Peptides for Metabolic Health

33 research peptides are currently studied for metabolic health. 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 / Mitochondrial

SS-31 (Elamipretide) is a mitochondria-targeted tetrapeptide that selectively concentrates in the inner mitochondrial membrane, binding to cardiolipin and stabilizing cristae structure. It is being developed by Stealth BioTherapeutics for mitochondrial diseases, heart failure, and age-related mitochondrial dysfunction. It has undergone multiple Phase I–III clinical trials, including the TAZPOWER trial for Barth syndrome.

Key claims: Improves mitochondrial function; Reduces cardiac dysfunction.

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 / GLP-1 Agonist

Dulaglutide (brand name Trulicity) is a once-weekly GLP-1 receptor agonist developed by Eli Lilly, FDA-approved in September 2014 for type 2 diabetes. It is a fusion protein consisting of a GLP-1 analog covalently linked to a modified human IgG4 Fc fragment via a small peptide linker (MW ~59,670 g/mol). The Fc fusion extends its half-life to approximately 5 days, enabling once-weekly dosing. Dulaglutide is administered via a single-dose pen device that does not require reconstitution.

Key claims: Effective glycemic control in type 2 diabetes; Produces clinically meaningful weight loss.

Evidence Rating: A

Category: Metabolic / GLP-1 Agonist

Lixisenatide is a once-daily GLP-1 receptor agonist (MW ~4858.5 g/mol) based on the exendin-4 scaffold, with a modified C-terminal tail containing six lysine residues. It was developed by Sanofi and FDA-approved in July 2016 (Adlyxin) for type 2 diabetes. It is also marketed as Lyxumia outside the United States. Lixisenatide is available in a fixed-ratio combination with insulin glargine as Soliqua 100/33.

Key claims: Reduces HbA1c in type 2 diabetes; Potent reduction of postprandial glucose.

Evidence Rating: A

Category: Metabolic / GLP-1 Agonist

Albiglutide (brand name Tanzeum in the US, Eperzan in Europe) was a once-weekly GLP-1 receptor agonist consisting of two copies of a modified GLP-1 sequence fused to human albumin (MW ~72,970 g/mol). Developed by GlaxoSmithKline, it was FDA-approved in April 2014 for type 2 diabetes. GSK voluntarily withdrew Tanzeum from the market in July 2018 for commercial reasons (low market uptake), not due to safety concerns. The HARMONY Outcomes trial subsequently demonstrated cardiovascular benefit.

Key claims: Reduces HbA1c in type 2 diabetes; Reduces major adverse cardiovascular events.

Evidence Rating: A

Category: Metabolic / Amylin Analog

Pramlintide (brand name Symlin) is a synthetic analog of amylin, a 37-amino-acid pancreatic hormone co-secreted with insulin from beta cells (MW ~3949.4 g/mol). FDA-approved in March 2005, it is the only amylin analog approved for clinical use and is indicated as adjunctive therapy for type 1 and type 2 diabetes patients on mealtime insulin who have failed to achieve adequate glycemic control. Pramlintide has three proline substitutions (positions 25, 28, 29) that prevent the amyloid aggregation inherent to native human amylin.

Key claims: Reduces postprandial glucose excursions; Reduces HbA1c in T1D and T2D.

Evidence Rating: A

Category: Metabolic / Bone Health

Calcitonin (salmon) is a synthetic 32-amino-acid peptide hormone (MW ~3431.9 g/mol) identical to calcitonin produced by the ultimobranchial glands of salmon. It is FDA-approved for the treatment of postmenopausal osteoporosis (nasal spray), hypercalcemia of malignancy (injection), and Paget disease of bone (injection). Salmon calcitonin is approximately 40-50 times more potent than human calcitonin at inhibiting osteoclast activity. It is no longer a first-line therapy for osteoporosis due to the availability of more effective agents and a potential cancer risk signal.

Key claims: Reduces vertebral fracture risk in postmenopausal osteoporosis; Reduces bone pain in Paget disease.

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.