Free peptide calculator

Peptide reconstitution & dosage calculator

Calculate BAC water volume, mg/mL concentration and insulin syringe units for any peptide vial. Then track every dose, set reminders and check interactions inside DoseRoutine.

7-day free trial. Cancel anytime. No credit card required to start.

Peptide dose calculator

Concentration

2.500 mg/mL

Volume per dose

0.100 mL

Syringe units

10.0 units

Doses per vial

20.0

This calculator is for educational purposes only. Always verify doses with your prescribing clinician and follow sterile reconstitution practices.

Why use DoseRoutine for peptide dosing?

A calculator gets the math right. DoseRoutine keeps the whole protocol on track.

Instant reconstitution math

Enter vial milligrams and BAC water volume. See mg/mL, mL per dose and insulin units in one tap.

U-100 & U-40 syringes

Switch between common insulin syringe types so your draw matches the needle you actually own.

Peptide presets

Start faster with BPC-157, TB-500, semaglutide, tirzepatide, ipamorelin and CJC-1295 presets.

Track every dose

Download DoseRoutine to log each injection, set reminders and never miss a scheduled dose.

Interaction checks

See how peptides, supplements and medications interact before you combine them in one stack.

Vial inventory

Know exactly how many doses remain and when to reorder so you never run out mid-cycle.

How peptide reconstitution works

1

Add BAC water

Inject bacteriostatic water slowly down the inside of the vial. Do not shake — swirl gently until the powder dissolves.

2

Find concentration

Divide the peptide milligrams by the BAC water milliliters. Example: 5 mg ÷ 2 mL = 2.5 mg/mL.

3

Draw your dose

Use the calculator to convert your target dose into mL and insulin syringe units. Log each dose in DoseRoutine.

Stop guessing peptide doses

Join thousands tracking peptides, supplements and medications in one clean daily routine. Start your 7-day free trial today.

Frequently asked questions

What is peptide reconstitution?Copy link

Peptide reconstitution means mixing freeze-dried peptide powder with bacteriostatic water so it becomes a liquid you can draw into a syringe. The amount of water you add changes the concentration, which is why dose calculations matter.

How much bacteriostatic water should I add to a 5mg peptide vial?Copy link

A common starting point is 2 mL of BAC water per 5 mg of peptide. This gives 2.5 mg/mL, or 2500 mcg/mL. Add 1 mL for a stronger 5 mg/mL mix, or 3 mL for a gentler 1.67 mg/mL mix. Use the calculator above to try any volume and see the exact units to draw.

How much bacteriostatic water for a 10mg peptide vial?Copy link

2 mL of BAC water in a 10 mg vial gives 5 mg/mL (5000 mcg/mL). A 250 mcg dose is 0.05 mL, or 5 units on a U-100 insulin syringe. Many people use 2 mL for BPC-157, TB-500 and Ipamorelin 10 mg vials because the math is clean.

How do I convert my peptide dose to insulin syringe units?Copy link

Find your concentration in mg/mL, divide your target dose by that concentration to get mL, then multiply by 100 for a U-100 insulin syringe (or by 40 for a U-40 syringe). Example: 0.25 mg ÷ 2.5 mg/mL = 0.1 mL = 10 units on U-100.

How many doses are in a peptide vial?Copy link

Divide the total vial milligrams by your dose in milligrams. A 5 mg vial at 0.25 mg per dose gives 20 doses. A 10 mg vial at the same dose gives 40 doses. The calculator above shows this automatically.

How do I calculate a semaglutide dose in units?Copy link

Semaglutide is dosed in milligrams but drawn in units. If a 5 mg vial is reconstituted with 2 mL of BAC water, that is 2.5 mg/mL. A 0.25 mg starting dose = 0.1 mL = 10 units on a U-100 insulin syringe. A 0.5 mg dose = 20 units. A 1 mg dose = 40 units.

How do I calculate a tirzepatide dose in units?Copy link

For a 10 mg tirzepatide vial reconstituted with 2 mL of BAC water (5 mg/mL): a 2.5 mg starting dose = 0.5 mL = 50 units on a U-100 insulin syringe. A 5 mg dose = 100 units (a full 1 mL insulin syringe). Many users split into two smaller draws for higher doses.

What is the correct BPC-157 dosage?Copy link

Common research-cited BPC-157 doses range from 200 to 500 mcg per day. With a 5 mg vial reconstituted in 2 mL of BAC water (2.5 mg/mL), 250 mcg = 0.1 mL = 10 units on a U-100 syringe. Always follow guidance from a licensed clinician.

