of the most popular and well-studied fat metabolism supplements available. Has FDA-approved forms for people with carnitine deficiency, and is widely available over the counter as a supplement.
Lemon Bottle
A cosmetic fat-dissolving injection from South Korea that is injected directly into stubborn fat areas (like a double chin or love handles) to break down fat cells locally. Contains vitamin B2, lecithin (a natural fat emulsifier), and bromelain (a pineapple enzyme). This is not a weight loss treatment — it's a targeted body contouring procedure, similar to CoolSculpting but using injections instead of cold. Requires multiple sessions.
Lipo-C
A vitamin and amino acid injection commonly offered at weight loss clinics to support fat metabolism. Contains a mix of nutrients (methionine, inositol, choline, B vitamins, and L-carnitine) that help your liver process and export fat, and help your cells burn fat for energy. Think of it as a metabolic support shot — it's not a standalone weight loss treatment, but is used alongside diet and exercise to help your body process fat more efficiently.
Liraglutide
A GLP-1 medication that mimics a natural gut hormone (97% similar to native GLP-1) and is the predecessor to semaglutide. FDA-approved for both type 2 diabetes (Victoza) and obesity (Saxenda). One of the most prescribed weight loss medications worldwide, with extensive long-term safety data including reduced risk of heart attack and stroke in diabetic patients.
MariTide
Amgen's monthly weight loss injection — and the only one in late-stage development you only have to take every four weeks rather than every week. Unusually, it activates GLP-1 but blocks GIP (most other dual drugs activate both). In Phase 2 it produced around 20% body weight loss at 52 weeks, with the added benefit of slow weight regain after stopping treatment in animal studies. Phase 3 MARITIME trials started in 2026. Generic name maridebart cafraglutide.
Mazdutide
A weight loss injection that suppresses appetite while also boosting your metabolism and helping your liver burn fat. Approved in China for obesity in 2024, with up to 14% body weight loss in trials. It targets two hormones — GLP-1 (which reduces hunger) and glucagon (which increases calorie burning and liver fat breakdown). Particularly promising for people with fatty liver disease alongside obesity.
NN1706
Novo Nordisk's answer to retatrutide — a once-daily injection that activates all three of the major appetite and metabolism hormones (GLP-1, GIP, and glucagon). The first human data was published in 2026, showing meaningful weight loss in obese subjects and confirming the daily-dosing mechanism is tolerable. Direct competitor to Lilly's once-weekly retatrutide, with the trade-off of more frequent dosing in exchange for potentially smoother side-effect control and easier dose adjustment.
Orforglipron
The first weight loss drug in the GLP-1 class that comes as a daily pill rather than a weekly injection — and unlike Rybelsus, you can take it with food and water. Made by Eli Lilly, it is technically a small molecule rather than a peptide, but it activates the same GLP-1 receptor as semaglutide and tirzepatide. Phase 3 trials in 2026 (ACHIEVE-1 in diabetes, ATTAIN-1 and ATTAIN-2 in obesity) have shown around 14-15% body weight loss. Likely to be the first oral GLP-1 to compete on weight loss with the injectables.
Pemvidutide
A weekly weight loss injection from Altimmune that targets two hormones (GLP-1 for appetite, glucagon for fat-burning) — similar to mazdutide and survodutide. Particularly being developed for fatty liver disease (MASH) alongside obesity. Phase 2b results showed around 15.6% body weight loss at 48 weeks, with significant reductions in liver fat. Also branded as ALT-801. Now in Phase 3 trials for both indications.
Retatrutide
The first weight loss drug to target three appetite and metabolism hormones at once (GIP, GLP-1, and glucagon). In early trials, people lost up to 24% of their body weight — the highest ever recorded for any weight loss medication. The third hormone target (glucagon) helps burn more calories and reduce liver fat, going beyond what current drugs like semaglutide or tirzepatide can achieve. Still in clinical trials.
Semaglutide
The most widely prescribed weight loss medication in the world, sold as Wegovy and Ozempic. Works by dramatically reducing appetite and food cravings — most people report feeling full much faster and losing interest in snacking. In clinical trials, patients lost an average of 15-17% of their body weight. Also available as a daily pill (Rybelsus). Originally developed for type 2 diabetes, it also helps control blood sugar levels.
Survodutide
A weight loss injection being developed specifically for both obesity and fatty liver disease (MASH). It reduces appetite through one pathway while simultaneously telling your liver to burn its stored fat through another. This dual approach tackles the root cause (eating too much) and the downstream damage (fat build-up in the liver) at the same time. Still in clinical trials.
Tesamorelin
The only growth hormone peptide with active FDA approval — sold as Egrifta for reducing dangerous belly fat (visceral fat) in HIV patients. It's especially effective at targeting the deep fat around your organs, which is the most harmful type. Widely used off-label by people wanting to improve body composition, reduce belly fat, and address fatty liver. In trials it reduced trunk fat by 15-18%.
Tesamorelin + Ipamorelin
A popular combination pairing Tesamorelin (FDA-approved for certain conditions) with Ipamorelin to boost growth hormone. Favored for improving body composition, reducing belly fat, and anti-aging. Tesamorelin has proven effectiveness for visceral fat reduction, and Ipamorelin has a clean side-effect profile, making this a premium GH peptide protocol.
Tesofensine
A medication that blocks reuptake of serotonin, dopamine, and norepinephrine — originally developed for Alzheimer's and Parkinson's but showed significant weight loss in clinical trials. Reduces appetite through brain signaling in appetite centers. A different approach than GLP-1 medications and other peptide-based weight loss treatments.
Tirzepatide
Sold as Mounjaro and Zepbound, this is one of the most effective weight loss medications available. It works by targeting two appetite hormones at once (GIP and GLP-1), making it more powerful than medications like semaglutide that only target one. People in clinical trials lost up to 22.5% of their body weight. Also FDA-approved for type 2 diabetes, and improves cholesterol and blood fat levels.
VK2735
Viking Therapeutics' once-weekly weight loss injection that, like tirzepatide, hits both the GLP-1 and GIP receptors. In a 13-week Phase 2 trial it produced 14.7% mean body weight loss — the steepest early loss curve recorded for any obesity drug — and Phase 3 VANQUISH trials began in 2026. An oral tablet version is also in earlier development. Viking is one of the only small biotech companies competing directly with Lilly and Novo Nordisk in the GLP-1 space.