Peptides for Weight Management

14 research peptides are currently studied for weight management. This guide ranks them by evidence strength and covers their mechanisms, safety profiles, and current clinical status.

Evidence Rating: A

Category: Metabolic / GLP-1 Agonist

Semaglutide is an FDA-approved GLP-1 receptor agonist (MW ~4113.6 g/mol, molecular formula C187H291N45O59) with 94% sequence homology to human GLP-1. It is approved for type 2 diabetes (Ozempic), chronic weight management (Wegovy), and non-cirrhotic MASH (Wegovy). Developed by Novo Nordisk and first FDA-approved December 5, 2017, it is backed by the extensive STEP and SUSTAIN trial programs involving thousands of patients. There is no generic semaglutide available, and the FDA has warned about counterfeit products.

Key claims: Causes significant weight loss; Improves blood sugar control.

Evidence Rating: A

Category: Metabolic / Dual GIP-GLP-1 Agonist

Tirzepatide is a first-in-class dual GIP and GLP-1 receptor agonist developed by Eli Lilly, FDA-approved for type 2 diabetes (Mounjaro) and chronic weight management (Zepbound) including severe obstructive sleep apnea in adults with obesity. It is a 39-amino-acid peptide with a C20 fatty di-acid moiety that promotes albumin binding, enabling once-weekly dosing. Clinical trials consistently demonstrate it delivers the most substantial weight reduction among incretin-based therapies, with up to 22.5% mean body weight loss at 72 weeks.

Key claims: Superior weight loss compared to semaglutide; Improves blood sugar control.

Evidence Rating: A

Category: Metabolic / GLP-1 Agonist

Liraglutide is an FDA-approved GLP-1 receptor agonist with 97% amino acid sequence homology to endogenous human GLP-1. Developed by Novo Nordisk, it is approved as Victoza for type 2 diabetes and Saxenda for chronic weight management. It was the first GLP-1 agonist approved for obesity. While effective, it has been largely superseded by semaglutide (once-weekly dosing, greater weight loss) — liraglutide requires daily injection and achieves approximately 8% weight loss vs semaglutide's 15%.

Key claims: Clinically significant weight loss; Improves glycemic control.

Evidence Rating: A

Category: Metabolic / GLP-1 Agonist

Exenatide is a 39-amino-acid GLP-1 receptor agonist (MW ~4186.6 g/mol) originally derived from exendin-4, a peptide found in the saliva of the Gila monster (Heloderma suspectum). It was the first GLP-1 receptor agonist approved by the FDA, with Byetta (twice-daily injection) approved in April 2005 and Bydureon (once-weekly extended-release) approved in January 2012, both for type 2 diabetes. Exenatide shares approximately 53% sequence homology with human GLP-1 and is resistant to DPP-4 degradation.

Key claims: Improves glycemic control in type 2 diabetes; Produces modest weight loss.

Evidence Rating: A

Category: Metabolic / MC4R Agonist

Setmelanotide (brand name Imcivree) is a cyclic 8-amino-acid peptide (MW ~1117.3 g/mol) that acts as a melanocortin 4 receptor (MC4R) agonist. FDA-approved in November 2020 by Rhythm Pharmaceuticals, it is the first-ever treatment for chronic weight management in patients aged 6 years and older with monogenic or syndromic obesity due to POMC, PCSK1, or LEPR deficiency confirmed by genetic testing. It was subsequently approved for Bardet-Biedl syndrome (BBS) in June 2022. Setmelanotide directly restores MC4R signaling downstream of the defective leptin-melanocortin pathway.

Key claims: Significant weight loss in POMC deficiency obesity; Effective in LEPR deficiency obesity.

Evidence Rating: B

Category: Metabolic / Triple Agonist

Retatrutide is a first-in-class investigational triple hormone receptor agonist (GIP, GLP-1, and glucagon) developed by Eli Lilly. In the Phase 2 trial (Jastreboff et al., NEJM 2023, n=338), the 12 mg dose achieved 24.2% mean body weight reduction at 48 weeks, with 100% of participants achieving at least 5% weight loss. Multiple Phase 3 TRIUMPH trials are ongoing, with TRIUMPH-4 (Dec 2025) reporting average loss up to 71.2 lbs with osteoarthritis pain relief. Expected FDA approval is 2027-2028.

Key claims: Unprecedented weight loss in Phase 2; Phase 3 confirms efficacy with osteoarthritis benefit.

