Free research tool
Peptide Calculator
Get the exact syringe units to draw for any peptide dose. Dosage, reconstitution, and blend — all in one place.
Works for BPC-157, tirzepatide, semaglutide, and any other peptide
Three calculators — dosage, reconstitution, and blend
Visual syringe guide shows exactly where to stop the plunger
Built by a BSc Biotechnology graduate — formulas verified
100%
free — no account
or signup needed
or signup needed
3
calculator types:
dose, recon, blend
dose, recon, blend
Any
peptide — works for
all BAC water vials
all BAC water vials
Example — BPC-157, 250mcg from a 5mg / 2mL vial
0100 units
Draw syringe to
10
units · 0.100 mL
Peptide dose
250 mcg
Concentration
2.5 mg/mL
Vial strength
5 mg
Total doses
20 doses
Click any peptide below to pre-fill the dosage calculator instantly.
Peptide Calculators
Three specialised tools in one place. Select the tab that matches your task.
Free dosage tool
Peptide Dosage Calculator
Toggle mcg or mg, select your dose, vial strength, and BAC water volume. Results update instantly.
01
Desired dose
Toggle between mcg and mg. 1mg = 1000mcg.
02
Peptide vial strength
Total milligrams printed on the vial label.
03
Bacteriostatic water added
How much BAC water you added when reconstituting, in mL.
04
Syringe size
Scales the visual guide.
Free reconstitution tool
Peptide Reconstitution Calculator
Enter your vial strength and BAC water volume to get the exact concentration, draw volume, and total doses.
01
Peptide vial strength
Total amount printed on the vial label, in mg.
02
Bacteriostatic water added
Volume of BAC water you inject into the vial, in mL.
03
Desired dose per injection
Most healing peptides use 100–500mcg. Weight loss peptides use mg doses.
04
Syringe size
Scales the visual guide.
Free blend tool
Peptide Blend Calculator
Calculate draw volumes for 2 or 3 peptides blended into one syringe. Each peptide is calculated from its own reconstituted vial.
Peptides in blend:
Peptide 1
Peptide 2
Peptide 3
Syringe size:
Blend resultsCalculated
Combined draw — syringe guide
0100 units
Peptide 1
Peptide 2
Peptide 3
Peptide 1
--
-- mL
Peptide 2
--
-- mL
Peptide 3
--
-- mL
For research purposes only. Not medical advice.
How to Use the Calculator
The dosage calculator needs three inputs: the total peptide in your vial, how much bacteriostatic water you added when reconstituting, and the dose you want per injection.
From those three numbers it calculates concentration, draw volume, and the syringe units — the number you look for on your insulin syringe. On a standard U-100 syringe (1mL / 100 units) each unit equals exactly 0.01mL.
Not reconstituted yet? Switch to the Reconstitution Calculator to find the right BAC water volume first.
1
Select your vial strength
Find the milligrams printed on the vial label — the total peptide in the vial. Common sizes are 5mg and 10mg.
2
Enter your BAC water volume
How many mL of bacteriostatic water did you add? This determines your concentration. A 5mg vial with 2mL gives 2.5mg/mL.
3
Select your dose
Choose the amount per injection. Healing peptides like BPC-157 use 250–500mcg. Weight loss peptides like tirzepatide start at 2.5mg.
4
Read the result
The large number is the syringe units to draw. The syringe graphic fills to match — use it as a visual reference when loading your syringe.
Calculate by Peptide
Click "Calculate" on any peptide to switch to the dosage calculator with the most common values pre-filled. Adjust the BAC water volume to match your vial.
Healing
BPC-157
Body Protection Compound. Studied for tissue repair, gut healing, and joint recovery in preclinical research.
Common dose250–500mcg
Typical vial5mg or 10mg
Weight Loss
Tirzepatide
Dual GIP/GLP-1 receptor agonist. Extensively researched for metabolic function and body weight reduction.
Common dose2.5–15mg
Typical vial10mg or 15mg
Weight Loss
Semaglutide
GLP-1 receptor agonist. Widely researched for appetite regulation, blood glucose control, and weight reduction.
Common dose0.25–2mg
Typical vial3mg or 5mg
Weight Loss
Retatrutide
Triple GIP/GLP-1/glucagon receptor agonist. An emerging compound under active clinical research for metabolic outcomes.
Common dose0.5–4mg
Typical vial10mg
Recovery
TB-500
Thymosin Beta-4 fragment. Frequently studied alongside BPC-157 for its role in muscle repair and systemic recovery.
