Peptide Dosage Calculator: How to Calculate Reconstitution & Doses

Peptide dosing requires a level of precision that many researchers initially find intimidating. Unlike tablets or capsules with pre-measured doses, peptides require you to:

1. Reconstitute a lyophilised powder with a specific volume of water 2. Calculate the resulting concentration 3. Measure the correct volume from that solution

Getting any of these steps wrong can result in doses that are too high (risking side effects) or too low (sub-therapeutic and wasting material). The good news is that the maths is straightforward once you understand the principles.

Key units you'll encounter: - mg (milligrams): 1mg = 1,000mcg. Typically used for the total amount of peptide in a vial - mcg (micrograms): 1mcg = 0.001mg. The standard unit for peptide dosing - ml (millilitres): Volume of liquid. 1ml = 100 units on a standard U-100 insulin syringe - IU (International Units): Used for insulin syringes to mark volume. On a U-100 syringe, 100 IU = 1ml

The critical distinction: The number of "units" on your insulin syringe refers to volume (IU), not dose. The actual peptide dose depends on the concentration you created during reconstitution.

Before reconstituting, note two critical pieces of information:

1. Peptide amount in the vial This is printed on the vial label — typically in milligrams (mg). Common amounts include: - 2mg vials (common for Ipamorelin, GHRP-6) - 5mg vials (common for BPC-157, CJC-1295, TB-500) - 10mg vials (common for BPC-157, TB-500) - 15mg or 30mg vials (some bulk peptides)

2. The amount of water you'll add This is YOUR choice, and it determines the concentration. You can add any reasonable volume of bacteriostatic water, but common choices are: - 1ml — creates a concentrated solution (fewer injections per vial, but harder to measure small doses) - 2ml — good balance of concentration and measurability - 3ml — more dilute, easier to measure small doses accurately

Example: - 5mg vial of BPC-157 - Add 2ml of bacteriostatic water - Concentration = 5mg ÷ 2ml = 2.5mg/ml = 2,500mcg/ml

This means every 1ml (100 units on an insulin syringe) contains 2,500mcg of BPC-157.

The formula is simple:

Concentration (mcg/ml) = Total peptide (mcg) ÷ Volume of water added (ml)

Or equivalently: Concentration (mg/ml) = Total peptide (mg) ÷ Volume of water added (ml)

Worked examples:

Example 1: BPC-157 (5mg vial + 2ml water) - 5mg = 5,000mcg - 5,000mcg ÷ 2ml = 2,500mcg per ml - Per syringe unit (0.01ml): 2,500 ÷ 100 = 25mcg per unit

Example 2: Ipamorelin (2mg vial + 2ml water) - 2mg = 2,000mcg - 2,000mcg ÷ 2ml = 1,000mcg per ml - Per syringe unit: 1,000 ÷ 100 = 10mcg per unit

Example 3: CJC-1295 (5mg vial + 2.5ml water) - 5mg = 5,000mcg - 5,000mcg ÷ 2.5ml = 2,000mcg per ml - Per syringe unit: 2,000 ÷ 100 = 20mcg per unit

Example 4: TB-500 (5mg vial + 1ml water) - 5mg = 5,000mcg - 5,000mcg ÷ 1ml = 5,000mcg per ml - Per syringe unit: 5,000 ÷ 100 = 50mcg per unit

Pro tip: Choose your water volume to create convenient per-unit concentrations. Adding 2ml to a 5mg vial gives 25mcg per unit — much easier to calculate doses than an awkward number like 33.3mcg per unit.

Once you know the concentration, calculate how much solution you need to draw for your desired dose:

Volume to draw (ml) = Desired dose (mcg) ÷ Concentration (mcg/ml)

Or in syringe units: Units to draw = Desired dose (mcg) ÷ mcg per unit

Worked examples:

Example 1: 250mcg of BPC-157 (concentration: 2,500mcg/ml) - 250 ÷ 2,500 = 0.1ml = 10 units on insulin syringe

Example 2: 300mcg of Ipamorelin (concentration: 1,000mcg/ml) - 300 ÷ 1,000 = 0.3ml = 30 units on insulin syringe

Example 3: 100mcg of CJC-1295 (concentration: 2,000mcg/ml) - 100 ÷ 2,000 = 0.05ml = 5 units on insulin syringe

Example 4: 2mg (2,000mcg) of TB-500 (concentration: 5,000mcg/ml) - 2,000 ÷ 5,000 = 0.4ml = 40 units on insulin syringe

Quick reference table for a 5mg vial reconstituted with 2ml water (2,500mcg/ml):

| Desired Dose | Volume | Syringe Units | |---|---|---| | 100mcg | 0.04ml | 4 units | | 250mcg | 0.10ml | 10 units | | 500mcg | 0.20ml | 20 units | | 750mcg | 0.30ml | 30 units | | 1,000mcg (1mg) | 0.40ml | 40 units |

Insulin syringes are the standard tool for measuring peptide doses. Understanding the markings is essential:

