GAC Water

GAC Water Product Profile

GAC Water is an essential laboratory and formulation supply item required for professional peptide research and cosmetic compounding applications.

Product Specifications

Parameter	Value
Composition	H₂O + Glycerin + Acetic Acid
Mol. Weight	18.02 g/mol (solvent)
Grade	USP Grade
Appearance	Clear sterile solution

Figure 1: GAC Water Overview

Application Details

1. Alternative reconstitution solvent for peptides that are sensitive to benzyl alcohol.
2. Glycerin component provides gentle pH buffering and prevents peptide aggregation.
3. Acetic acid maintains the solution at a mildly acidic pH conducive to peptide stability.
4. Ideal for copper peptides (GHK-Cu, AHK-Cu) which can precipitate in standard BAC water.
5. Eliminates the rare allergic reactions some subjects experience to benzyl alcohol.

Figure 2: Quality Metrics

Key Notes

• 1: Required solvent for copper-peptide and pH-sensitive compound reconstitution.
• 2: Provides superior stability for peptides requiring acidic environments.
• 3: Essential accessory for any comprehensive peptide research supply.

What Is GAC Water?

GAC water is a specialized reconstitution solvent composed of glycerin and acetic acid in a sterile aqueous base. It was developed as an alternative to standard bacteriostatic water for peptides that exhibit poor solubility or stability in neutral-pH solutions. The mild acidity (typically pH 3.5–4.5) provided by the acetic acid component helps maintain certain peptides in their monomeric, bioactive conformation, preventing aggregation and fibrillation that can occur at physiological pH.

When to Use GAC Water Instead of BAC Water

1. GLP-1 receptor agonists (semaglutide, tirzepatide, retatrutide) — these large peptides are prone to fibril formation at neutral pH. The acidic environment of GAC water maintains solubility and prevents visible particulate formation.
2. HGH Fragment 176-191 — this C-terminal fragment has an isoelectric point that causes precipitation in standard BAC water. GAC water keeps it in solution.
3. Benzyl alcohol-sensitive applications — GAC water contains no benzyl alcohol, making it suitable when the preservative is contraindicated.
4. High-concentration reconstitutions — the glycerin component acts as a co-solvent, improving solubility when dissolving larger peptide masses in minimal volumes.
5. Long-term storage solutions — the acidic pH and glycerin together provide enhanced stability for peptides stored in reconstituted form beyond 14 days.

Handling & Compatibility Notes

• Injection Considerations: GAC water is slightly more viscous than BAC water due to the glycerin content. Use a 29–30 gauge needle for smooth subcutaneous delivery.
• Reconstitution Technique: Follow the same gentle wall-trickle method as BAC water. The acetic acid component dissolves lyophilized cakes more rapidly—most peptides will be fully in solution within 30 seconds.
• Storage: Store at 2–8°C after opening. The absence of benzyl alcohol means GAC water relies on its low pH for microbial inhibition; strict aseptic technique is essential.
• Do Not Mix: GAC water should not be combined with BAC water in the same vial. The differing pH and preservative systems can create incompatibilities that affect peptide stability.
• Visual Inspection: GAC water is clear and colorless. Any cloudiness, particulates, or color change indicates contamination—discard immediately.