Guide · reconstitution

How to reconstitute peptides

Reconstituting means dissolving a freeze-dried peptide powder into liquid so it can be measured and used. Here’s a clear, careful walkthrough, the supplies you need, and a calculator to get the numbers right.

Read this first

This is general educational information, not medical or dosing advice, and Chemdu does not sell or recommend injectable peptides. Only handle and use a medicine as directed by a licensed clinician, following the product’s instructions. If a peptide is prescription-only, get it and its directions from a healthcare professional.

What you’ll need

Bacteriostatic waterThe usual diluent — benzyl alcohol inhibits bacteria for multi-day use.View on Amazon → Syringes (U-100)Insulin syringes for drawing water and measuring doses in units.View on Amazon → Alcohol swabsTo wipe vial stoppers before piercing them.View on Amazon → Sharps containerFor safe disposal of used needles.View on Amazon →

As an Amazon Associate, Chemdu may earn from qualifying purchases, at no extra cost to you. General supplies shown for convenience; use only as directed by a professional.

Step by step

  1. Work out your numbers first. Decide how much bacteriostatic water to add based on your peptide amount and target dose — use the peptide calculator below to get the concentration and per-dose volume.
  2. Clean hands and surface. Wash your hands; work on a clean surface.
  3. Swab both stoppers. Wipe the tops of the peptide vial and the bacteriostatic water vial with an alcohol swab; let them dry.
  4. Draw the water. Draw your calculated volume of bacteriostatic water into the syringe.
  5. Add it slowly — down the wall. Insert the needle and let the water run down the inside wall of the peptide vial, not straight onto the powder. This protects the delicate peptide.
  6. Swirl, don’t shake. Gently swirl (or leave it) until fully dissolved. Never shake — agitation can degrade peptides.
  7. Inspect. The solution should be clear. Discard if it’s cloudy or has particles.
  8. Store correctly. Refrigerate and use within the recommended window, protected from light and heat.

Work out the numbers — free calculator

Our peptide calculator does the math for you: enter the peptide amount and water volume to get the concentration, then a target dose to get the exact syringe volume in mL and insulin units. It also shows doses-per-vial and a syringe-fill graphic.

Open the peptide calculator →

Common mistakes to avoid

  • Shaking the vial — swirl gently instead.
  • Blasting water onto the powder — aim for the vial wall.
  • Skipping the alcohol swab on the stoppers.
  • Guessing the dose — calculate it; don’t eyeball.
  • Leaving it at room temperature long-term — refrigerate.
  • Reusing needles — use a fresh one and dispose in a sharps container.

Frequently asked questions

Bacteriostatic water is common because the small amount of benzyl alcohol inhibits bacterial growth, allowing multi-day use. Sterile water is an alternative for single use. Follow your clinician’s or the product’s directions.
It depends on the peptide amount and target dose. More water dilutes it so you draw a larger, easier-to-measure volume. Use the reconstitution calculator to work out concentration and per-dose volume.
No — add water slowly down the vial wall and swirl gently. Shaking can damage delicate peptides. Let it dissolve on its own.
Generally refrigerated and used within a recommended window (often a few weeks), protected from light and heat. Follow the specific product or clinician guidance.

Related reading

Peptide calculator → Peptides, explained → Therapeutic peptides →

Not medical advice. Chemdu is an educational resource and does not sell, prescribe or supply any peptide. Always follow a licensed clinician’s instructions and the product’s directions for handling and use.