Peptide Reconstitution Calculator: How to Calculate Dilution Math Safely

Reconstitution is the process of mixing sterile bacteriostatic (BAC) water with dry, lyophilized peptide powder to create an injectable solution. Because peptides are distributed in various vial weights (e.g. 2mg, 5mg, 10mg) and syringe types carry different unit volumes (e.g. 50 units, 100 units), calculating the correct dose requires precise dilution math.

Understanding Reconstitution Math

To compute how much active compound resides in each unit of your syringe, you need three key values:

1. Vial Size (mg): The total mass of dry peptide powder inside the vial (e.g. 5mg).
2. Water Volume (mL): The amount of bacteriostatic water added to dissolve the powder (e.g. 2mL).
3. Target Dose (mcg): The specific dose weight your protocol requires (e.g. 250mcg).

Let's look at the baseline formula to find the concentration:

For example, if you add 2mL of water to a 5mg vial:
\( (5 \times 1000) \div 2 = 2500\text{ mcg/mL} \).
If your target dose is 250mcg, you need:
\( 250 \div 2500 = 0.1\text{ mL} \) (which equals 10 units on a standard U-100 syringe).

Reconstitution Best Practices

• Sterile Environment: Always clean the rubber stoppers of both vials with alcohol prep pads before mixing.
• Slow Mixing: Direct the BAC water down the inside glass wall of the peptide vial rather than spraying it directly on the powder. Swirl gently — do not shake, as peptides are fragile proteins.
• Refrigeration: Once reconstituted, most peptides should be stored in a dark refrigerator to prevent degradation.

Reconstitution Logging Inside Pepglow

Pepglow serves as a private, offline-first logging tool for your peptide cycles. Once you have performed your calculations (either manually or under the guidance of your clinician), you can easily record your planned doses, actual doses, and injection sites to keep a clear history of your protocol. The app provides visual site-rotation maps and calendars to help you maintain consistency safely, without providing automatic dosing calculations or medical recommendations.