It should be labelled as bacteriostatic, specifically
Plain sterile water and bacteriostatic water aren’t interchangeable for multi-dose use; the listing should say bacteriostatic explicitly, with its benzyl alcohol content stated, not just “sterile water” or “diluent.”
Concentration and volume
A standard bacteriostatic water vial is commonly sold in 30mL multi-dose vials, though sizes vary. Checking the stated volume against what you actually need for your reconstitution plans avoids buying either far more or far less than useful.
Sourced alongside the peptide, or separately
Some UK suppliers include bacteriostatic water with a peptide order; others expect it to be sourced separately. Confirming which applies before ordering avoids a delay waiting on a second order once the peptide has already arrived.
Storage and expiry on arrival
Bacteriostatic water should arrive with a clear expiry date and be usable as-is, without needing refrigeration until first opened. Checking the expiry date on arrival, not just trusting the listing, is a simple habit worth keeping.
A quick checklist
Labelled bacteriostatic, not just sterile. Benzyl alcohol content stated. Clear expiry date. Appropriate volume for your needs. A supplier who can answer questions about it directly, not just a generic product page with no other detail.