Common dose2.5–5mg
Typical vial10mg
Longevity
NAD+
Nicotinamide adenine dinucleotide. Central to cellular energy metabolism and DNA repair, studied in ageing research.
Common dose100–500mg
Typical vial500mg or 1g
Growth Hormone
Ipamorelin
A selective GHRP. Studied for its clean growth hormone secretagogue profile without significant cortisol effects.
Common dose200–300mcg
Typical vial5mg
Growth Hormone
CJC-1295
A GHRH analogue. Frequently combined with Ipamorelin to study sustained growth hormone pulse amplitude.
Common dose100–300mcg
Typical vial5mg
What Is a Peptide Calculator?
A peptide calculator converts your desired research dose — in micrograms (mcg) or milligrams (mg) — into the exact volume to draw into a syringe. Without one, you need to perform three unit conversions manually, which is where most dosing errors happen.
The core problem is concentration. When you dissolve a 5mg vial in 2mL of bacteriostatic water you get 2.5mg/mL. With 3mL instead, concentration drops to 1.67mg/mL — and the volume for the same 250mcg dose changes from 0.1mL to 0.15mL. On a 100-unit syringe that is 10 units versus 15 units. This calculator handles it automatically for any combination.
The formulas used are standard pharmaceutical dilution calculations. The panel on the right shows every step so you can verify any result by hand.
Open the dosage calculator →The calculation — step by step
Concentration = Vial strength ÷ BAC water
e.g. 5mg ÷ 2mL = 2.5 mg/mL
Draw volume = Dose ÷ Concentration
e.g. 0.25mg ÷ 2.5mg/mL = 0.1 mL
Syringe units = Draw volume × 100
e.g. 0.1mL × 100 = 10 units on a U-100 syringe
Why U-100 syringes?
U-100 means 100 units per mL. On a 1mL insulin syringe each unit mark equals exactly 0.01mL. The units figure the calculator produces maps directly to the markings on your syringe.
mcg vs mg — quick reference
1mg = 1,000mcg. Peptide doses are often stated in mcg because the amounts are small. A 250mcg dose is the same as 0.25mg. Use the mcg/mg toggle in the dosage calculator.
How to Reconstitute Peptides
Allow the vial to reach room temperature
Remove the peptide vial from the freezer 15–30 minutes before reconstituting. A cold vial creates pressure differences that can cause foaming when water is injected.
Calculate your water volume first
Use the Reconstitution Calculator above to choose your BAC water volume before opening anything. The volume you add determines your concentration for every future dose.
Inject water down the side of the vial
Angle the needle so water runs slowly down the inner glass wall — not directly onto the lyophilised powder. This prevents foaming. Inject slowly over 10–15 seconds.
Swirl gently — never shake
Roll the vial between your palms until fully dissolved. The solution should appear clear and colourless within 30–60 seconds. Shaking can disrupt peptide bonds.
Label the vial immediately
Write the reconstitution date and BAC water volume on the vial. You need both numbers every time you use the calculator. A 5mg vial with 2mL and one with 3mL require completely different draw volumes for the same dose.
⚠ Use BAC water — not sterile water
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth across multiple uses. Sterile water must be discarded within 24–48 hours of opening. For multi-dose peptide vials, BAC water is the correct solvent.
Peptide storage reference
Lyophilised powder (sealed)
Temperature−20°C (freezer)
Shelf life12–24 months
Light sensitivityKeep in original vial
Reconstituted in BAC water
Temperature2–8°C (refrigerator)
Shelf life4–6 weeks
Do not freezeDamages peptide structure
Reconstituted in sterile water
Temperature2–8°C
Shelf life24–48 hours only
ReasonNo preservative
mcg, mg, mL, and Units — What They Mean
Peptide dosing uses four different units that are easy to confuse. Here is a plain-language reference for each one.
| Unit | Full name | What it measures | Example |
|---|---|---|---|
| mg | Milligram | Mass of peptide. Used for vial strength and larger doses. | 5mg vial — total peptide in the vial |
| mcg | Microgram | Mass of peptide. For small doses. 1mg = 1,000mcg. | 250mcg dose = 0.25mg |
| mL | Millilitre | Volume of liquid — BAC water added, or draw volume. | 0.1mL draw — volume you pull into the syringe |
| Units | Insulin syringe units | Graduation marks on a U-100 syringe. 100 units = 1mL. | 10 units = 0.1mL on a 1mL / 100-unit syringe |
| mg/mL | Milligrams per millilitre | Concentration of the reconstituted solution. | 2.5mg/mL — 5mg vial in 2mL BAC water |
Quick rules: 1mg = 1,000mcg · 1mL = 100 units on a U-100 syringe · Concentration = vial strength ÷ BAC water volume
Common Peptide Calculations
The most frequently searched peptide dosage questions. Click "Calculate" to open the calculator with the relevant values pre-filled.
