Reference

Compare peptides

Two to four compounds, field by field: identity, United States regulatory status, and what kinds of documents are on file. The table records differences. It does not rank them.

Compound 1

Compound 2

Compound 3 (optional)

Compound 4 (optional)

No winner, no score, no recommendation. Counts describe how many documents of each kind Therapept has indexed — not how well a compound works, and not how much has been published overall.

Link to this comparison: /compare?peptides=semaglutide,tirzepatide,retatrutide

Side-by-side comparison of Semaglutide, Tirzepatide, Retatrutide
Identity
	Semaglutide	Tirzepatide	Retatrutide
Class	GLP-1 receptor agonist (acylated GLP-1 analogue)	Dual GIP and GLP-1 receptor agonist	Investigational triple agonist of GIP, GLP-1 and glucagon receptors
Also listed as	Ozempic, Wegovy, Rybelsus, NN9535	Mounjaro, Zepbound, LY3298176	LY3437943, LY-3437943
Molecular formula	C187H291N45O59	C225H348N48O68	Not recorded
Molecular weight	4114 g/mol	4813.53 Da (FDA label); 4813 g/mol (PubChem)	4731.33 g/mol (average mass, widely cited for the free base)
CAS	910463-68-2	2023788-19-2	2381089-83-2
PubChem CID	56843331	156588324	Not recorded
Sequence length	Described structurally, not as a residue list	Described structurally, not as a residue list	Not recorded
Data caveat	None recorded	PubChem carries several duplicate deposits named “Tirzepatide” with identical CAS and formula. Full caveat	PubChem’s retatrutide record states a CID is not available as a discrete structure. Full caveat
United States regulatory status
Status	FDA-approved drug substance	FDA-approved drug substance	Investigational
FDA application	NDA 209637 (Ozempic), NDA 213051 (Rybelsus), NDA 215256 (Wegovy)	NDA 215866 (Mounjaro), NDA 217806 (Zepbound)	None recorded
Compounding	Subject of FDA communications on GLP-1 compounding following resolution of the shortage.	Subject of FDA communications on GLP-1 compounding following resolution of the shortage.	No FDA compounding entry recorded
WADA	Not named in this record	Not named in this record	Not named in this record
Research profile
Research purpose	Glycaemic control and chronic weight management	Dual-incretin glycaemic and weight management	Triple-agonist metabolic research
Proposed mechanism	Mimics the gut hormone GLP-1 at its receptor, increasing glucose-dependent insulin release, slowing stomach emptying and reducing appetite signalling in the hypothalamus.	Activates both the GIP and GLP-1 receptors. GLP-1 contributes appetite suppression and slowed gastric emptying; GIP contributes insulinotropic and adipose effects that are still being characterised.	Proposed triple agonism: GLP-1 and GIP effects on appetite and insulin, plus glucagon-receptor signalling in the liver and energy expenditure. The net clinical contribution of each arm is still being studied.
Human evidence	Multiple randomised controlled trials and cardiovascular outcome trials support the approved indications. This is approved-drug evidence, not research-chemical evidence.	Large randomised Phase 3 programmes (SURPASS and SURMOUNT) underpin two approved indications.	A published 48-week Phase 2 trial in 338 adults, plus Phase 3 trials registered and sponsor topline disclosures. No approved product exists.
Evidence tier	Approved drug product in the United States	Approved drug product in the United States	Phase 3 trials registered or reported
Known safety concerns	Gastrointestinal adverse effects are common and are described in the approved labelling. The label carries warnings and contraindications, including a personal or family history of medullary thyroid carcinoma or MEN2. Rapid weight loss can be accompanied by loss of lean mass; the label and clinical follow-up address this, not a supplement claim.	Gastrointestinal adverse effects are common in the trials and labelling. The label carries warnings and contraindications, including thyroid C-cell tumour contraindications. Gallbladder and pancreatic events are described in the labelling as warnings; this is not a complete safety profile.	Gastrointestinal adverse effects were reported in the Phase 2 trial. Resting heart rate increased transiently in the Phase 2 trial. The full Phase 3 safety database and any regulatory review are not public as an approved label.
Evidence gaps	Long-term outcomes beyond the trial programmes, including weight regain after stopping, are incompletely characterised. Whether any incretin directly causes or worsens hair shedding is not established by controlled evidence indexed here.	Long-term cardiovascular outcome data continue to accrue and differ by population. The relative contribution of GIP versus GLP-1 to weight loss in humans is not fully resolved.	Peer-reviewed Phase 3 results, including full adverse-event tables. Long-term cardiovascular and lean-mass outcomes. Any regulatory decision.
Head-to-head evidence	Tirzepatide has been compared with semaglutide 1 mg in the SURPASS programme. No published head-to-head trial against retatrutide exists.	Tirzepatide has been compared directly with semaglutide 1 mg in SURPASS trials. No head-to-head against retatrutide is published.	No published head-to-head trial against semaglutide or tirzepatide. Cross-trial comparisons are not head-to-head evidence.
Named pathways	GLP-1 receptor · Gastric emptying · Hypothalamic appetite signalling · Insulin secretion	GIP receptor · GLP-1 receptor · Gastric emptying · Hypothalamic appetite signalling · Insulin secretion	GIP receptor · GLP-1 receptor · Glucagon receptor · Hepatic lipid oxidation · Energy expenditure
Evidence on file
Records	4Open evidence file	3Open evidence file	2Open evidence file
Human-interventional records	2	2	2
Human-observational records	0	0	0
Animal records	0	0	0
In-vitro records	0	0	0
Reviews	0	0	0
Regulatory documents	2	1	0
Earliest indexed	2016	2021	2023
Latest indexed	2026	2023	2026

Every identity and regulatory value above is taken from the compound’s record, where its sources are listed. Evidence counts are derived from the published evidence file at build time. A missing class means no document of that kind is indexed — not that none exists.

Overlapping pathways

Named in the mechanism discussion for at least two of these compounds: GLP-1 receptor · Gastric emptying · GIP receptor · Hypothalamic appetite signalling · Insulin secretion.

Shared biology is not shared evidence. No claim of synergy is made here, and overlapping pathways do not mean the compounds have been studied together.