The Definitive Peptide
Calculator Suite
CalcMyPeptide is a free, browser-based peptide reconstitution and dosing calculator suite covering 25+ research peptides including BPC-157, semaglutide, tirzepatide, and ipamorelin. The core formula — mg/mL = vial_mg ÷ water_mL — converts any lyophilized peptide vial into an exact insulin-syringe unit draw, with all math performed client-side so no data ever leaves your device.
Last updated: March 2026
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Koncentration
—mg/mL
mcg per Enhet
—mcg/unit
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—enheter
How It Works
- 1
Enter your peptide details
Select your peptide, enter the vial size in mg, and the amount of bacteriostatic water you added in mL.
- 2
Choose your syringe
Select your insulin syringe size (0.3 mL, 0.5 mL, or 1.0 mL). CalcMyPeptide calculates the exact concentration and mcg per unit.
- 3
Get your results instantly
See the concentration, micrograms per unit, and exactly how many units to draw — all calculated client-side.
Key Formulas
Concentration
mg/mL = vial_mg ÷ water_mL
Micrograms/Unit
mcg/unit = (vial_mg × 1000) ÷ (water_mL × syringe_units)
Units to Draw
units = desired_dose_mcg ÷ mcg_per_unit
Half-Life Decay
C(t) = C₀ × 0.5^(t ÷ t_half)
Vial Duration
days = (vial_mg × 1000) ÷ (daily_dose_mcg × doses_per_day)
Cost per Dose
cost = vial_price ÷ ((vial_mg × 1000) ÷ dose_mcg)
Frequently Asked Questions
Is CalcMyPeptide free?
Does CalcMyPeptide store my data?
How many peptides does CalcMyPeptide support?
Can I use sterile water instead of bacteriostatic water?
How long do reconstituted peptides last?
What syringe size is best for peptides?
How Many Units of BPC-157 on a 30-Unit Syringe?
On a U-100, 30-unit (0.3 mL) insulin syringe, each unit equals 0.01 mL. If you reconstitute a 5 mg BPC-157 vial with 2 mL bacteriostatic water, the concentration is 2.5 mg/mL = 2,500 mcg/mL. Each unit on the syringe then delivers 25 mcg (2,500 ÷ 100). For a standard 250 mcg research dose: draw 10 units. For 500 mcg: draw 20 units. CalcMyPeptide's Reconstitution Calculator handles any vial size and concentration instantly.
units_to_draw = dose_mcg ÷ (vial_mg × 1000 ÷ (water_mL × syringe_units))
Example: 250 mcg ÷ 25 mcg/unit = 10 units
How Much Bacteriostatic Water for a 5 mg Semaglutide Vial?
For a 5 mg semaglutide vial, the most common protocol adds 1 mL bacteriostatic water, yielding 5 mg/mL. A 0.25 mg weekly starter dose then requires drawing 5 units on a U-100 syringe (0.05 mL). Adding 2 mL instead gives 2.5 mg/mL — useful for users on lower doses who want finer graduation. Bacteriostatic water (0.9% benzyl alcohol) is required — not sterile water — because it provides the 28-day multi-dose window (USP General Chapter 797). See our Bacteriostatic Water Guide for sourcing and storage details.
Semaglutide vs Tirzepatide: Which Has More Weight Loss?
In head-to-head clinical data, tirzepatide (Mounjaro/Zepbound) outperforms semaglutide (Ozempic/Wegovy) for weight loss. The SURMOUNT-5 trial (2025) showed tirzepatide 15 mg achieved 20.2% body weight loss vs 13.7% for semaglutide 2.4 mg over 72 weeks. Tirzepatide's advantage comes from its dual GLP-1/GIP mechanism — it activates GIP receptors that semaglutide (GLP-1 only) does not. CalcMyPeptide's GLP-1 Scheduler generates weekly dose escalation timelines and injection unit calculations for both agents.
What Is the GLOW Peptide Stack?
The GLOW stack is a three-peptide regenerative protocol combining GHK-Cu (copper peptide: collagen/elastin synthesis), BPC-157 (VEGF upregulation, angiogenesis), and TB-500 (Thymosin Beta-4 fragment: systemic cell migration via actin polymerization). The KLOW variant adds a fourth peptide — KPV (Lysine-Proline-Valine: anti-inflammatory via NF-κB inhibition) — to the GLOW base. Use our Blend/Stack Calculator for preset GLOW and KLOW configurations with exact syringe unit outputs. For a full breakdown, see the Wolverine Stack Guide.
How Long Does a Reconstituted Peptide Vial Last?
A peptide vial reconstituted with bacteriostatic water has a beyond-use date of 28 days when stored at 2–8°C (USP General Chapter 797). This applies regardless of remaining dose volume. Lyophilized (freeze-dried) peptide powder remains stable for 12–24 months at −20°C, but once reconstituted, the 28-day clock starts. Never freeze a reconstituted vial — ice crystal formation can denature peptide chains. Use CalcMyPeptide's Vial Duration Calculator to see exactly how many doses remain and the cost per dose for any protocol.
Understanding Peptide Reconstitution Math: Worked Examples
Example 1: BPC-157, 250 mcg/day, 5 mg vial
5 mg vial + 2 mL BAC water → 2.5 mg/mL = 2,500 mcg/mL. On a 100-unit (1.0 mL) syringe: 25 mcg/unit. Draw 10 units per injection. Vial lasts 20 days at one injection/day.
Example 2: Semaglutide, 0.5 mg/week, 5 mg vial
5 mg vial + 2 mL BAC water → 2.5 mg/mL. Weekly dose 0.5 mg = 500 mcg = 0.2 mL. On a 100-unit syringe: 20 units. Vial contains 10 weekly doses at 0.5 mg.
Example 3: Ipamorelin + CJC-1295 blend, each at 200 mcg/dose
2 mg ipamorelin + 2 mg CJC-1295 (no DAC), each in 2 mL BAC water → 1 mg/mL = 1,000 mcg/mL per peptide. On a 30-unit (0.3 mL) syringe: 10 mcg/unit. Draw 20 units of each for 200 mcg dose.