How to Reconstitute Peptides
A complete guide to mixing BPC-157, TB-500, and other peptides with bacteriostatic water — including exact amounts, dose calculations, and storage.
By the BPC-157 Stack Editorial Team · Medically reviewed by Prof. Alastair D. Burt, BSc (Hons) MB ChB MD FRCPath
Published January 18, 2026 · Last updated April 27, 2026 · Last reviewed April 27, 2026
Before You Begin
Only use bacteriostatic water — not tap water, saline, or regular sterile water for multi-dose vials. Work in a clean environment. Never reuse syringes.
Equipment Checklist
Equipment Checklist
0/10Check off each item before you begin. Having everything ready prevents mid-procedure mistakes.
Reconstitution Calculator
Enter your vial size, how much bacteriostatic water you plan to add, and your desired dose — the calculator gives you exact syringe markings instantly.
Reconstitution Calculator
Instantly calculate concentration, dose volume, and syringe markings
Common: 250mcg, 500mcg, 1000mcg
How to read IU: On a standard 1mL insulin syringe, 100 IU = 1mL. Draw to the IU mark shown above. Example: 10 IU = 0.1mL = 100μL.
Quick-Reference Steps
Gather Your Supplies
You need: lyophilized peptide vial, bacteriostatic water vial, alcohol swabs, and insulin syringes (29–31 gauge, 1mL). Everything must be sterile. Never reuse syringes.
Tip: Bacteriostatic water (BAC water) is required — not regular sterile water, not saline. BAC water stays sterile for 28 days after opening.
Wipe All Vial Tops
Swab the rubber stopper on both the peptide vial and the bacteriostatic water vial with a fresh alcohol swab. Allow to air dry for 30 seconds. This prevents contamination.
Tip: Use a new swab for each vial. Do not touch the rubber stopper with your fingers after swabbing.
Draw the Bacteriostatic Water
Draw the amount of BAC water you need into a fresh insulin syringe. For a standard 5mg peptide vial, draw 1mL (100 units on a 1mL syringe). See the dosage table below for other amounts.
Tip: More water = lower concentration per unit. Less water = higher concentration. Standard is 1mL per 5mg vial.
Inject Water Into the Peptide Vial
Insert the syringe through the rubber stopper at an angle. Slowly inject the water down the inside wall of the vial — never directly onto the peptide powder. The powder will dissolve gradually.
Tip: Never spray water directly onto the powder — this can damage the peptide structure. Let it run down the glass wall gently.
Dissolve — Do Not Shake
Gently swirl the vial in a circular motion until the powder fully dissolves into a clear solution. This typically takes 30–60 seconds. The solution should be clear and colorless.
Tip: Never shake the vial vigorously — this can denature the peptide. Gentle swirling or rolling between your palms is correct.
Label and Store
Write the reconstitution date on the vial. Store in the refrigerator at 2–8°C. Use within 30 days. For longer storage, freeze at -20°C — the peptide will last 6+ months frozen.
Tip: Keep away from direct light. Do not leave reconstituted peptides at room temperature for extended periods.
Complete 10-Step Reconstitution Protocol
The full detail behind every step — including the why and common pitfalls at each stage.
Gather All Supplies
Having everything within arm's reach before you start prevents mid-procedure scrambling that leads to contamination.
Lay out on a clean surface: lyophilized peptide vial, bacteriostatic water vial, at least 3 insulin syringes (29–31g, 1mL), 4 alcohol swabs, sharps container, labels, and your notes. Ensure your refrigerator space is confirmed clear.
Wash Hands Thoroughly
The single most common cause of contaminated reconstitutions is hand contamination transferred to vials or syringes.
Wash hands for a minimum of 20 seconds with soap and water, focusing on fingertips, between fingers, and under nails. Dry with a clean paper towel. If using gloves, put them on now after drying.
Wipe Vial Tops With Alcohol Swab
Environmental bacteria settle on all surfaces including vial tops. The rubber stopper is porous enough to allow surface contaminants through if not cleaned.
Use a fresh alcohol swab for each vial. Swipe once across the top in a single direction — do not rub back and forth. The single-swipe technique prevents recontaminating the cleaned area. Allow to air dry completely (30 seconds) before piercing.
Draw Air Into Syringe Equal to Water Amount
Drawing air into the syringe first creates positive pressure in the BAC water vial, making it easier to draw the exact amount of water without fighting vacuum.
Pull the plunger back to draw air equal to the volume of water you plan to transfer (e.g., 1mL of air if transferring 1mL of BAC water). This step is optional but simplifies precise drawing.
Inject Air Into the BAC Water Vial
Injecting air first equalizes pressure in the vial, making drawing the water smooth and accurate.
