Retatrutide Dosage Chart: Week-by-Week Schedule
Note: Retatrutide is a once-weekly injection — there is no standard retatrutide daily dosage. The weekly dose shown in this retatrutide dose chart is administered as a single subcutaneous injection each week.
Some protocols use slightly different schedules. Clinical trials tested various escalation patterns, including jumping from 4 mg directly to 8 mg. The table above reflects the most gradual approach, which tends to produce fewer side effects.
Why Gradual Dose Increases Matter
Jumping straight to higher doses causes problems. In Phase 2 trials, participants who started at 4 mg instead of 2 mg experienced nearly double the rate of GI symptoms. Nausea, vomiting, diarrhea, and stomach pain all increased.
The gradual approach works because your gut needs time to adapt. Retatrutide activates three different hormone receptors: GLP-1, GIP, and glucagon. Each one affects digestion. Flooding your system with high doses before it adjusts leads to miserable side effects and higher dropout rates.
Four weeks per dose level is the standard pace. If side effects hit hard, your provider might keep you at the same dose for an extra two to four weeks before moving up.
Weight Loss Result
Not all doses produce equal results. The Phase 2 trial data showed a clear pattern: higher doses meant more weight loss.
At 24 weeks:
- 1 mg group: 7.2% body weight reduction
- 4 mg group: 12.9% reduction
- 8 mg group: 15.7% reduction
- 12 mg group: 17.5% reduction
- Placebo: 1.6% reduction
At 48 weeks:
- 1 mg group: 8.7% reduction
- 12 mg group: 24.2% reduction
- Placebo: 2.1% reduction
The 12 mg group stood out. Every single participant in that group lost at least 5% of their body weight. 93% lost 10% or more. 83% hit the 15% threshold.
For context, losing 24% of your body weight in under a year represents dramatic results. Someone weighing 250 pounds at baseline would drop roughly 60 pounds on average.
ℹ️ Retatrutide Injection Vial & Doses for Adults: R-30 vials (30mg lyophilized) are the standard research format for adults following a full escalation protocol. A single 30mg vial covers approximately 3–4 weeks at mid-range doses (8–12mg/week). For the 2mg–12mg adult escalation schedule, expect to use 1–2 vials per month at peak dosing. Always reconstitute with bacteriostatic water and dose subcutaneously.
Retatrutide Dosage for Beginners
If you’re new to GLP-1 class drugs, the recommended retatrutide starting dose is 1 mg per week for the first 4 weeks. This beginner dose allows your digestive system to adapt before escalation. Beginners should follow the conservative titration path in the retatrutide dosage chart above and should not skip dose levels regardless of perceived tolerance.
For experienced researchers who have previously tolerated semaglutide or tirzepatide, starting at 2 mg weekly is acceptable. Never start directly at 4 mg or higher — faster escalation dramatically increases the rate of GI side effects and protocol dropout.