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Basics & Technique

How do I label my vials so I don't mix them up?

Updated 2026-05-02

Label the vial the moment you mix it. Before anything else. At minimum, write the peptide name, the date you added water, the discard date (mix date plus 28 days for BAC water), how much BAC water you added, and the resulting concentration. Lab tape and a permanent marker are fine. Use YYYY-MM-DD format so you don't second-guess the date later.

IfIf you forgot to label and don't remember when you mixed it
Thenthen treat the vial as expired - discard
IfIf you have multiple vials in the fridge
Thenthen use a small organizer or separate labeled bags
IfIf you only used part of the BAC water (for example 1 mL out of 2)
Thenthen note that - your concentration will be different from the default
Key facts
  • Label the vial with: peptide name, mix date, discard date, BAC water volume added, final concentration in mg/mL
  • Date format: YYYY-MM-DD or DD-MON-YYYY avoids month/day confusion
  • Never store unlabeled vials next to labeled ones
  • If concentration changes (different BAC water volume), update the label - don't rely on memory
  • Beyond-use dating is a USP 797 requirement for compounded sterile preparations
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