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Peptide Calculator

Reconstitution ratios, syringe unit conversions, half-life accumulation curves, and split-dosing comparisons.

⚠️ Research & Educational Use Only. These calculators are provided for informational and research purposes only. They do not constitute medical advice, diagnosis, or treatment recommendations. Peptide dosing involves risk. All calculations should be verified with a licensed healthcare provider before any use. Many compounds referenced here are not approved for human use. Ercle does not endorse or facilitate the purchase or use of any compound.

Enter your vial size and the amount of bacteriostatic water you plan to add. The calculator outputs concentration, draw volume per dose, and insulin syringe units (U-100).

mg
mL
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Concentration (mg/mL)
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Draw volume (mL)
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Syringe units (U-100)
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Doses per vial

Common Reconstitution Reference

Peptide Vial BAC Water Concentration Typical Dose
BPC-157 5 mg 2 mL 2.5 mg/mL 250–500 mcg/day
TB-500 5 mg 1 mL 5 mg/mL 2–2.5 mg 2×/wk
CJC-1295 (no DAC) 5 mg 2 mL 2.5 mg/mL 100–300 mcg
Ipamorelin 5 mg 2 mL 2.5 mg/mL 200–300 mcg
Semaglutide 5 mg 2 mL 2.5 mg/mL 0.25–2.4 mg/wk
Tirzepatide 5 mg 2 mL 2.5 mg/mL 2.5–15 mg/wk
Tesamorelin 5 mg 2.5 mL 2 mg/mL 1–2 mg/day
PT-141 10 mg 3 mL 3.3 mg/mL 0.5–1.75 mg
GHK-Cu 50 mg 3 mL 16.7 mg/mL 1–2 mg/day
Sermorelin 3 mg 3 mL 1 mg/mL 0.1–0.3 mg/day
Retatrutide 10 mg 2 mL 5 mg/mL 1–12 mg/wk
AOD-9604 5 mg 2 mL 2.5 mg/mL 250–500 mcg/day

Reference values from published literature and Phase 2/3 trial protocols. Individual compounding may vary. Always verify with your pharmacy.

For peptides with long half-lives like semaglutide and tirzepatide, drug levels accumulate over several weeks before reaching steady state. This chart shows exactly what's happening to circulating levels over your dosing schedule.

mg
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Steady-state peak
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Steady-state trough
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Weeks to steady state
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Accumulation ratio

Drug Level Over Time

Peak level Trough Steady state

Theoretical first-order PK model. Actual blood levels depend on bioavailability, Vd, individual metabolism, and formulation.

Splitting a weekly GLP-1 dose across multiple injections can reduce peak-related side effects (particularly nausea) while maintaining consistent blood levels. Compare dosing schedules side by side.

mg / week

Steady-State Level Comparison (Week 8+)

One representative dosing cycle at steady state. Lower peak = fewer GI side effects; higher trough = more consistent drug exposure.

Why split dosing matters: For semaglutide (t½ ≈ 7 days), a weekly injection builds toward a peak that's ~30% higher than the trough. Splitting into 2–3 injections reduces peak height, which correlates with reduced nausea — the most common reason for discontinuation. The total weekly drug exposure (AUC) remains the same.

Syringe Unit Reference (U-100 Insulin Syringe)

On a standard U-100 insulin syringe, 100 units = 1 mL. Use this chart to quickly cross-reference doses at common concentrations.

Dose @ 1 mg/mL @ 2.5 mg/mL @ 5 mg/mL @ 10 mg/mL
50 mcg 5 units 2 units 1 unit 0.5 units
100 mcg 10 units 4 units 2 units 1 unit
250 mcg 25 units 10 units 5 units 2.5 units
500 mcg 50 units 20 units 10 units 5 units
1 mg 100 units 40 units 20 units 10 units
2 mg overflow 80 units 40 units 20 units
2.5 mg overflow 100 units 50 units 25 units
5 mg overflow overflow 100 units 50 units

"Overflow" = exceeds standard 1 mL syringe capacity. Use more BAC water to dilute, or use a larger syringe.

Disclaimer: These calculators are mathematical tools based on published pharmacokinetic parameters and standard reconstitution mathematics. They do not account for individual variation in drug absorption, distribution, metabolism, or elimination. Results should not be used to self-administer any compound. Many compounds referenced on this page are not approved for human use by the FDA or equivalent regulatory agencies. Always consult a licensed healthcare provider before use. Ercle assumes no liability for use of information provided by these tools.