Insert the needle through the cleaned rubber stopper at a slight angle to minimize coring. Push the plunger to inject the air. Keep the needle tip submerged below the liquid level before drawing.
Draw the Calculated Water Amount
Precision here determines your final concentration — even a 0.2mL difference changes your dosing math.
Invert the BAC water vial and draw the exact amount needed. Go slowly — aspirating too fast causes bubbles. If you get bubbles, tap the syringe gently and push small air bubbles back into the vial, then re-draw to the correct mark.
Insert Needle Into Peptide Vial at Angle
Entering at an angle reduces coring of the rubber stopper — tiny rubber particles that can contaminate your solution.
Pierce the cleaned peptide vial stopper at a 45-degree angle, bevel up. Insert just far enough that the needle tip clears the stopper and is inside the vial. Do not insert all the way through to the glass.
Slowly Release Water Down the Inside Wall
Direct injection onto the peptide powder can mechanically disrupt peptide structure. Running water down the glass wall is gentler.
Tilt the vial slightly so the needle tip points toward the inside glass wall. Push the plunger very slowly, allowing water to run down the wall and pool below the powder. This is the most critical technique step — take your time.
Do NOT Shake — Gently Swirl Until Dissolved
Vigorous shaking causes foaming and can denature (unfold and deactivate) the peptide. Gentle swirling provides enough energy to dissolve without damage.
Remove the syringe and stopper it or discard. Hold the vial between two fingers and rotate in gentle circles — do not invert repeatedly or shake. Most peptides dissolve in 30–120 seconds. If after 3 minutes there is still undissolved powder, let it sit for 5 minutes at room temperature or place briefly between palms to warm slightly (for TB-500 specifically).
Label Vial With Date and Concentration
Unlabeled vials become a guessing game. Incorrect concentration assumptions lead to over- or under-dosing.
Write on the label: peptide name, vial size (e.g., 5mg), BAC water added (e.g., 1mL), resulting concentration (e.g., 5,000mcg/mL), and the reconstitution date. Store in refrigerator immediately. Do not leave at room temperature.
Peptide Dose Reference Table
How much to draw from a 1mL insulin syringe for 250mcg or 500mcg doses at different concentrations.
| BAC Water | Vial Size | Concentration | 250mcg dose | 500mcg dose |
|---|---|---|---|---|
| 0.5mL | 2mg | 4,000mcg/mL | 6.25μL (0.6 IU) | 12.5μL (1.25 IU) |
| 1mL | 2mg | 2,000mcg/mL | 12.5μL (1.25 IU) | 25μL (2.5 IU) |
| 1mL | 5mg | 5,000mcg/mL | 50μL (5 IU) | 100μL (10 IU) |
| 2mL | 5mg | 2,500mcg/mL | 100μL (10 IU) | 200μL (20 IU) |
| 1mL | 10mg | 10,000mcg/mL | 25μL (2.5 IU) | 50μL (5 IU) |
| 2mL | 10mg | 5,000mcg/mL | 50μL (5 IU) | 100μL (10 IU) |
IU = units on a 1mL insulin syringe (100 IU = 1mL). μL = microliters.
Peptide-Specific Reconstitution Notes
Each peptide has quirks. Here is what to expect when reconstituting the most common peptides.
| Peptide | Dissolves | Normal Color | Time | Special Notes |
|---|---|---|---|---|
| BPC-157 | Very easy | Clear / colorless | Dissolves in 30–60 sec | None — standard protocol |
| TB-500 | Moderate | Clear / slight tint acceptable | 2–5 minutes | Warming may help dissolution |
| CJC-1295 | Easy | Clear / colorless | 30–90 seconds | None — standard protocol |
| Epithalon | Easy | Clear / colorless | 30–60 seconds | Small vial — use less water |
| GHK-Cu | Easy | Light blue / pale blue-green | 30–60 seconds | Blue color is normal and correct |
| Semaglutide / Tirzepatide | N/A | Clear | Pre-mixed available | Pre-mixed options available |
Storage Troubleshooting
What to do when something looks wrong with your reconstituted peptide — and how to tell normal from problematic.
Cloudy or Milky Solution
Potentially ProblematicCloudiness can indicate: (1) bacterial contamination — discard immediately, (2) peptide precipitation due to pH or temperature shock, (3) incomplete dissolution — try gentle warming. If the solution was clear when first reconstituted and turned cloudy during storage, contamination is the most likely cause. When in doubt, discard.
Unusual Color Changes
Context-DependentNormal: GHK-Cu is naturally blue-green due to the copper ion — this is expected. Slight yellow tint in some peptides is acceptable. Abnormal: brown or orange discoloration in peptides that should be clear, or any solution that darkens significantly over time in the refrigerator. Oxidative degradation can cause color changes in certain peptide sequences.
