Peptide Guide
Last updated: May 2026
BPC-157 Peptide Guide
This guide covers how to reconstitute a BPC-157 vial with bacteriostatic water, calculate the correct draw volume in mL and U-100 units from your dose in mcg, and prepare subcutaneous injections. It is a mathematical and procedural reference — not medical advice.
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What is BPC-157?
BPC-157 (Body Protective Compound-157) is a synthetic pentadecapeptide derived from a protein found in gastric juice. It is used in research contexts. BPC-157 is supplied as a lyophilised (freeze-dried) white powder in sealed vials, typically in 5 mg or 10 mg sizes. The powder must be reconstituted by dissolving it in bacteriostatic water before use — it is not sold as a ready-to-inject solution.
BPC-157 vials are not FDA-approved for human use. They are sold for research purposes.
Understanding vial size and dose units
A critical source of confusion is the difference between how vials are labelled and how doses are expressed:
- Vial label: typically in milligrams (mg) — e.g., "5 mg" or "10 mg"
- Individual doses: typically in micrograms (mcg)
- Conversion: 1 mg = 1,000 mcg
A 5 mg vial contains 5,000 mcg total. A dose of 250 mcg uses 5% of that vial. The BPC-157 calculator handles this conversion — you enter the vial size in mg and the dose in mcg, and it handles the arithmetic internally.
Reconstitution: adding BAC water
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol, which prevents bacterial growth and extends the shelf life of reconstituted solutions. It is the standard diluent for peptide reconstitution.
The amount of BAC water you add determines your vial concentration:
Concentration formula
Concentration (mcg/mL) = Vial content (mcg) ÷ BAC water added (mL)
| BAC water | 5 mg vial (5,000 mcg) | 10 mg vial (10,000 mcg) |
|---|
| 1 mL | 5,000 mcg/mL | 10,000 mcg/mL |
| 2 mL | 2,500 mcg/mL | 5,000 mcg/mL |
| 3 mL | 1,667 mcg/mL | 3,333 mcg/mL |
| 5 mL | 1,000 mcg/mL | 2,000 mcg/mL |
More BAC water = lower concentration = larger draw volume per dose. Keep draws above 0.05 mL (5 units) for reliable measurement. Adding 2 mL to a 5 mg vial at a 250 mcg dose gives 0.10 mL — 10 units, easy to read on a standard insulin syringe.
Reconstitution step-by-step
- Allow vials to reach room temperature before opening.
- Wipe the BPC-157 vial septum and the BAC water vial septum with separate alcohol swabs. Allow 10–15 seconds to dry.
- Draw your chosen BAC water volume into a syringe (e.g., 2 mL for a 5 mg vial).
- Insert the needle into the BPC-157 vial and slowly inject water down the side of the vial — not directly onto the powder. This prevents foaming and degradation.
- Gently swirl the vial until the powder fully dissolves. Do not shake or vortex.
- The reconstituted solution should be clear and colourless. Discard if cloudy, discoloured, or particulate.
Calculating draw volume
Example — 250 mcg dose, 5 mg vial, 2 mL BAC water
Concentration: 5,000 ÷ 2 = 2,500 mcg/mL
Draw = 250 ÷ 2,500 = 0.10 mL
= 10 units on a U-100 syringe
Get your exact draw volume and U-100 units from any BPC-157 vial size, BAC water volume, and dose.
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Storage after reconstitution
Once reconstituted, store the vial in the refrigerator (2–8°C / 36–46°F). Do not freeze a reconstituted vial — freezing can degrade the peptide. Bacteriostatic water's preservative properties typically keep reconstituted solutions stable for 4–6 weeks refrigerated. Protect from light. Check the solution visually before each draw — discard if any cloudiness or particles appear.
Unreconstituted vials (sealed powder) may tolerate longer storage — follow the supplier's guidance and note the expiry date on the vial label.
Frequently asked questions
What is BPC-157 and what does it come in?
BPC-157 (Body Protective Compound-157) is a synthetic pentadecapeptide derived from a protective protein found in gastric juice. It is used in research contexts and is supplied as a lyophilised (freeze-dried) powder in sealed vials, typically in 5 mg or 10 mg sizes. Before it can be injected, the powder must be reconstituted by adding bacteriostatic water. It is not supplied as a pre-mixed solution. BPC-157 vials are sold for research purposes and are not FDA-approved for human use.
How much BAC water should I add to a BPC-157 vial?
There is no single correct amount — the volume of BAC water you add determines the concentration of your reconstituted vial. More water means lower concentration and larger draw volumes per dose; less water means higher concentration and smaller draws. For a 5 mg (5,000 mcg) vial, adding 1 mL gives 5,000 mcg/mL while adding 2 mL gives 2,500 mcg/mL. Common practice is to add 1–3 mL. The goal is to keep per-dose draw volumes between 0.05–0.50 mL for accurate measurement on a standard insulin syringe. Use the BPC-157 calculator to find the draw volume for any BAC water and dose combination.
How do I calculate my BPC-157 dose in mL?
Step 1: Calculate vial concentration by dividing total vial content in mcg by the mL of BAC water added. Example: 5,000 mcg ÷ 2 mL = 2,500 mcg/mL. Step 2: Divide your intended dose in mcg by the concentration. Example: 250 mcg ÷ 2,500 mcg/mL = 0.10 mL. Step 3: Multiply by 100 to get U-100 insulin syringe units: 0.10 mL × 100 = 10 units. The InjectBuddy BPC-157 calculator performs all three steps automatically.
How should reconstituted BPC-157 be stored?
Unreconstituted BPC-157 powder should be stored frozen or refrigerated and protected from light. Once reconstituted with BAC water, the solution should be kept refrigerated at 2–8°C (36–46°F). Bacteriostatic water contains benzyl alcohol as a preservative, which extends the stability of reconstituted peptide solutions compared to plain sterile water. Reconstituted vials are generally considered stable for 4–6 weeks refrigerated, though this depends on the specific product and storage conditions. Never freeze a reconstituted vial. Always check for visible cloudiness or particles before drawing — discard if present.
Can I use regular sterile water instead of bacteriostatic water to reconstitute BPC-157?
Bacteriostatic water (BAC water) contains 0.9% benzyl alcohol as a preservative, which prevents bacterial growth in the vial after it has been opened and punctured multiple times. Sterile water does not contain benzyl alcohol — once opened, it offers no protection against contamination during repeated draws. Because a reconstituted peptide vial is typically used over several weeks, bacteriostatic water is the appropriate diluent. Do not use plain sterile water for multi-dose preparations. Use the BPC-157 calculator to confirm your concentration and draw volumes once reconstituted.
Sources
BPC-157 research is primarily preclinical, conducted in rodent models. Human clinical trials are limited. The available evidence covers gastrointestinal, musculoskeletal, and wound-healing outcomes in animal models. BPC-157 is not FDA-approved for human use and is sold as a research compound. The reconstitution and injection preparation information in this guide is based on standard peptide handling practices, not specific BPC-157 clinical data.
Sikiric P, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Curr Pharm Des. 2011;17(16):1612–1632. ·
Chang CH, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol. 2011;110(3):774–780.
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