U-100 insulin syringes (most common): - 1ml (100 unit) syringe: Marked in 2-unit increments. Each small line = 2 units = 0.02ml - 0.5ml (50 unit) syringe: Marked in 1-unit increments. More precise for small doses - 0.3ml (30 unit) syringe: Marked in 1-unit increments. Best precision for micro-doses

Which syringe to use: - For doses requiring >50 units: Use a 1ml (100 unit) syringe - For doses requiring 10–50 units: Use a 0.5ml (50 unit) syringe for better accuracy - For doses requiring <10 units: Use a 0.3ml (30 unit) syringe for maximum precision

Reading the meniscus: - When liquid is drawn into the syringe, it forms a curved surface (meniscus) - Read the measurement from the bottom of the meniscus — the lowest point of the curve - Hold the syringe at eye level for accurate reading

Avoiding air bubbles: - Air bubbles reduce the actual volume of peptide drawn - After drawing your dose, hold the syringe needle-up and gently flick to move bubbles to the top - Push the plunger slightly to expel air, then re-measure to ensure the correct volume - Small bubbles (1–2 units) have minimal impact but should be removed for accuracy

Needle gauge recommendations: - 29 gauge: Standard for subcutaneous, good balance of comfort and flow - 30 gauge: Finer, less painful, but slower to draw - 31 gauge: Finest commonly available, minimal discomfort but very slow draw time

For a fuller comparison of 29G to 32G needles and of syringe sizes, see our guide to the best syringes for peptides.

Knowing how many doses you'll get from each vial helps with budgeting and planning:

Formula: Number of doses = Total peptide in vial (mcg) ÷ Dose per administration (mcg)

Common scenarios:

BPC-157 (5mg vial, 250mcg per dose, twice daily): - 5,000mcg ÷ 250mcg = 20 doses - At 2 doses per day = 10 days per vial - For a 4-week protocol: need approximately 3 vials

Ipamorelin (2mg vial, 200mcg per dose, once daily before bed): - 2,000mcg ÷ 200mcg = 10 doses - At 1 dose per day = 10 days per vial - For an 8-week protocol: need approximately 6 vials

CJC-1295 no DAC (5mg vial, 100mcg per dose, once daily): - 5,000mcg ÷ 100mcg = 50 doses - At 1 dose per day = 50 days per vial - For a 12-week protocol: need approximately 2 vials

TB-500 (5mg vial, 2mg per dose, twice weekly loading, then once weekly maintenance): - Loading phase (4 weeks): 2mg × 2/week × 4 weeks = 16mg = approximately 3 vials - Maintenance (4 weeks): 2mg × 1/week × 4 weeks = 8mg = approximately 2 vials - Total 8-week protocol: approximately 5 vials

Budget tip: Calculate your full protocol cost before starting. Multiply the number of vials needed by the per-vial cost to get total peptide expenditure. This prevents surprise costs mid-protocol.

1. Confusing mg and mcg This is the most dangerous mistake. 1mg = 1,000mcg. A dose of "250" could mean 250mcg (typical BPC-157 dose) or 250mg (a massive overdose). Always specify the unit.

2. Confusing syringe units with mcg "10 units" on a syringe means 0.1ml of solution. The actual peptide dose in those 10 units depends entirely on your reconstitution concentration. 10 units from a concentrated solution contains more peptide than 10 units from a dilute solution.

3. Not accounting for dead space Insulin syringes have a small amount of "dead space" in the needle hub that retains liquid. For very small doses, this can represent a meaningful percentage of the dose. Low dead-space syringes are available and recommended for precision work.

4. Reconstituting with too little water While a concentrated solution uses less volume per dose, it makes accurate measurement of small doses very difficult. If your target dose requires drawing less than 5 units, consider adding more water to increase the volume per dose.

5. Not mixing gently after reconstitution The peptide needs to fully dissolve. Aim the water stream down the inside wall of the vial, then gently swirl (never shake). An incompletely dissolved solution will have inconsistent concentration throughout.

6. Mathematical errors Double-check your calculations, especially when sleep-deprived. Use our Dosage Calculator tool to verify your reconstitution maths before measuring doses.

Pro tip: Write your concentration and dose-per-unit on the vial label after reconstitution. This prevents recalculation errors with every dose.

We've built a free Dosage Calculator tool that handles all the maths for you. Here's how to use it:

1. Enter the total peptide amount in your vial (in mg) 2. Enter the volume of water you plan to add (in ml) 3. Enter your desired dose per injection (in mcg) 4. The calculator automatically shows: - Your concentration (mcg/ml and mg/ml) - Volume to draw per dose (in ml and syringe units) - Number of doses per vial - Days per vial at your dosing frequency

The calculator eliminates arithmetic errors and makes it easy to compare different reconstitution volumes to find the most practical concentration for your needs.

Access the calculator: Navigate to our Tools section and select "Dosage Calculator," or use the link in the site navigation.

Remember: While the calculator handles the maths, it's still your responsibility to ensure you're using the correct peptide, the correct water, sterile technique, and following appropriate research protocols. Our calculator is an educational tool — not medical device software.