Question on BAC water types
I’m reading there are two types. Wondering what experience you’re RS has had with these if you’ve used both over time?
1. Standard bacteriostatic water — sterile water with 0.9% benzyl alcohol added as a preservative (this is what “BAC water” defaults to, and what your current BA10 supply is). The benzyl alcohol prevents bacterial growth across multiple draws from the same vial, which is why it’s used instead of plain sterile water. But it is not isotonic — its saline/osmotic profile doesn’t match your body’s tissue fluid.
2. Isotonic (0.9% saline) bacteriostatic water — same benzyl alcohol preservative, but formulated with 0.9% sodium chloride so the osmotic pressure matches your blood/tissue fluid. This is the one that reduces injection-site irritation — because the solution’s saline concentration matches what’s naturally in your tissue, there’s no osmotic gradient causing local stinging, burning, or swelling at the injection site. Plain BAC water, by contrast, can sting or irritate on its own simply because it’s not isotonic — independent of whatever peptide is dissolved in it.