How do I dose TB-500 (thymosin beta-4)?Copy link

Research protocols commonly cite 2–2.5 mg of TB-500 twice weekly during a loading phase, then a maintenance dose. A 5 mg vial in 2 mL BAC water (2.5 mg/mL) means 2.5 mg = 1 mL = 100 units on a U-100 syringe.

How do I calculate an Ipamorelin dose?Copy link

Typical Ipamorelin protocols use 200–300 mcg per injection, 1–3 times daily. With a 5 mg vial in 2 mL of BAC water (2.5 mg/mL), 300 mcg = 0.12 mL = 12 units on a U-100 insulin syringe.

What is the difference between a U-100 and U-40 insulin syringe?Copy link

A U-100 syringe has 100 units per mL. A U-40 syringe has 40 units per mL. If you use a U-40 syringe with a U-100 concentration you will under-dose by 60%. Always confirm which syringe you have — the calculator above supports both.

How long does a reconstituted peptide last in the fridge?Copy link

Once mixed with bacteriostatic water, most peptides are considered stable for roughly 28 days refrigerated at 2–8°C (36–46°F). Sensitive peptides like GLP-1s and BPC-157 are often used within 30 days. Keep vials upright, protected from light, and never freeze after reconstitution unless the manufacturer specifies it.

Can I use sterile water instead of bacteriostatic water?Copy link

Sterile water has no preservative, so a reconstituted vial should be used within 24 hours. Bacteriostatic water contains 0.9% benzyl alcohol which inhibits bacterial growth and extends usable life to roughly 28 days refrigerated. Bacteriostatic water is the standard choice for multi-dose peptide vials.

What does a peptide reconstitution calculator do?Copy link

A peptide reconstitution calculator converts a target dose in milligrams or micrograms into the exact volume to draw on an insulin syringe, based on how much bacteriostatic water you added to the vial. It also shows the resulting concentration in mg/mL and how many doses the vial contains.

Do I need to create an account to use this calculator?Copy link

No. The reconstitution and dose calculator on this page runs entirely in your browser and requires no signup. Enter the vial strength, BAC water volume and target dose to get the syringe units instantly.

How can I track peptide injections over time?Copy link

To keep a record of each injection, most people use a dose-tracking app that supports vial inventory, injection site rotation and reminder alarms. That way the calculator handles the math and the tracker handles the schedule and history.

Ready to track your peptide protocol?

DoseRoutine turns reconstitution math, dose reminders, interaction checks and vial inventory into one simple app.

  • Reconstitution + dosage calculators
  • Dose reminders with calendar export
  • Interaction checker for 450+ compounds
  • Vial inventory and refill alerts
  • Doctor-ready reports

Available on iOS and Android. Cancel anytime.

Peptide dosage glossary

Quick definitions for the terms used across peptide reconstitution, syringe unit conversion, and TRT dosing.

Reconstitution
Dissolving a lyophilized (freeze-dried) peptide with bacteriostatic water to make an injectable solution.
Bacteriostatic water (BAC water)
Sterile water with 0.9% benzyl alcohol that inhibits bacterial growth, extending a mixed vial's usable life to ~28 days refrigerated.
Concentration (mg/mL)
Peptide milligrams divided by BAC water milliliters. Drives how many syringe units equal your target dose.
U-100 insulin syringe
Holds 100 units per 1 mL. 1 unit = 0.01 mL. The standard syringe for peptide and TRT subcutaneous dosing.
U-40 insulin syringe
Holds 40 units per 1 mL. 1 unit = 0.025 mL. Less common; using it in place of U-100 changes dose by ~60%.
Subcutaneous (SC)
Injection into the fatty layer under the skin (abdomen, flank, thigh) using a 29–31 gauge, 8 mm insulin needle.
Intramuscular (IM)
Injection into muscle tissue (glute, delt, quad) with a 23–25 gauge, 1 inch needle. Common for TRT esters.
Half-life
Time for blood levels to fall by half. Drives injection frequency — short half-life = more frequent shots.
Ester
Chemical tail attached to testosterone (cypionate, enanthate, propionate) that controls release speed and half-life.
mcg vs mg
1 mg = 1,000 mcg. Peptide doses are often written in mcg; always confirm units before drawing.