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Handling Reference · Research Use Only

Reconstitution Guide: BAC Water vs Acetic Acid Water

Which solvent a lyophilized peptide dissolves in is a matter of chemistry, not preference. Most research peptides reconstitute cleanly in bacteriostatic water. Copper-complex peptides are the exception: they are poorly soluble at neutral pH and are dissolved with acetic acid water first. The table below maps every peptide in our catalog to the solvent it should be reconstituted with.

BAC waterBacteriostatic water

0.9% benzyl alcohol in sterile water · pH ~5.7

The default solvent for most research peptides. The benzyl alcohol is bacteriostatic, so a reconstituted vial stays stable for multi-week bench use when kept refrigerated.

AA waterAcetic acid water

~0.6% acetic acid in sterile water · pH ~3.0

A mildly acidic solvent for peptides that will not fully dissolve in neutral water — notably copper-complex peptides, whose copper can precipitate above ~pH 7.5. The peptide is dissolved in a small volume of acetic acid water first, then topped up with bacteriostatic water.

Solvent by peptide

PeptideSolventNotes
BPC-157BAC waterDissolves cleanly in bacteriostatic water.
TB-500BAC waterDissolves cleanly in bacteriostatic water.
BPC-157 / TB-500 BlendBAC waterDissolves cleanly in bacteriostatic water.
SemaxBAC waterDissolves cleanly in bacteriostatic water.
CJC-1295 (No DAC) / Ipamorelin BlendBAC waterDissolves cleanly in bacteriostatic water.
TesamorelinBAC waterDissolves cleanly in bacteriostatic water.
SemaglutideBAC waterDissolves cleanly in bacteriostatic water.
GLP-2 TZBAC waterDissolves cleanly in bacteriostatic water.
GLP-3 RTBAC waterDissolves cleanly in bacteriostatic water.
SermorelinBAC waterDissolves cleanly in bacteriostatic water.
CJC-1295 (No DAC)BAC waterDissolves cleanly in bacteriostatic water.
IpamorelinBAC waterDissolves cleanly in bacteriostatic water.
MOTS-cBAC waterDissolves cleanly in bacteriostatic water.
SS-31BAC waterDissolves cleanly in bacteriostatic water.
EpitalonBAC waterDissolves cleanly in bacteriostatic water.
N-Acetyl Epitalon AmidateBAC waterDissolves cleanly in bacteriostatic water.
PinealonBAC waterDissolves cleanly in bacteriostatic water.
TestagenBAC waterDissolves cleanly in bacteriostatic water.
VesugenBAC waterDissolves cleanly in bacteriostatic water.
GlutathioneBAC waterDissolves cleanly in bacteriostatic water.
SelankBAC waterDissolves cleanly in bacteriostatic water.
DSIPBAC waterDissolves cleanly in bacteriostatic water.
PE-22-28BAC waterDissolves cleanly in bacteriostatic water.
AdamaxBAC waterDissolves cleanly in bacteriostatic water.
SNAP-8BAC waterDissolves cleanly in bacteriostatic water.
KPVBAC waterDissolves cleanly in bacteriostatic water.
ARA-290BAC waterDissolves cleanly in bacteriostatic water.
Thymosin Alpha-1BAC waterDissolves cleanly in bacteriostatic water.
PT-141BAC waterDissolves cleanly in bacteriostatic water.
Oxytocin AcetateBAC waterDissolves cleanly in bacteriostatic water.
GHK-CuAA waterCopper tripeptide — the copper complex is poorly soluble at neutral pH and can precipitate in plain bacteriostatic water.
GLOW Peptide BlendAA waterContains GHK-Cu, so the whole blend follows the copper-peptide rule — dissolve with acetic acid water first, then top up.
AHK-CuAA waterCopper tripeptide (blue tint) — the copper complex is poorly soluble at neutral pH, like GHK-Cu.
KLOW BlendAA waterContains GHK-Cu, so the blend follows the copper-peptide rule — dissolve with acetic acid water first.
AOD-9604AA waterHydrophobic hGH fragment (176-191) that can be slow to dissolve at neutral pH; slightly acidic water aids solubility.
IGF-1 LR3AA waterLarger, less-soluble growth-factor analog; commonly reconstituted with dilute acetic acid water.
Melanotan IAA waterRelatively hydrophobic melanocortin peptide; slightly acidic water helps it dissolve (no copper involved).
Melanotan IIAA waterHydrophobic cyclic melanocortin peptide; slightly acidic water helps it dissolve (no copper involved).
Kisspeptin-10AA waterHydrophobic peptide that clumps in plain bacteriostatic water; dissolve in dilute acetic acid water first, then top up.

Rows shown with the AA water badge are the acetic-acid exceptions; every other peptide in the catalog uses bacteriostatic water.

Using acetic acid water

For a copper-complex peptide, a two-step approach dissolves the powder at low pH while preserving the bacteriostatic agent for storage:

  1. 1Add a small volume (about 0.1–0.2 mL) of ~0.6% acetic acid water down the vial wall — avoid spraying directly onto the powder.
  2. 2Swirl gently (do not shake) until the solution clears — typically one to two minutes.
  3. 3Dilute to the target working volume with bacteriostatic water. Keep the solution below ~pH 7.5 so the copper complex stays in solution.

General handling: reconstitute slowly down the vial wall, never shake, and let the powder dissolve on its own. Hold reconstituted solution at 4°C for short-term use or aliquot at -80°C for longer stability; store undissolved lyophilized powder at -20°C, sealed and protected from light.

Frequently asked questions

  • What is the difference between bacteriostatic water and acetic acid water?

    Bacteriostatic water is sterile water with 0.9% benzyl alcohol (pH ~5.7); the benzyl alcohol keeps a reconstituted vial stable for multi-week bench use. Acetic acid water is sterile water with roughly 0.6% acetic acid (pH ~3.0), used for peptides that will not fully dissolve at neutral pH.

  • Which peptides need acetic acid water instead of bacteriostatic water?

    In this catalog, the copper-complex peptides — GHK-Cu and the GLOW blend, which contains GHK-Cu. The copper complex is poorly soluble at neutral pH and can precipitate in plain bacteriostatic water, so it is dissolved in acetic acid water first and then topped up. Every other peptide here reconstitutes cleanly with bacteriostatic water.

  • How do you use acetic acid water to reconstitute a peptide?

    Add a small volume (about 0.1–0.2 mL) of ~0.6% acetic acid water down the vial wall, swirl gently until the powder clears, then dilute to the target volume with bacteriostatic water. This dissolves the peptide at low pH while preserving the bacteriostatic agent for longer storage.

  • How is reconstituted peptide stored?

    Reconstituted solution is held at 4°C for short-term research use, or aliquoted and frozen at -80°C for longer stability. Lyophilized (undissolved) powder is stored at -20°C, sealed and protected from light.

Browse research overviews for every peptide in the catalog.

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All information here is provided for laboratory and research reference only. Products are sold strictly for in-vitro research and development and are not for human or veterinary use.