GLP-1 receptor agonists work by slowing gastric emptying and amplifying satiety signaling. The same mechanism that produces weight loss also produces nausea, vomiting, and (in some patients) constipation if you start at the maintenance dose. Titration (slowly stepping up the weekly dose) gives the gut time to adapt. That's why every FDA-approved GLP-1 has a multi-month escalation schedule baked into the label.
Why titration exists
The four most-discussed protocols
| Drug | Indication | Schedule | Maintenance |
|---|---|---|---|
| Ozempic (semaglutide) | Type 2 diabetes | 0.25 → 0.5 → 1.0 → 2.0 mg, every 4 weeks | 2.0 mg/week |
| Wegovy (semaglutide) | Chronic weight management | 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg, every 4 weeks | 2.4 mg/week |
| Mounjaro / Zepbound (tirzepatide) | T2DM / weight | 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, every 4 weeks | 15 mg/week (or 10/12.5 if better tolerated) |
| Retatrutide (investigational) | Phase 3 | 2 → 4 → 6 → 8 → 10 → 12 mg, every 4 weeks | Investigational; not FDA-approved |
Our GLP-1 dose escalator computes each row plus the U-100 syringe units to draw from a compounded vial.
What "every 4 weeks" really means
Standard titration is minimum every 4 weeks. Many patients do better holding 8 weeks at a step before climbing, particularly at the 5 mg → 7.5 mg jump for tirzepatide, where GI side effects spike. Your physician manages this; the schedule is a starting point, not a contract.
Sulfur burps and other GI side effects
The most universally cited side effect of tirzepatide is "sulfur burps": a transient effect of slowed gastric emptying combined with high-fat meals. Strategies that help: smaller meals, fewer high-fat meals, eat slowly, hydrate aggressively. The effect typically dissipates within 2–4 weeks of each titration step.
Why retatrutide matters
Retatrutide is a triple agonist (GLP-1 + GIP + glucagon) developed by Eli Lilly. Phase 2 data (2023) showed up to 24% body weight reduction at 12 mg weekly. It's the first GLP-1-class molecule to credibly threaten tirzepatide on efficacy. FDA approval is anticipated for 2026–27.
Compounded vs brand
The FDA closed compounded GLP-1 access for tirzepatide in February 2025 and for semaglutide in April–May 2025. As of May 2026, brand product (Mounjaro, Zepbound, Wegovy, Ozempic) is the legal channel in the US. Compounded supply remains widespread in research / gray markets globally but operates outside FDA oversight; we cover the regulatory landscape in our research brief.
Where to learn more
- Semaglutide directory page
- Tirzepatide directory page
- Retatrutide directory page
- Sema vs Tirz vs Reta comparison
Disclaimer
Wegovy®, Ozempic® are registered trademarks of Novo Nordisk; Mounjaro®, Zepbound® of Eli Lilly. DoseVault is independent and unaffiliated. This is educational content; titration must be supervised by a licensed prescriber.
Not medical advice
Information on DoseVault is for educational purposes only and is not a substitute for medical advice, diagnosis, or treatment from a qualified healthcare provider.