How the Peptide Calculators Work

CalcMyPeptide solves peptide reconstitution, dosing, GLP-1 scheduling, and pharmacokinetic decay using verified formulas. The core reconstitution equation is mg/mL = vial_mg ÷ water_mL; dose conversion is units = desired_dose_mcg ÷ mcg_per_unit. All six calculators run client-side in the browser with no data transmission.

Last updated: March 2026

Our calculators cover the full peptide workflow: from reconstitution and dose conversion to GLP-1 scheduling and half-life decay. Here's how each one works:

Reconstitution Calculator

Enter your peptide vial size (mg) and the volume of bacteriostatic water (mL) to calculate the concentration in mg/mL. Then enter your desired dose in micrograms to see exactly how many syringe units to draw.

Formula

Concentration = vial_mg ÷ water_mL
mcg/unit = (vial_mg × 1000) ÷ (water_mL × syringe_units)
units_to_draw = desired_dose_mcg ÷ mcg_per_unit

Example

A 5 mg vial reconstituted with 2 mL BAC water → 2.5 mg/mL concentration. For a 250 mcg dose with a 1.0 mL (100-unit) syringe → 25 mcg/unit → draw 10 units.

Reverse Calculator

Work backwards from a target concentration to find the optimal water volume. Enter your vial size and desired concentration, and the calculator tells you how much bacteriostatic water to add.

Formula

water_mL = vial_mg ÷ target_concentration_mg_per_mL

Example

Want 5 mg/mL from a 10 mg vial → add 2 mL BAC water.

GLP-1 Dose Scheduler

Generate week-by-week dose escalation schedules for semaglutide, tirzepatide, and retatrutide following published clinical protocols. See the exact syringe units for each escalation step.

Formula

Schedule follows FDA-approved dose escalation:
Semaglutide: 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg/week
Tirzepatide: 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg/week

Example

Semaglutide week 5 at 0.5 mg/week from a 5 mg/2 mL vial → 4 units with a 100-unit syringe.

Vial Duration Calculator

Calculate how many days a reconstituted vial will last based on your dosing frequency and amount. Also shows cost per dose when you enter the vial price.

Formula

days = (vial_mg × 1000) ÷ (dose_mcg × doses_per_day)
cost_per_dose = vial_price ÷ total_doses

Example

A 5 mg vial at 250 mcg once daily = 20 days. At $30/vial → $1.50 per dose.

Half-Life Visualizer

Interactive chart showing exponential decay over 5 half-lives for any peptide. Visualize how plasma concentration drops over time to understand optimal dosing frequency.

Formula

C(t) = C₀ × 0.5^(t ÷ t_half)

Example

BPC-157 with a 4-hour half-life: after 8 hours (2 half-lives), 25% of the original dose remains.

Tips for Accurate Calculations

✓Always double-check your vial size — common sizes are 2 mg, 5 mg, and 10 mg.
✓Use only bacteriostatic water (BAC water) for reconstitution, not sterile water.
✓Reconstituted vials should be stored at 2-8°C and used within 28 days.
✓When drawing from the vial, inject the same volume of air first to equalize pressure.
✓You can use decimals in all input fields for precise calculations.
✓All calculations run entirely in your browser — nothing is sent to any server.