How to Tell if a Peptide Has Degraded
Watch for These SignsSigns of degradation: visible particulate matter that does not dissolve, significant discoloration, unusual smell (peptides should be essentially odorless), reduced effectiveness (anecdotal but a real signal). Peptides degrade faster when: exposed to heat (above 8°C for extended periods), exposed to UV light, stored in non-BAC water, or repeatedly frozen and thawed.
Accidentally Froze Reconstituted Peptide
Usually RecoverableA single freeze-thaw cycle is unlikely to destroy the peptide — most peptides tolerate one accidental freeze reasonably well. Thaw slowly in the refrigerator (not at room temperature). Do not refreeze again — use it within a few days. The main risk is ice crystal formation disrupting the peptide structure, but the BAC water preservative remains effective after thawing.
Temperature Fluctuation Tolerance
Know the LimitsReconstituted peptides are relatively stable between 2–8°C but sensitive to extremes. Brief excursions to room temperature (20–22°C) during dose drawing are fine. Avoid: leaving vials out for more than 30 minutes, refrigerator door shelves where temperature fluctuates with door opening, areas near heating vents or direct sunlight. Maximum tolerable temperature for short periods: approximately 25°C. Above this, degradation accelerates significantly.
Reconstitution FAQ
How much bacteriostatic water do I add to BPC-157?+
The most common approach: add 1mL of bacteriostatic water to a 5mg BPC-157 vial. This creates a concentration of 5,000mcg/mL. For a 250mcg dose, draw 50μL (5 IU on a 1mL insulin syringe). For a 500mcg dose, draw 100μL (10 IU). You can use more water for a lower concentration if you prefer smaller volumes.
Can I use regular sterile water instead of bacteriostatic water?+
Technically you can use regular sterile water, but only if you use the entire vial in a single session — regular sterile water has no preservative and will allow bacterial growth once opened. Bacteriostatic water (0.9% benzyl alcohol) maintains sterility for 28 days and is the correct choice for any multi-dose peptide vial.
How long does reconstituted BPC-157 last in the fridge?+
Reconstituted BPC-157 stored in bacteriostatic water lasts 30 days at refrigerator temperature (2–8°C). For storage beyond 30 days, freeze the vial at -20°C where it will last 6+ months. Avoid repeated freeze-thaw cycles — if you need long-term storage, aliquot into smaller vials before freezing.
What does IU mean on an insulin syringe?+
IU (International Units) is the measurement scale on insulin syringes. On a standard 1mL insulin syringe, 100 IU = 1mL = 1,000μL. So 1 IU = 10μL. If you reconstitute 5mg in 1mL (5,000mcg/mL), drawing to the "5 IU" mark gives you 50μL = 250mcg of peptide.
How do I know if my peptide dissolved correctly?+
Correctly reconstituted peptide will be a clear, colorless (or very slightly yellow-tinted) liquid with no visible particles. Cloudiness or particles may indicate contamination, incorrect water type, or a damaged peptide. If the solution looks cloudy or discolored, do not use it.
Can I reconstitute with sterile water instead of BAC water?+
Only if the entire vial will be used in one sitting — regular sterile water contains no preservative (benzyl alcohol) and will allow microbial growth once opened. For any multi-dose protocol (which is nearly every peptide protocol), bacteriostatic water is mandatory. The 0.9% benzyl alcohol in BAC water suppresses bacterial growth for 28 days.
How do I split a large vial across multiple doses safely?+
Once reconstituted, leave the solution in the original vial and draw individual doses with fresh insulin syringes each time. Never pre-draw multiple syringes and store them. Each time you pierce the vial, wipe the stopper with a fresh alcohol swab first. Use within 28–30 days of reconstitution and track the date on your label.
Do reconstituted peptides lose potency over 28 days in the refrigerator?+
There is gradual potency degradation over time, but it is modest within a properly stored vial in BAC water at 2–8°C. Studies suggest most peptides retain 90%+ potency at 28 days under ideal refrigeration conditions. Factors that accelerate degradation: temperature fluctuations, light exposure, and repeated freeze-thaw cycles. For maximum potency, plan cycles so vials are used within 3 weeks of reconstitution.
How do I safely dispose of used syringes?+
Always use a puncture-resistant sharps container. Never place needles in regular trash, recycling, or flush them. Once your sharps container is full (do not overfill — stop at the fill line), seal it. Most pharmacies accept sharps containers for proper disposal. Many local governments have sharps mail-back programs. Some areas have designated sharps drop-off sites. Never recap used needles — this is the leading cause of needlestick injuries.
Get COA-Verified Peptides & Supplies
BPC-157, TB-500, bacteriostatic water, and insulin syringes — everything you need.