Peptide Reconstitution Calculator
Know exactly what to draw. Enter your vial, the bacteriostatic water you added and your dose — get the exact units on a U-100 insulin syringe.
Step 1
Your vial & dose
Start from a common vial
Step 2
Step 3
Syringe size
Smaller barrels have finer marks, which makes small doses easier to read.
Live syringe preview · 100-unit
Draw to
5 units
= 0.05 mL of liquid
5 units falls between the 4 and 6 marks on this syringe. A 0.5 mL or 0.3 mL syringe is marked every unit and is easier to read.
- Concentration
- 5 mg/mL
- Each unit contains
- 50 mcg
- Your dose
- 250 mcg
- Doses per vial
- 40
Show the math
- Concentration = 10 mg ÷ 2 mL = 5 mg/mL
- Volume = 0.25 mg ÷ 5 mg/mL = 0.05 mL
- Units = 0.05 mL × 100 = 5 units
Quick reference
Units → dose at your concentration
5 mg/mL · 50 mcg per unit
2 units
100 mcg
0.02 mL
5 units
250 mcg
0.05 mL
10 units
500 mcg
0.1 mL
15 units
750 mcg
0.15 mL
20 units
1 mg
0.2 mL
25 units
1.25 mg
0.25 mL
30 units
1.5 mg
0.3 mL
40 units
2 mg
0.4 mL
50 units
2.5 mg
0.5 mL
60 units
3 mg
0.6 mL
75 units
3.75 mg
0.75 mL
100 units
5 mg
1 mL
Explore by medication
Peptide dosage calculators
Tirzepatide
GIP / GLP-1 receptor agonist
Common vials: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg
Open calculator
FDA-approved (brand)Semaglutide
GLP-1 receptor agonist
Common vials: 2 mg, 5 mg, 10 mg
Open calculator
InvestigationalRetatrutide
GIP / GLP-1 / glucagon receptor agonist
Common vials: 5 mg, 10 mg, 20 mg
Open calculator
Not FDA-approvedBPC-157
Synthetic peptide
Common vials: 5 mg, 10 mg
Open calculator
Not FDA-approvedTB-500
Synthetic thymosin β-4 fragment
Common vials: 2 mg, 5 mg, 10 mg
Open calculator
Not FDA-approvedCJC-1295 / Ipamorelin
Growth-hormone secretagogue blend
Common vials: 5 mg, 10 mg
Open calculator
FDA-approved (brand)Tesamorelin
Growth hormone–releasing hormone analog
Common vials: 2 mg, 5 mg, 10 mg
Open calculator
Not FDA-approvedNAD+
Coenzyme (often sold alongside peptides)
Common vials: 100 mg, 500 mg, 1000 mg
Open calculator
How to mix
How to reconstitute a peptide vial in 5 steps
- 01
Clean
Wash your hands. Wipe the rubber tops of the peptide vial and the bacteriostatic water with an alcohol swab and let them air-dry.
- 02
Draw the water
With a new syringe, draw the amount of bacteriostatic water — the same number you entered in the calculator. Use several draws if it’s more than your syringe holds.
- 03
Add it slowly
Insert the needle at an angle and let the water run down the inside wall of the vial, not straight onto the powder.
- 04
Swirl, don’t shake
Gently swirl or roll the vial until the powder dissolves completely. The liquid should look clear.
- 05
Label & refrigerate
Write the date and concentration on the vial and keep it in the fridge.
Coming soon
Your dose, remembered.
Log injection days, see how much is left in your vial, and get a gentle reminder when the next dose is due.
Please read before injecting
Always confirm your dose, concentration and syringe markings with your prescriber or pharmacist. Small calculation errors can have serious consequences. This tool does math — it doesn’t tell you what dose to take.
Good to know
Frequently asked questions
What does “units” mean on an insulin syringe?
U-100 insulin syringes are marked in units of volume: 100 units = 1 mL, so 10 units = 0.1 mL. Units tell you how much liquid to draw, not how much medication — that depends on the concentration of your vial.
How much bacteriostatic water should I add?
Any amount works as long as you enter the same number in the calculator. More water gives a lower concentration, so each dose takes more units — easier to measure small doses, but more liquid per injection.
Which syringe size should I use?
1 mL syringes hold 100 units and are usually marked every 2 units. 0.5 mL (50 units) and 0.3 mL (30 units) syringes are marked every unit, which makes small doses easier to read accurately.
My dose is more than the syringe holds — what now?
You can split it into two draws, use a larger syringe, or mix your next vial with less water so the same dose takes fewer units. The calculator flags this for you.
How long does a reconstituted vial last?
Follow the beyond-use date on your pharmacy label. Keep the vial refrigerated, don’t freeze it, and discard it if the liquid looks cloudy.
Is this medical advice?
No. This is an educational calculator that converts the dose you enter into syringe units. Your prescriber or pharmacist decides your dose.