Retatrutide Dosage Protocol

Quick Start

The short version

If you only read one thing, read this. The four cards below are the whole protocol in plain English — the sections that follow just add the detail.

Dosage Chart

Handling

Dosing & Reconstitution Guide

Add 2.0 mL bacteriostatic water slowly to the 10 mg vial. Swirl gently until fully dissolved into a clear solution. At 5 mg/mL, 2 mg equals 40 units (0.4 mL) on a U-100 insulin syringe.

Subcutaneous Protocol

Frequency: once weekly subcutaneously. Retatrutide has a long circulating half-life supporting weekly dosing. Slow uptitration reduces GI adverse effects commonly reported with incretin agonists.

Supplies Needed

Plain-English Glossary

Jargon, translated

A quick decoder for the terms you'll see across this page.

Subcutaneous (subQ)

Injected into the fatty layer just under the skin — not into muscle or vein. Easier and less painful than an IM shot.

Reconstitution

Mixing a dry powder with liquid (bacteriostatic water) to turn it into an injectable solution.

Lyophilized

Freeze-dried. The peptide arrives as a dry powder so it stays stable during shipping.

Bacteriostatic water

Sterile water with a tiny amount of preservative that prevents bacteria growth — used to mix peptides.

Units (on an insulin syringe)

The small tick marks on a U-100 syringe. 100 units = 1 mL. Most doses are just a few units.

Half-life

How long it takes your body to clear half of a dose. Guides how often you inject.

Titration

Starting low and slowly increasing the dose so your body can adjust.

Protocol Overview

• Goal: Support metabolic research on multi-receptor incretin signaling.
• Schedule: Once weekly subcutaneous injection, same day each week.
• Dose range: 2–12 mg per administration, titrated slowly.
• Storage: 2–8 °C after reconstitution, protected from light.

Dosing Protocol

• Start: 2 mg once weekly for four weeks to assess tolerance.
• Titrate in ~2 mg increments every 4 weeks if tolerated.
• Timing: Consistent day of the week improves protocol adherence.
• Cycle length: Reference protocols run 12–24 weeks, then reassess.

Storage Instructions

• Lyophilized product: room temperature, sealed and protected from light. Refrigeration acceptable.
• Reconstituted product: 2–8 °C (35.6–46.4 °F) refrigerated, protected from light.
• Do not freeze reconstituted solution.
• Allow to reach room temperature before administration to reduce injection-site response.

Important Notes

• Use a new sterile syringe for each administration.
• Rotate injection sites (abdomen, thighs, upper arms) to reduce local irritation.
• Discard the vial if the solution becomes cloudy, discolored, or shows particulates.
• Document daily dose and site rotation for consistency.
• GI effects (nausea, early satiety) are dose-dependent — slow titration is the primary mitigation.

Mechanism

How This Works

Potential Benefits & Side Effects

• Substantial reductions in body weight reported in phase-2 trials.
• Improved glycemic parameters in type-2 diabetes research.
• Reduced hepatic steatosis markers in metabolic studies.
• Commonly reported adverse effects: nausea, diarrhea, constipation — usually dose-limited.
• Investigational; long-term safety data still emerging.

Lifestyle Factors

• Prioritize protein intake to preserve lean mass during weight reduction.
• Stay well hydrated to offset GI-related fluid loss.
• Regular resistance training helps preserve muscle during caloric deficit.
• Avoid large high-fat meals near injection day to reduce GI discomfort.

Injection Technique

1. 1. Clean the vial septum and injection site with alcohol; allow to dry.
2. 2. Draw the target volume slowly to avoid foaming the peptide.
3. 3. Pinch a skinfold; insert the needle at 45–90° into subcutaneous tissue.
4. 4. Do not aspirate for subcutaneous injections; inject slowly and steadily.
5. 5. Rotate sites systematically (abdomen, thighs, upper arms) to avoid lipohypertrophy.

References

1. 1

   Jastreboff et al., NEJM (2023)

   Retatrutide phase-2 trial in obesity — 48-week results

   View source
2. 2

   Rosenstock et al., Lancet (2023)

   Retatrutide in type-2 diabetes

   View source
3. 3

   Coskun et al. (2022)

   Pharmacology of the GIP/GLP-1/glucagon triple agonist retatrutide

   View source