PeptideCompareAcetic Acid Water (2%) — EU research guide.
Acetic acid water (0.6% acetic acid / approximately 2% dilution in some formulations) is the recommended diluent for reconstituting acid-labile peptides including IGF-1, IGF-1 LR3, IGF-1 DES and PEG-MGF that do not dissolve well in bacteriostatic water.
What is Acetic Acid Water?
Acetic acid water is sterile water acidified with glacial acetic acid to a concentration of approximately 0.6% (v/v), producing a pH of around 3–4. At this acidic pH, IGF-family peptides and certain other acid-stable peptides remain soluble and structurally intact. Bacteriostatic water (benzyl alcohol at neutral pH) is unsuitable for these peptides as it causes aggregation or degradation.
When is it used instead of BAC water?
Use acetic acid water for: IGF-1 LR3, IGF-1 DES, PEG-MGF, MGF and some growth factors. Use bacteriostatic water for: BPC-157, TB-500, GHK-Cu, Epitalon, GHRPs, GHRH analogues and most general-purpose peptides. When in doubt, consult the vendor COA or supplier data sheet — the correct diluent is often specified.
Quality and sourcing considerations
Research-grade acetic acid water should be sterile-filtered through 0.22 μm membrane, produced under clean-room conditions and supplied in sealed multi-dose vials. Endotoxin testing (LAL ≤0.1 EU/mL) is the quality standard for injectable-grade solvents. Do not substitute household vinegar or non-sterile acetic acid solutions.
Potency retained over time
Each line is one storage condition: it starts at 100% and falls as potency is lost. Above the dashed 80% line the material is considered reliable — hover for exact values.
⚠ Computed from molecular properties (sequence length, cyclisation, residues prone to oxidation or deamidation, light sensitivity), per compound. Indicative only — not lab-measured per batch.
Acetic Water across EU suppliers
COA-verified EU vendors · Updated monthly