Evidence Rating: B

Category: Metabolic / Amylin Analog

Cagrilintide is a long-acting synthetic analog of human amylin, a peptide hormone co-secreted with insulin by pancreatic beta cells. It is being developed by Novo Nordisk both as a standalone agent and in fixed-dose combination with semaglutide (CagriSema). The CagriSema combination targets complementary appetite pathways — amylin acts on hindbrain satiety circuits while GLP-1 acts on hypothalamic and gut pathways. In the REDEFINE Phase 3 program, CagriSema achieved 20.4% weight loss at 68 weeks. Novo Nordisk filed for FDA approval in 2026.

Key claims: CagriSema achieves ~20% weight loss; Superior to semaglutide alone.

Evidence Rating: B

Category: Metabolic / Dual Agonist

Survodutide is an investigational dual glucagon/GLP-1 receptor agonist developed by Boehringer Ingelheim and Zealand Pharma. Unlike tirzepatide (GIP/GLP-1), survodutide combines glucagon and GLP-1 agonism, adding glucagon-driven hepatic fat oxidation and energy expenditure to GLP-1-mediated appetite suppression. It has shown particular promise for MASH (metabolic dysfunction-associated steatohepatitis), achieving MASH resolution in 83% of patients at the highest dose in Phase 2, and is in Phase 3 trials for both obesity and MASH.

Key claims: High rates of MASH resolution; Significant weight loss.

Evidence Rating: B

Category: Metabolic / Oral GLP-1 Agonist (Small Molecule)

Danuglipron (PF-06882961) is a small-molecule, non-peptide oral GLP-1 receptor agonist developed by Pfizer. NOTE: Danuglipron is NOT a peptide — it is a synthetic small molecule included here for comparison with peptide-based GLP-1 agonists. It is in Phase III development for type 2 diabetes and obesity. Danuglipron was initially studied as a twice-daily formulation, but Pfizer shifted focus to a once-daily modified-release formulation after the twice-daily version showed high discontinuation rates due to GI side effects.

Key claims: Oral small-molecule GLP-1 agonism is feasible; Weight loss in Phase II.

Evidence Rating: B

Category: Metabolic / Oral GLP-1 Agonist (Small Molecule)

Orforglipron (LY3502970) is a small-molecule, non-peptide oral GLP-1 receptor agonist being developed by Eli Lilly. NOTE: Orforglipron is NOT a peptide — it is a synthetic small molecule included here for comparison with peptide-based GLP-1 agonists. It is in Phase III development (ATTAIN trial program) for type 2 diabetes and obesity. Orforglipron has shown promising Phase II results with weight loss approaching injectable GLP-1 agonists, and if approved, would be the first oral non-peptide GLP-1 agonist on the market. Once-daily dosing without food restrictions makes it potentially more convenient than oral semaglutide.

Key claims: Significant weight loss approaching injectable GLP-1 agonists; Effective glycemic control in T2D.

Evidence Rating: C

Category: Metabolic / Dual GLP-1/Glucagon Agonist

Mazdutide (IBI362) is a dual GLP-1/glucagon receptor agonist co-developed by Innovent Biologics and Eli Lilly (MW 4,563.06 g/mol). It is a once-weekly injectable peptide that activates both GLP-1 and glucagon receptors, aiming to combine GLP-1-mediated appetite suppression and glucose lowering with glucagon-mediated increases in energy expenditure and hepatic fat reduction. China's NMPA approved mazdutide in June 2025 for chronic weight management and in September 2025 for glycaemic control in type 2 diabetes, making it the first dual GLP-1/glucagon agonist approved anywhere in the world.

Key claims: Significant weight loss in Chinese adults with obesity; Effective glycemic control.

Evidence Rating: C

Category: Metabolic / Dual GLP-1/Glucagon Agonist

Pemvidutide (ALT-801) is a dual GLP-1/glucagon receptor agonist being developed by Altimmune for the treatment of obesity and nonalcoholic steatohepatitis (NASH/MASH). It is a once-weekly injectable peptide designed to combine GLP-1-mediated appetite suppression with glucagon-mediated increases in energy expenditure and hepatic fat reduction. Phase II trials (MOMENTUM and IMPACT) have been completed, showing promising weight loss and liver fat reduction. Phase III development is anticipated.

Key claims: Clinically meaningful weight loss in obesity; Substantial reduction in liver fat.