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Peptide comparison
This page compares semaglutide and retatrutide side by side, drawing on reconstitution and dosing-reference data for both. It is intended as a factual reference that lays out how each is described in its current source material rather than as guidance on use. The notes below summarize regulatory status, evidence basis, route, frequency, and the dose ranges associated with each.
Semaglutide
Retatrutide
FDA-approved prescription for labeled indications
Investigational; no FDA/UK/EU marketing approval
Current regulator label
Published Phase 2 human RCT
Subcutaneous
Subcutaneous
Once weekly
Once weekly
0.25–2.4 mg
1–12 mg
Semaglutide vs Retatrutide: at a glance
| Attribute | Semaglutide | Retatrutide |
|---|---|---|
| Regulatory status | FDA-approved prescription for labeled indications | Investigational; no FDA/UK/EU marketing approval |
| Route | Subcutaneous | Subcutaneous |
| Dosing frequency | Once weekly | Once weekly |
| Published range | 0.25-2.4 mg | 1-12 mg |
| Evidence basis | Current regulator label | Published Phase 2 human RCT |
| What the source describes | Wegovy: 0.25 mg weekly weeks 1-4, then 0.5, 1.0, 1.7; usual maintenance 2.4 mg | Phase 2 obesity trial tested 1, 4, 8 and 12 mg weekly with study-controlled escalation |
| Formulation | Commercial Wegovy is prefilled. Use only the labeled concentration or pharmacy directions. | Arithmetic only. No approved commercial concentration, label, or self-use titration exists. |
Every value is quoted from each compound's own labeling or published trial, listed in the sources below. A published range describes what has been studied or labeled - it is not a recommendation, and this page does not advise choosing one compound over the other. There is no valid dose conversion between two different compounds.
What is not established
| Compound | Established dose range | Stated limitation |
|---|---|---|
| Semaglutide | 0.25-2.4 mg | Prescription-only; oral semaglutide uses different dosing and must not be converted with this injectable calculator. |
| Retatrutide | 1-12 mg | Trial doses are not prescribing guidance; formulation and phase-3 protocols may differ. |
Sources
| Compound | Primary source | Checked |
|---|---|---|
| Semaglutide | FDA prescribing information (Semaglutide) - accessdata.fda.gov | 2026-06-24 |
| Retatrutide | New England Journal of Medicine - DOI 10.1056/NEJMoa2301972 | 2026-06-24 |
INTERACTIVE
Model the dosing curve for each
Switch between semaglutide and retatrutide to see how each builds toward steady state across a full titration. Retatrutide is investigational, so its schedule reflects trial-style escalation — edit any step to match your own plan. Estimate and arithmetic only — not medical advice.
FDA-label titration (Mounjaro / Zepbound). Half-life ≈ 5 days.
One-compartment, first-order weekly-dosing model: k = ln(2) ÷ half-life; each dose decays as e^(−k·t) and all doses are summed (superposition). Shows an estimated relative level, not an absolute plasma concentration (no volume-of-distribution or bioavailability modeling). Titration presets reflect common labeled/trial escalations; retatrutide is investigational. Estimate and arithmetic only — not medical advice. Verify against the product label and with a clinician.
Key differences
Their regulatory status differs sharply: semaglutide is an FDA-approved prescription product for its labeled indications, while retatrutide is investigational and has no FDA, UK, or EU marketing approval. The reference data also comes from different evidence tiers, with semaglutide’s figures drawn from a current regulator label and retatrutide’s from a published Phase 2 human randomized controlled trial. Both are administered subcutaneously and dosed once weekly. Semaglutide’s labeled range spans 0.25 to 2.4 mg, reflecting the Wegovy schedule of 0.25 mg weekly for weeks 1 through 4, then 0.5, 1.0, and 1.7 mg, with usual maintenance at 2.4 mg. Retatrutide’s range spans 1 to 12 mg, reflecting a Phase 2 obesity trial that tested 1, 4, 8, and 12 mg weekly under study-controlled escalation. This page does not recommend either product or any particular dose; it is not medical advice, and decisions about these medications should be made with a qualified healthcare professional.
Reference comparison only. Not medical advice; verify with a clinician, product label, pharmacist, or approved research protocol.
Frequently asked questions
How are semaglutide and retatrutide administered?
Both are subcutaneous, once-weekly compounds in the cited sources. Semaglutide is FDA-approved for its labeled indications; retatrutide is investigational with no marketing approval.
What dose ranges does this comparison reference?
The figures above — semaglutide 0.25–2.4 mg from the label and retatrutide 1–12 mg from published trials. Reference ranges only, not dosing guidance.
Can I calculate reconstitution for both here?
Yes — use the buttons above to open either calculator for the concentration (mg/mL), draw volume and U-100 syringe units.
Does this page recommend one over the other?
No. It is a neutral, source-based reference and does not assess efficacy, safety, or suitability. Those decisions belong with a licensed prescriber.