The most common source of peptide dosing mistakes
- Mix correctly here, then run the numbers in the Peptide calculator.
- If you want zero ambiguity, follow How to use the peptide calculator step-by-step.
- Next: protect your vial with Storage & handling.
What reconstitution actually means
Peptides are supplied as a dry (lyophilised) powder. Reconstitution is adding liquid to that powder so it can be drawn into a syringe and administered.
This step sets your concentration. If you get it wrong, every dose after it is wrong too.
What you need
- Lyophilised peptide vial (e.g. 5 mg, 10 mg)
- Bacteriostatic water (unless explicitly instructed otherwise)
- Alcohol swabs
- Insulin syringes (for injecting and/or drawing)
- Optional: larger syringe + needle (for drawing water more easily)
Know your vial strength and the exact mL you add. Those two numbers drive every calculation.
Why bacteriostatic water matters
Bacteriostatic water contains benzyl alcohol, which inhibits bacterial growth once the vial is punctured. That’s why it’s commonly used for multi-dose vials.
- Supports multi-dose use after reconstitution
- Helps reduce contamination risk (doesn’t make it “sterile-proof”)
- Improves repeatability (same dilution each time)
Understanding dilution (where most people fail)
Reconstitution does not change how much peptide you have. It changes how concentrated it is.
Example:
- Vial contains: 10 mg peptide
- You add: 2 mL bacteriostatic water
- Result: 5 mg per mL
More water does not give you more peptide. It spreads the same peptide across more volume.
Want the math handled instantly? Use the Peptide calculator after you confirm vial strength + mL added.
Step-by-step reconstitution process
- Clean the vial tops with alcohol (both peptide vial and bacteriostatic water vial).
- Draw the required mL of bacteriostatic water into a syringe.
- Inject slowly down the vial wall (avoid blasting directly onto the powder).
- Gently swirl or roll the vial until fully dissolved (do not shake aggressively).
- Label the vial (date + dilution used) so you don’t “forget and guess” later.
Common reconstitution mistakes
- Guessing dilution instead of writing it down
- Changing dilution mid-vial, then forgetting you did it
- Shaking the vial hard
- Entering the wrong vial strength into a calculator
- Entering the wrong water amount (mL) because you eyeballed it
Most “peptides didn’t work” stories are measurement and consistency errors.
Use the tools (after you understand the inputs)
Once you’ve locked the two inputs (vial mg + water mL), use tools to remove arithmetic errors.
- Peptide calculator – converts vial strength + dilution into accurate syringe volumes.
- How to use the peptide calculator – step-by-step setup so you don’t enter garbage inputs.
- If you’re tracking body composition alongside protocols: BMI calculator.
If you don’t understand the dilution, you are not allowed to trust the output.
Next: storage & handling
Reconstitution is step one. Storage determines whether your vial stays usable and consistent. Read: Storage & handling.
Key takeaways
- Reconstitution sets every future dose.
- Write down vial mg and water mL—don’t rely on memory.
- Dilution errors are the #1 peptide mistake.
- Use the Peptide calculator only after inputs are confirmed.