How should I reconstitute 36 mg of retatrutide to obtain a concentration of 4 mg per milliliter?

Reconstituting 36 mg of Retatrutide to 4 mg/mL

To achieve a concentration of 4 mg/mL from 36 mg of retatrutide, add 9 mL of sterile diluent (bacteriostatic water or sterile water for injection) to the vial.

Calculation Method

The basic reconstitution formula is straightforward:

• Desired concentration = Total drug amount ÷ Total volume
• Required volume = Total drug amount ÷ Desired concentration
• 9 mL = 36 mg ÷ 4 mg/mL 1

This yields exactly 4 mg per milliliter in the final solution.

Reconstitution Procedure

Preparation Steps

• Use aseptic technique throughout the entire reconstitution process to prevent contamination and maintain sterility 1
• Gather all necessary supplies before beginning: the retatrutide vial, appropriate volume syringe (10 mL), sterile diluent, alcohol swabs, and proper labeling materials 1
• Allow the retatrutide vial and diluent to reach room temperature (approximately 30 minutes if refrigerated) before reconstitution to ensure proper mixing 1

Mixing Technique

• Draw up exactly 9 mL of sterile diluent using a sterile syringe, ensuring accurate measurement 1
• Inject the diluent slowly down the side of the vial rather than directly onto the powder to minimize foaming 1
• Gently swirl the vial in a circular motion until the powder is completely dissolved; do not shake vigorously as this can denature the peptide 1
• Inspect the solution visually to ensure it is clear and free of particulates before use 1
• Remove any air bubbles by holding the vial upright and gently tapping the side 1

Critical Labeling Requirements

Proper labeling is essential to prevent medication errors and ensure safe administration 1:

• Patient identification (name and medical record number)
• Medication name: "Retatrutide"
• Concentration: "4 mg/mL"
• Total volume: "9 mL"
• Total drug amount: "36 mg"
• Diluent used: specify type (e.g., "bacteriostatic water")
• Date and time of reconstitution
• Preparer's initials or identification
• Expiration date/time (based on stability data or manufacturer recommendations)
• Storage requirements (typically refrigerated 2-8°C) 1

Common Pitfalls to Avoid

• Do not use expired diluent or retatrutide, as this compromises both safety and efficacy 1
• Avoid vigorous shaking, which can cause protein aggregation and reduce drug potency 1
• Do not use if the solution appears cloudy, discolored, or contains particles after reconstitution 1
• Never mix retatrutide with other medications in the same vial 1
• Ensure accurate volume measurement; even small errors in the diluent volume will alter the final concentration significantly 1

Storage and Stability

• Store the reconstituted solution in the refrigerator at 2-8°C unless manufacturer guidelines specify otherwise 1
• Protect from light during storage to maintain stability 1
• Use within the timeframe specified by stability data (typically 28 days for peptide medications when using bacteriostatic water, but verify with product-specific information) 1
• Discard any unused portion after the expiration date/time indicated on the label 1

Verification Before Administration

• Double-check the concentration calculation before first use: 4 mg/mL means each 1 mL contains 4 mg of retatrutide 1
• Confirm the dose prescribed matches what can be accurately drawn from this concentration 1
• Verify the route of administration is subcutaneous, as retatrutide is administered subcutaneously once weekly 2, 3