This guide covers everything needed for the reconstitution process, including equipment, concentration calculations, step by step mixing, and storage.
All information is for research and educational purposes only.
What You Need Before You Start
Before beginning reconstitution, have the following ready:
- Retatrutide lyophilised vial (20mg or 40mg)
- Bacteriostatic water (BAC water) — 10ml vial
- Insulin syringes (U-100, 1ml)
- Alcohol wipes
- Clean flat surface
All equipment must be sterile. Never reuse needles or syringes.
Add BAC WaterWhat Is Bacteriostatic Water and Why Does It Matter?
Bacteriostatic water is sterile water that contains 0.9% benzyl alcohol as a preservative. This preservative prevents bacterial and fungal growth, making BAC water ideal for multi-use vials.
BAC water is preferred over sterile water for peptide reconstitution because sterile water lacks preservatives and can only be used as a single-dose diluent.
Always use bacteriostatic water — not sterile water, not tap water.
Concentration — How Much BAC Water to Add
The amount of BAC water added determines the concentration of the final solution and therefore how much to draw per dose.
For a 10mg vial, adding 1ml of BAC water gives a concentration of 10mg/ml. Adding 2ml gives 5mg/ml.
For a 20mg Retatrutide vial, a straightforward approach used by many researchers:
Add 2ml BAC water
10mg/ml concentration
Add 4ml BAC water
5mg/ml concentration
Step by Step Reconstitution
Clean everything
Wipe the rubber stopper on both the Retatrutide vial and the BAC water vial with a fresh alcohol wipe. Allow to air dry completely.
Draw the BAC water
Insert the syringe needle into the BAC water vial and draw your chosen volume slowly.
Inject slowly down the vial wall
The bacteriostatic water should be injected slowly down the side of the vial, not forcefully onto the powder itself. Rapid injection may damage delicate peptide chains through agitation.
Mix gently
Roll the vial gently between your palms until the powder fully dissolves into a clear, colourless solution — around 30 to 60 seconds. Never shake. Vigorous shaking creates bubbles and may degrade the peptide.
Check the solution
The reconstituted solution should be completely clear and colourless. Cloudiness can indicate bacterial contamination, improper mixing, or degradation. Discard any solution that is not crystal clear.
Storage After Reconstitution
Reconstituted Retatrutide should be refrigerated at 2–8°C and is typically stable for 28–60 days depending on storage conditions. Never freeze reconstituted peptides.
Inspect for particles or discoloration before each use and discard if the solution is cloudy.
Key Storage Rules
- Refrigerate immediately after reconstitution at 2–8°C
- Never freeze the reconstituted solution
- Keep away from direct light
- Discard if solution becomes cloudy at any point
Sourcing Verified Retatrutide in the UK
Reconstitution technique only matters if the underlying peptide is what it claims to be. In the UK research market, not all vendors publish independent purity documentation.
Sculpt Labs supplies Retatrutide 20mg vials with Janoshik Analytical COAs published openly on our Purity Reports page. Current batch purity: 99%.
View Retatrutide UKFrequently Asked Questions
How much BAC water should I add to a 20mg Retatrutide vial?
For a 10mg/ml concentration add 2ml of bacteriostatic water. For a 5mg/ml concentration add 4ml. Use the Sculpt Labs calculator at sculptlabs.uk/calculator for exact draw volumes.
Can I use sterile water instead of bacteriostatic water?
Sterile water can be used but the reconstituted solution should be used within 24 hours as it contains no preservative. Bacteriostatic water is recommended for research settings requiring multi-dose use.
What should reconstituted Retatrutide look like?
Completely clear and colourless. Discard immediately if the solution appears cloudy, has visible particles, or has changed colour.
How long does reconstituted Retatrutide last?
When refrigerated at 2–8°C using bacteriostatic water, typically 28–30 days. Never freeze the reconstituted solution.
Does Sculpt Labs supply bacteriostatic water?
Yes. BAC water is available to add to any order at sculptlabs.uk/shop.
⚠ All products are supplied strictly for research and laboratory purposes only. Not for human consumption.