SURMOUNT-5 Head-to-Head
Cost-effectiveness analysis confirmed tirzepatide superiority for weight loss; semaglutide remains the clinical workhorse with strongest cardiovascular data.
[1]Semaglutide
GLP-1S (Ozempic, Wegovy, Rybelsus)
FDA approved (Ozempic, Wegovy, Rybelsus)GLP-1 and GIP
A synthetic 31-amino-acid GLP-1 receptor agonist developed by Novo Nordisk. The most clinically established GLP-1 receptor agonist in the world, with full FDA approval across three formulations and the broadest evidence base of any GLP-1 agent.
Ozempic is FDA approved for type 2 diabetes management, Wegovy is FDA approved for chronic weight management, and Rybelsus is an FDA approved oral formulation for T2D.
Cardiovascular outcomes, weight loss, glycemic control, and emerging indications including MASH, MASLD, CKD, and dementia prevention give semaglutide the broadest evidence base of any GLP-1 agent.
At a glance
- Type
- Synthetic 31-amino-acid GLP-1 receptor agonist
- Developer
- Novo Nordisk
- Formulations
- Ozempic (T2D), Wegovy (chronic weight management), Rybelsus (oral, T2D)
- Regulatory
- FDA approved across three formulations
- Dosing
- Once weekly (Ozempic, Wegovy); once daily oral (Rybelsus)
- Boxed warning
- Medullary thyroid carcinoma / MEN2 personal or family history (GLP-1 class)
What the research supports
Semaglutide is the comparator against which all newer GLP-1, GLP-1/GIP, and triple agonists are measured, with proven cardiovascular benefit and the broadest indication set in the class.
Incretin Class Meta-Analysis
85 RCTs, 90,977 participants: GLP-1 receptor agonists reduce SBP 3.4 mmHg, DBP 0.9 mmHg, and all-cause mortality 18 percent across class.
[2]Obesity Pharmacotherapy Review
Reviewed as the foundation against which next-generation multi-receptor agonists and metabolic modulators are measured.
[3]CV Outcomes (SELECT, SUSTAIN-6, PIONEER 6)
Established cardiovascular risk reduction in T2D with CVD and in obesity with established CVD, including the SELECT trial in adults with obesity and CVD without diabetes.
[4]Summary of key findings
Foundation of the GLP-1 Class
Multiple FDA approvals, the broadest evidence base of any weight loss or diabetes peptide, and the most accessible commercial supply post-2024.
Proven Cardiovascular Benefit
SELECT trial established CV risk reduction in obesity with established CVD; SUSTAIN-6 and PIONEER 6 established CV benefit in T2D.
Tirzepatide Superior on Weight Loss
SURMOUNT-5 demonstrated tirzepatide superiority, but semaglutide retains stronger CV outcomes and longer real-world track record.
Lean Mass and GI Expectations
Up to 30 to 40 percent of weight lost can be lean mass; resistance training and protein 1.6 to 2.0 g/kg essential. Nausea is the rule during titration.
Dosing guide
From published protocols. Licensed provider supervision assumed throughout.
- Wegovy / Weight Management Titration
- Weeks 1 to 4: 0.25 mg. Weeks 5 to 8: 0.5 mg. Weeks 9 to 12: 1.0 mg. Weeks 13 to 16: 1.7 mg. Weeks 17 to 20: 2.4 mg weekly maintenance.
- Ozempic / T2D Titration
- Start 0.25 mg weekly, titrate to 0.5, 1.0, 2.0 mg as needed for glycemic control; maximum 2.0 mg weekly.
- Rybelsus / Oral T2D
- 3 mg, 7 mg, or 14 mg daily; empty stomach with 4 oz water; wait 30 minutes before food or other oral medications.
- Compounded Use
- Titration similar to FDA approved protocols; some practitioners use intermediate doses (1.25, 1.5 mg) or extended titration windows.
Vial reference
Units are for a U-100 insulin syringe (100 units = 1 mL), computed from the vial concentration.
| Vial | Dose range | Units per dose | Frequency | Notes |
|---|---|---|---|---|
| GLP-1 S 2 mg / 1 mL | 250 mcg to 2.5 mg | 12.5 to 125 units | 1x per week | 0.02 mg per unit. Starting dose 250 mcg. |
| GLP-1 S 5 mg / 1 mL | 250 mcg to 2.5 mg | 5 to 50 units | 1x per week | 0.05 mg per unit. |
| GLP-1 S 10 mg / 2 mL | 250 mcg to 2.5 mg | 5 to 50 units | 1x per week | 0.05 mg per unit. |
| GLP-1 S 20 mg / 4 mL | 250 mcg to 2.5 mg | 5 to 50 units | 1x per week | 0.05 mg per unit. |
| GLP-1 S 50 mg / 5 mL | 250 mcg to 2.5 mg | 2.5 to 25 units | 1x per week | 0.1 mg per unit. |
| FDA titration (Wegovy) | 0.25 / 0.5 / 1.0 / 1.7 / 2.4 mg | 1x per week | 4 weeks per step. |
Reference ranges as published in the source protocol document, not a prescription. To work out the draw for a specific vial and dose, use the Peptide Calculator.
Bottom line
Semaglutide is the foundational GLP-1 receptor agonist and the first stop for most patients starting GLP-1 therapy: established safety, predictable response, and accessible commercial supply. For patients with established cardiovascular disease, semaglutide has stronger CV outcomes data than tirzepatide; for pure weight loss without CVD priority, tirzepatide is more potent (SURMOUNT-5).
Slow titration is the floor for tolerability. Lean mass loss is real; resistance training and adequate protein are essential. FDA enforcement against compounded semaglutide intensified in 2024 to 2025 with restored commercial supply, so verify current pharmacy compliance. Emerging indications (MASH, CKD, dementia prevention) make it one of the most actively researched drugs in medicine.
Weight Management
2.4 mg weekly maintenance produces substantial weight loss in adults with obesity.
Cardiovascular Protection
SELECT trial established CV risk reduction in obesity with established CVD.
Glycemic Control
T2D HbA1c reduction with dose-dependent improvement and proven outcomes data.
References
Citations sourced from PubMed and verified against the PubMed record.
- 1Johansson et al., 2026 SURMOUNT-5 Cost-Effectiveness: Tirzepatide vs Semaglutide
- 2Basile et al., 2026 Incretin-Based Therapies on Blood Pressure Meta-Analysis
- 3Lempesis and Dalamaga, 2026 Obesity Pharmacotherapy Reimagined: Multi-Receptor Agonists Review
- 4Lincoff et al., 2023 SELECT Trial: Semaglutide Cardiovascular Outcomes in Obesity with CVD
Regulatory status, cautions and contraindications
Boxed Warning Contraindication
Medullary thyroid carcinoma / MEN2 personal or family history is a boxed-warning contraindication for the GLP-1 class. Document family history before prescribing. Pregnancy contraindicated; discontinue at least 2 months before planned conception.
Legal disclaimer
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
This peptide overview is for informational purposes only and does not constitute medical advice. The information provided here is not intended to diagnose, treat, cure, or prevent any disease. Peptide therapies should only be used under the guidance of a licensed healthcare provider, who can assess individual health needs and determine appropriate dosing and administration.
Always consult your healthcare provider before starting any new treatment, as misuse or improper dosing may lead to adverse effects. The efficacy and safety of peptide therapies have not been fully established in all cases, and ongoing medical supervision is essential.