Peptide reconstitution guide

Research use only. The math and procedures below are written for laboratory researchers working in a controlled environment. Nothing on this page is medical or dosing advice for human use.

1. What you need

• The lyophilized peptide vial, equilibrated to room temperature (5–10 minutes out of the freezer)
• Bacteriostatic water (0.9% benzyl alcohol in sterile water) — most common general-purpose solvent
• Sterile syringes — typically 3 mL with a 21G filling needle, plus 1 mL insulin (U-100) syringes for aliquoting
• Alcohol swabs
• Fresh nitrile gloves

2. The basic math

The relationship between solvent volume, peptide mass, and concentration is simple:

Concentration (mg/mL) = Peptide mass (mg) ÷ Solvent volume (mL)

For insulin syringes graduated in U-100 ("100 units = 1 mL"), 1 unit = 0.01 mL. Once you know your concentration, the dose-per-unit becomes:

mcg per unit = Concentration (mg/mL) × 10

3. Worked examples

5 mg vial reconstituted with 2 mL BAC water

• Concentration = 5 ÷ 2 = 2.5 mg/mL
• Per insulin unit = 2.5 × 10 = 25 mcg
• 10 units on the syringe = 250 mcg of peptide

10 mg vial reconstituted with 2 mL BAC water

• Concentration = 10 ÷ 2 = 5 mg/mL
• Per insulin unit = 5 × 10 = 50 mcg
• 20 units = 1,000 mcg = 1 mg

5 mg vial reconstituted with 1 mL BAC water

• Concentration = 5 mg/mL
• Per insulin unit = 50 mcg

4. Step-by-step procedure

1. Wipe the rubber stopper of both the BAC water vial and the peptide vial with an alcohol swab and let air-dry.
2. Draw the desired volume of BAC water into a 3 mL syringe — typical volumes are 1 mL, 2 mL, or 3 mL.
3. Inject slowly down the inside wall of the peptide vial, not directly onto the lyophilized cake. This minimizes foaming and protects the molecule from shear.
4. Swirl gently — do not shake. Most peptides dissolve fully within 30 seconds. The solution should be clear and colorless. Cloudy solutions indicate either incompatibility with the chosen solvent or contamination.
5. Label the vial with reconstitution date, solvent, and resulting concentration.
6. Store at 2–8°C. For long-term storage of multiple aliquots, transfer to small sterile vials and freeze at -20°C.

5. Solvent compatibility quick reference

Peptide class	Typical solvent	Notes
GHRPs (Ipamorelin, GHRP-2/6, Hexarelin)	BAC water	Highly soluble; clear within seconds
GHRH analogs (CJC-1295, Sermorelin, Mod GRF 1-29)	BAC water	Soluble; avoid agitation
BPC-157 / TB-500	BAC water	Soluble; some lots benefit from gentle warming
Melanotan-1 / Melanotan-2	BAC water	Solution may have a faint yellow tint
GHK-Cu	BAC water	Solution is light blue — the copper is the reason
Selank / Semax	BAC water or sterile saline	Highly soluble
Hydrophobic / membrane-active (LL-37, KPV)	0.1% acetic acid then dilute with BAC water	Test with small aliquot first

6. Sterile-handling checklist

• Wash hands and put on fresh gloves before opening any vial
• Use a fresh needle for every draw — never re-use
• Keep the BAC water vial upright; never recap a needle by hand
• Dispose of sharps in an approved biohazard sharps container
• Discard any vial showing visible particulates, color change, or a torn stopper

7. Common mistakes

• Shaking the vial — peptides denature under shear; always swirl.
• Using cold solvent on a still-frozen peptide — equilibrate the lyophilized vial to room temperature first to avoid moisture condensation inside the vial.
• Mixing up "mg" and "mcg" — most research-peptide doses are in micrograms; double-check the math.
• Re-freezing reconstituted solution — multiple freeze/thaw cycles degrade most peptides. Aliquot first, then freeze.