Step 1 - Select Your Syringe Size
Choose 0.3 mL (30 units), 0.5 mL (50 units), or 1.0 mL (100 units). Most insulin syringes are U-100, where 100 units equals 1 mL.
Free Online Tool
Free Peptide Reconstitution Calculator
Calculate exact concentration and syringe units for any peptide, including Tirzepatide, Semaglutide, BPC-157, and more. No signup required.
For tracking and calculation purposes only. Not medical advice.
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Stop re-entering the same values every time you prep a vial. Pep Pal lets you save, name, and revisit calculations with notes so your past math is easy to find. You can also compare trusted vendors in our supplier reviews.
Save Calculations with Pep PalHow to Use This Peptide Reconstitution Calculator
This calculator converts your vial amount, bacteriostatic water volume, and target dose into the exact number of syringe units to draw.
Step 2 - Enter Your Peptide Vial Amount
Input the total peptide content in milligrams (mg) shown on your vial label. Common amounts include 5 mg, 10 mg, 15 mg, and 20 mg.
Step 3 - Enter Your Bacteriostatic Water Volume
Specify how much BAC water you add in milliliters (mL). More water creates a less concentrated solution, which can be easier to measure for smaller doses.
Step 4 - Set Your Desired Dose
Enter the dose in micrograms (mcg) or milligrams (mg). Remember: 1 mg equals 1,000 mcg.
Step 5 - Read Your Results
The calculator shows concentration (mcg/mL), dose volume (mL), and the exact syringe units to draw.
Need the full walkthrough? Read the step-by-step reconstitution guide.
Example: Calculating a 250 mcg Dose
Scenario: You have a 10 mg peptide vial and add 2 mL of bacteriostatic water. You need a 250 mcg dose.
Concentration
10 mg / 2 mL = 5 mg/mL = 5,000 mcg/mL
Dose volume
250 mcg / 5,000 mcg/mL = 0.05 mL
U-100 syringe units
0.05 mL x 100 = 5 units
Pull your syringe to the 5-unit mark. The Pep Pal calculator handles this instantly for standard and non-standard vial, water, and dose combinations. If you want to keep this setup, use Pep Pal to save it.
Works With Every Reconstituted Peptide
This calculator works for lyophilized peptides reconstituted with bacteriostatic or sterile water. New to mixing? Start with the reconstitution guide.
GLP-1 and Weight Management
Tirzepatide (Mounjaro / Zepbound), Semaglutide (Ozempic / Wegovy), Liraglutide (Saxenda), Retatrutide, Survodutide, and CagriSema.
Recovery and Healing
BPC-157, TB-500, Thymosin Beta-4, GHK-Cu, and KPV.
Growth Hormone and Performance
CJC-1295, Ipamorelin, Tesamorelin, GHRP-6, GHRP-2, Sermorelin, MK-677 (Ibutamoren), and AOD-9604.
Other Research Peptides
Semax, Selank, PT-141, Melanotan II, DSIP, Epithalon, and Thymalin.
Understanding mg, mcg, IU, and Syringe Units
mg & mcg
Milligrams (mg) and micrograms (mcg) measure peptide weight. A 10 mg vial contains 10,000 mcg total peptide.
Dosing formats
Micrograms are commonly used for individual dose targets, while milligrams are often used for vial labeling and some protocol formats.
IU
International Units (IU) measure biological activity and do not convert directly to mg unless a peptide-specific conversion factor is known.
Syringe units
Syringe units measure volume. On a U-100 insulin syringe, 100 units equals 1 mL, so 5 units equals 0.05 mL.
Concentration
Concentration (mcg/mL) connects these systems. Once reconstituted, concentration determines how many units correspond to your target dose.
COA-Verified Supplier Reviews
Need a source after running your math? Compare detailed supplier pages with COA notes and discount details.
For a broader screening framework, review the grey market peptide supplier guide.
Need prep gear first? Use the peptide injection supplies checklist.
Frequently Asked Questions
How do I use a peptide reconstitution calculator?
Enter your peptide vial amount in mg, the volume of bacteriostatic water in mL, and your desired dose in mcg or mg. The calculator computes the concentration and tells you exactly how many units to draw on your insulin syringe.
Does this peptide calculator work for Tirzepatide?
Yes. This calculator works for any reconstituted peptide including Tirzepatide, Semaglutide, BPC-157, CJC-1295, Ipamorelin, and more. Enter your vial amount and water volume to get the correct syringe units.
How do you convert peptide mg to syringe units?
Divide your vial amount (in mcg) by water volume (in mL) to get concentration. Then divide your dose by concentration to get volume in mL. Multiply by 100 for U-100 syringe units. Example: 10 mg vial + 2 mL water = 5,000 mcg/mL. A 250 mcg dose = 0.05 mL = 5 units.
What is the difference between mg, mcg, and IU in peptide dosing?
Milligrams (mg) and micrograms (mcg) measure weight (1 mg = 1,000 mcg). International Units (IU) measure biological activity and vary by peptide. Syringe units measure volume - on a U-100 syringe, 100 units = 1 mL.
Is this peptide calculator free?
Yes. The Pep Pal peptide reconstitution calculator is completely free with no signup required. You can upgrade to Pep Pal to save and revisit past calculations.
Can I save my peptide calculations?
Yes. Pep Pal lets you save calculations with custom names and notes so you can revisit past reconstitutions without re-entering values every time. Learn more on the Pep Pal homepage.
How much bacteriostatic water should I add to my peptide vial?
It depends on your desired concentration. More water means a less concentrated solution that is easier to measure in small doses. Common volumes are 1-3 mL. Use the calculator to see how different water volumes affect your syringe units.
What peptides can I calculate with this tool?
Any lyophilized peptide including Tirzepatide, Semaglutide, Liraglutide, Retatrutide, BPC-157, TB-500, CJC-1295, Ipamorelin, AOD-9604, Tesamorelin, GHK-Cu, and other reconstituted peptides.
What syringe sizes does the calculator support?
The calculator supports 0.3 mL (30 units), 0.5 mL (50 units), and 1.0 mL (100 units) U-100 insulin syringes - the three most common sizes for peptide administration.
Is this calculator accurate for weight loss peptides like Tirzepatide and Semaglutide?
Yes. The math is identical for all reconstituted peptides. For GLP-1 weight loss peptides like Tirzepatide and Semaglutide, enter the vial amount, water volume, and your prescribed dose. Always follow your provider's dosing instructions.
For Laboratory Research Use Only
This tool is for informational and research calculations only and does not provide medical guidance.