Weight Loss

A GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management, one of the most widely prescribed peptide drugs.

A dual GIP/GLP-1 receptor agonist FDA-approved for diabetes and weight management, producing the largest weight loss seen in clinical trials.

An FDA-approved GHRH analog used to reduce visceral fat in HIV-associated lipodystrophy.

A GLP-1 receptor agonist FDA-approved for diabetes (Victoza) and weight management (Saxenda), the predecessor to semaglutide.

A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes, with proven cardiovascular benefits and moderate weight loss effects.

The endogenous 28-amino-acid 'hunger hormone' from the stomach — the natural ligand of GHS-R1a, the receptor that GHRP-2, GHRP-6, hexarelin, ipamorelin, and MK-677 all target. A research peptide and pharmacology reference, not a self-administered compound.

The 167-amino-acid adipose hormone discovered in 1994 that was supposed to cure obesity — and did, for the handful of people born without it. For everyone else, the story turned out to be leptin resistance, not leptin deficiency, and the therapeutic lesson has been much harder than the biology.

The endogenous 13-amino-acid melanocortin hormone cleaved from POMC. Parent molecule for the melanotan / setmelanotide / KPV cluster — acts at MC1R (pigmentation), MC3R/MC4R (appetite, energy balance), and MC5R, with well-characterized anti-inflammatory activity.

An endogenous gut-and-brain peptide hormone released by intestinal I-cells that triggers gallbladder contraction, pancreatic enzyme secretion, and meal-ending satiety via vagal CCK-1 receptors.

The circulating 'cellular stress' hormone of the TGF-β superfamily — the molecule that links metformin-induced weight loss, pregnancy-associated hyperemesis, and cancer cachexia through a single brainstem receptor (GFRAL). Not a self-administered peptide; the clinical programs are antibodies that block GDF-15, not supply it.

Foundayo (orforglipron) is Eli Lilly's oral small-molecule GLP-1 receptor agonist. Phase 3 trials show up to 11.2% weight loss via daily pill — no injections required. Regulatory submissions expected 2026.

An investigational dual glucagon/GLP-1 receptor agonist from Boehringer Ingelheim and Zealand Pharma. Phase 3 SYNCHRONIZE-1 (April 28, 2026 topline) achieved 16.6% mean weight loss at 76 weeks — the first positive Phase 3 readout in the SYNCHRONIZE obesity program. FDA Fast Track (2021) and Breakthrough Therapy (2024) designations for MASH; full SYNCHRONIZE-1 data at ADA June 2026.

Amgen's first-in-class once-monthly bispecific antibody-peptide conjugate for obesity — GLP-1 receptor agonist + GIP receptor antagonist. Phase 2 NEJM showed up to 21.6% weight loss at 52 weeks with no plateau.

An investigational triple agonist (GIP/GLP-1/glucagon) from Eli Lilly. Not FDA-approved. Phase III TRIUMPH-4 results showed 23.7% weight loss — the most of any obesity drug in development.

A long-acting amylin analogue being developed in combination with semaglutide (CagriSema) for enhanced weight loss.

Novo Nordisk's investigational unimolecular dual GLP-1 and amylin receptor agonist, advanced in both subcutaneous and oral formulations. Phase 1b/2a SC topline (Lancet 2025) showed up to 24.3% mean weight loss at 36 weeks — among the largest weight-loss signals reported for any single peptide, anywhere. Not approved by any regulator; Phase 2 obesity program underway.

The first GLP-1 receptor agonist, originally derived from Gila monster venom, FDA-approved for type 2 diabetes.

An FDA-approved synthetic analogue of amylin used alongside insulin for diabetes, also studied for weight management.

An FDA-approved MC4R agonist for rare monogenic obesity (POMC/PCSK1/LEPR deficiency, Bardet-Biedl syndrome) and — as of March 2026 — acquired hypothalamic obesity in patients aged 4 and older.

A naturally occurring peptide hormone that raises blood sugar, FDA-approved as emergency treatment for severe hypoglycemia.

A 36-amino-acid endogenous neuropeptide, one of the most abundant in the mammalian brain and the central nervous system's primary orexigenic (hunger-driving) signal.

A 132-amino-acid endogenous neuropeptide (processed to the ~83 aa C-terminal active form) expressed almost exclusively in a discrete population of arcuate-nucleus neurons. Acts as an inverse agonist and competitive antagonist at MC3R and MC4R — the counter-regulatory signal to α-MSH in the leptin–melanocortin appetite circuit and the defining 'hunger neuron' marker.

A 36-amino-acid hormone of the PP-fold family produced by the F-cells (PP-cells) of the pancreatic islets, isolated by James Kimmel at the University of Kansas in 1975 and characterized as a postprandial vagally-mediated anorectic hormone that signals preferentially through the Y4 receptor — together with peptide YY and neuropeptide Y, it forms the canonical PP-fold/NPY family of feeding-related peptides.

A triple monoamine reuptake inhibitor (serotonin, noradrenaline, dopamine) that produced up to 10.6% weight loss in Phase 2 trials — roughly double the efficacy of older appetite suppressants. Approved in Mexico; not yet FDA-approved.

