How does the peptide dosing calculator work?

Enter your vial size (in mg), the amount of BAC water you added (in mL), and your desired dose (in mcg or mg). The calculator instantly computes the concentration (mcg/mL), the exact volume to inject, and how many units to draw on a 1mL/100-unit insulin syringe. It also shows doses per vial and days supply at your chosen frequency.

What is BAC water and why do I use it for reconstitution?

BAC water (bacteriostatic water) contains 0.9% benzyl alcohol, which acts as a preservative. It extends the shelf life of reconstituted peptides to 60–90 days when refrigerated. Plain sterile water works for immediate use only. BAC water is the standard choice for peptide reconstitution in a research setting.

How many units do I draw for a 500mcg BPC-157 dose from a 10mg vial?

With a 10mg vial reconstituted with 3mL BAC water: Concentration = (10 × 1000) / 3 = 3,333mcg/mL. For 500mcg: Volume = 500 / 3,333 = 0.15mL = 15 units on an insulin syringe. Use our calculator to auto-fill these values — just select BPC-157 10mg from the dropdown.

How long do reconstituted peptides last in the fridge?

Reconstituted peptides stored in bacteriostatic water last 60–90 days refrigerated at 2–8°C. Never freeze reconstituted peptides — it damages the protein structure. Unopened lyophilized (powder) peptides can last 1–2 years when stored frozen at -20°C.

What needle size should I use for peptide injections?

For subcutaneous (SubQ) injections: 31 gauge × 8mm (5/16") insulin needle. Pinch belly or love handle fat and insert at 45°. For intramuscular (IM): 25 gauge × 1" for glutes, 27 gauge × 0.5" for delts. Most peptides are given SubQ — shorter needles, less discomfort, and equally effective.

Can I stack multiple peptides together?

Yes — many peptides are synergistic. Classic stacks include BPC-157 + TB-500 for healing, Ipamorelin + CJC-1295 for GH stimulation, and GHK-Cu + BPC-157 for tissue repair. Avoid combining SS-31 with HGH gels, and don't mix Zinc Thymulin with GHK-Cu topically (interference). See our stacking guide for more.

Are peptides safe for women?

Many peptides are well-tolerated by women, but dosing is typically 50–75% of male protocols. GLP-1 peptides (semaglutide, tirzepatide), PT-141, BPC-157, GHK-Cu, and Tesamorelin/Ipamorelin combos are commonly researched in women. Avoid all peptides during pregnancy and breastfeeding — no safety data exists. See our women's peptide guide for protocol suggestions.

Is this calculator free to use?

Yes, completely free. PeptideCalculator.us provides all dosing calculators, reconstitution guides, and the AI research assistant at no cost. All content is for educational and research purposes only.

Free peptide dosing calculator

Peptide Calculator —
Accurate Dosing Made Simple

Calculate reconstitution, dosing, and injection volumes for any peptide. Plus get instant answers to your peptide research questions.

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How It Works

Three steps from vial to injection. No math required.

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Select Your Peptide

Search 70+ peptides in the dropdown. Auto-fills vial size, BAC water amount, and typical dose range.

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Enter Vial & Water

Input your vial size in mg and BAC water added in mL. Or use your custom amounts.

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Get Your Dose

Instantly see units to draw on an insulin syringe, doses per vial, and days supply at your frequency.

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70+ peptides pre-loaded. Works on mobile. Animated syringe visual.

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Peptide Research Guides

In-depth research summaries for every peptide category. Mechanisms, protocols, stacking, and cautions.

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Healing & Repair

Injury recovery, tissue regeneration, anti-inflammatory

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Weight Loss

GLP-1 agonists, metabolic enhancers, appetite modulation

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GH Secretagogues

Growth hormone stimulation, body composition, recovery

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Cellular longevity, mitochondrial health, telomere support

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Nootropic peptides, focus, neuroprotection

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Immune Support

Immunomodulation, antimicrobial, viral defense

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Libido, arousal, fertility support

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Sleep

Sleep quality, circadian rhythm, deep sleep enhancement

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Lean mass, IGF, satellite cell activation

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Tanning

Melanocyte stimulation, UV-independent tanning

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Got a Question?

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Frequently Asked Questions

Common questions about peptide dosing, reconstitution, and this calculator.

PeptideCalculator.us is for educational and research purposes only. All content, calculators, and AI responses are not medical advice. Peptides discussed have not been evaluated by the FDA for the purposes described. Consult a licensed healthcare professional before beginning any peptide research protocol.

Peptide Calculator —Accurate Dosing Made Simple