250mcg to mL
How many mL is a 250mcg dose? Depends on your concentration.
500mcg to mL
How many mL is a 500mcg dose? Depends on your concentration.
5mg — how many units?
How many syringe units is a 5mg dose?
10mg — how many units?
How many syringe units is a 10mg dose?
mg to mL converter
Convert any peptide dose in mg to draw volume in mL.
Units to mcg converter
Convert syringe units back to micrograms for any concentration.
BPC-157
250mcg — how many units?
Exact syringe units for a 250mcg BPC-157 dose from a 5mg vial.
BPC-157
500mcg — how many units?
Exact syringe units for a 500mcg BPC-157 dose from a 5mg vial.
Tirzepatide
5mg — how many units?
Exact syringe units for a 5mg tirzepatide dose from a 10mg vial.
Tirzepatide
10mg — how many units?
Exact syringe units for a 10mg tirzepatide dose from a 15mg vial.
Semaglutide
1mg — how many units?
Exact syringe units for a 1mg semaglutide dose from a 5mg vial.
Reconstitution
BAC water for a 5mg vial
How much bacteriostatic water should you add to a 5mg vial?
Reconstitution
BAC water for a 10mg vial
How much bacteriostatic water should you add to a 10mg vial?
Frequently Asked Questions
Common questions about using the peptide calculator, reading syringe units, and reconstitution.
It depends on your concentration. With a 5mg vial and 2mL BAC water (2.5mg/mL), 250mcg = 10 units. With 3mL water (1.67mg/mL), 250mcg = 15 units. With a 10mg vial and 2mL water (5mg/mL), 250mcg = 5 units. Enter your specific values in the dosage calculator above for the exact answer.
With a 5mg vial and 2mL BAC water (2.5mg/mL), 500mcg = 20 units. With 3mL water (1.67mg/mL), 500mcg = 30 units. With a 10mg vial and 2mL water (5mg/mL), 500mcg = 10 units. The number changes every time the concentration changes.
There is no fixed rule — the water volume determines your concentration. A common choice for a 5mg vial is 2mL, giving 2.5mg/mL. At this concentration, 250mcg = exactly 10 units on a 100-unit syringe. Use the Reconstitution Calculator tab to find the volume that gives you the most convenient draw for your dose.
The Dosage Calculator answers: "I already reconstituted — how many units do I draw?" The Reconstitution Calculator answers: "How much BAC water do I add, and what concentration will that give me?" Both use the same formula. Switch between them using the tabs above the calculator.
Most peptide researchers use a U-100 insulin syringe in 0.3mL (30 units), 0.5mL (50 units), or 1mL (100 units) sizes. The 1mL / 100-unit syringe is the most versatile and is the default in all three calculators. A needle gauge of 28–31G is typical for subcutaneous administration.
Concentration (mg/mL) tells you how much peptide is dissolved per millilitre of solution. It is the link between your dose and the volume you draw. Change the BAC water volume during reconstitution and you change the concentration — which changes how many syringe units you need for the same dose. Always label your vial with the water volume used.
Yes. Each peptide is reconstituted in its own vial. You then draw from each in sequence into the same syringe. Use the Blend Calculator tab above to calculate draw volumes for each peptide separately, with a colour-coded syringe guide.
Yes — it works for any peptide reconstituted with bacteriostatic water and measured with an insulin syringe. Click "Calculate Tirzepatide" or "Calculate Semaglutide" in the peptide section above to open the dosage calculator with those values pre-filled.
Peptides reconstituted with bacteriostatic water and stored at 2–8°C are generally stable for 4–6 weeks. Lyophilised powder stored at −20°C remains stable for 12–24 months. Do not freeze reconstituted solutions — freezing disrupts peptide structure. Always label your vial with the reconstitution date.
Yes, completely free. No account, no signup, no paywall. All three calculators — dosage, reconstitution, and blend — run entirely in your browser. No data is sent to any server.