The world's first approved dual GLP-1/glucagon receptor agonist, developed by Innovent Biologics (China). Approved in China for obesity and type 2 diabetes. Phase 3 trials showed up to 20.1% weight loss.

Zealand Pharma's long-acting amylin analog, partnered with Roche in a $5.3B deal. Phase 2b ZUPREME-1 showed 10.7% weight loss at 42 weeks with placebo-like tolerability — the 'tolerability play' in the amylin class.

Roche/Genentech's next-generation dual GLP-1/GIP receptor agonist (INN: enicepatide, assigned 2026). Phase 2 showed 22.5% placebo-adjusted weight loss at 48 weeks — competitive with retatrutide. Phase 3 ENITH program initiated Q1 2026 with two pivotal trials.

The hepatic peptide hormone of fasting and ketogenic states — and the target behind the most exciting current NASH/MASH pipeline. Native FGF21 has a half-life measured in hours; the clinical drugs are engineered Fc-fusions and PEGylated variants dosed weekly.

An endogenous 36-amino-acid gut hormone released by intestinal L-cells after meals; its active fragment PYY(3-36) is a Y2-receptor-selective satiety signal.

A biased-agonist GLP-1 receptor agonist from Sciwind Biosciences, engineered to favor Gs/cAMP signaling over β-arrestin recruitment. Phase 3 data in overweight/obese adults showed ~13.2% body weight reduction at 40 weeks. Approved or pending approval in China; not FDA-approved.

A short-acting GLP-1 receptor agonist originally approved for type 2 diabetes, now studied for slowing motor decline in early Parkinson's disease.

An endogenous 37-amino-acid gut hormone and natural dual agonist at the GLP-1 and glucagon receptors — the physiologic template behind the dual-agonist obesity drug class (cotadutide, survodutide, mazdutide).

An endogenous neuropeptide isolated from porcine spinal cord by Naoto Minamino, Kenji Kangawa, and Hisayuki Matsuo at the National Cardiovascular Center in Osaka in 1985, named for its uterus-stimulating activity but now best characterized as an anorectic feeding-suppressing neuropeptide acting at NMUR1 (peripheral) and NMUR2 (central, brain-enriched) receptors with additional roles in circadian rhythm, stress, immunity, and Th2 inflammation.

A modified fragment of human growth hormone studied specifically for fat metabolism without the growth-promoting effects of full GH.

An investigational once-weekly dual GLP-1/GIP receptor agonist from Jiangsu Hengrui, with ex-Greater China rights held by Kailera Therapeutics. Phase 3 in China produced up to 19.2% weight loss at 48 weeks; a global Phase 3 (KaiNETIC) began enrolling in January 2026.

Eli Lilly's once-weekly selective amylin receptor agonist. Phase 2 trials showed up to 20% weight loss at 48 weeks with favorable tolerability. Phase 3 enrollment began late 2025.

Pfizer's ultra-long-acting, fully-biased GLP-1 receptor agonist designed for once-monthly injection — with 12.3% placebo-adjusted weight loss at 28 weeks in Phase 2b and a 10-trial Phase 3 program planned.

A mitochondria-derived peptide that regulates metabolic homeostasis and has been called an 'exercise mimetic.'

An exercise-induced myokine that promotes browning of white adipose tissue, enhances metabolism, and shows neuroprotective effects — though bioavailability and clinical translation remain challenging.

An experimental fat-targeting peptide that selectively destroys blood vessels feeding white adipose tissue. Produced dramatic fat loss in primate studies but was discontinued due to kidney toxicity.

A selective NNMT inhibitor that reduces fat mass by boosting NAD+ and cellular energy expenditure — without affecting appetite. In mice, 11 days of treatment produced 5% weight loss and 35% reduction in white adipose tissue.

A liver- and brain-derived peptide hormone that regulates energy balance, insulin sensitivity, and endothelial function — investigated as both a cardiometabolic biomarker and a potential therapeutic target, though no clinical drug program exists yet.

A 14-amino-acid peptide hormone that activates galanin receptors 2 and 3 — lower in obesity and type 2 diabetes, investigated as a potential metabolic therapeutic and biomarker but still without any approved product or clinical trial program.

A 12-amino-acid peptide cleaved from the BRINP2 protein that activates hypothalamic POMC neurons via a non-incretin pathway. Identified by Stanford's Svensson lab using AI-driven prohormone-cleavage prediction and published in Nature (2025). Preclinical only — no human trials have been initiated as of April 2026.

A 23-amino-acid peptide proposed in 2005 by Aaron Hsueh's group at Stanford as a ghrelin-opposing anorectic hormone encoded by the same preproghrelin gene, with a contested physiological role — the original Science paper has been only partially replicated, and obestatin's identity as a true ghrelin antagonist on food intake remains one of the most public failure-to-replicate stories in peptide endocrinology.

A once-monthly dual GIP/GLP-1 receptor agonist from Eli Lilly, in Phase 3 trials for alcohol use disorder and bipolar disorder, with additional studies in obesity, asthma, and smoking cessation.