You've received your first peptide vial, a small bottle of freeze-dried powder that looks nothing like an injectable solution. You need to reconstitute it with bacteriostatic water, but you're worried about making a mistake that wastes expensive product. Here's what you need to know to get it right the first time.
Reconstitution means mixing lyophilized (freeze-dried) peptide powder with sterile liquid to create an injectable solution. Add bacteriostatic water slowly down the vial wall, swirl gently until dissolved, and refrigerate immediately.
Simple doesn't mean foolproof. Incorrectly reconstituted peptides lose 20-60% of their potency within 48 hours from common mistakes: shaking instead of swirling, wrong water type, or room temperature storage.
When done correctly, reconstitution preserves 95% or more of your peptide's potency for 28-30 days when refrigerated. The key is understanding the critical differences between bacteriostatic and sterile water, following the exact 10-step protocol, and avoiding the five mistakes that cause 70% of reconstitution failures.
Quick Reference:
- Use bacteriostatic water (0.9% benzyl alcohol preservative)
- Standard ratio: 2ml water per 5mg peptide vial
- Add water slowly down vial wall (never spray directly on powder)
- Swirl gently in circles (never shake)
- Refrigerate immediately at 36-46°F
- Stable 28-30 days when properly stored
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What is Peptide Reconstitution?
Reconstitution = mixing freeze-dried peptide powder (lyophilized) with sterile liquid to create an injectable solution.
Lyophilized (freeze-dried) peptides remain stable at room temperature for 12-24 months. Once reconstituted with water, stability drops to 28-30 days even when refrigerated.
Common peptides requiring reconstitution:
- BPC-157 (injury healing)
- TB-500 (systemic repair)
- Ipamorelin (growth hormone)
- GHK-Cu (collagen synthesis)
- Melanotan II (tanning)
- PT-141 (libido)
Bacteriostatic vs Sterile Water
Bacteriostatic Water (RECOMMENDED):
- Sterile water + 0.9% benzyl alcohol (preservative)
- Benzyl alcohol inhibits bacterial growth for 28-30 days, allowing multiple-dose use from same vial
- Best for multi-dose vials used over days/weeks
- Where to buy: Amazon "Bacteriostatic Water 30ml" ($8-12), peptide suppliers, compounding pharmacies
- Shelf life: Unopened = 3 years. Opened = 28 days
Sterile Water (SINGLE-DOSE ONLY):
- Pure H₂O with no preservatives
- Bacteria-free when sealed, but bacteria grows within 24-48 hours after opening
- Only use if injecting entire vial in one shot
Verdict: Use bacteriostatic water unless you have a specific reason not to. It's the industry standard.
Step-by-Step Reconstitution Protocol
Supplies needed:
- Lyophilized peptide vial
- Bacteriostatic water (10-30ml)
- Insulin syringes (1ml, 29-31 gauge)
- Alcohol swabs (70% isopropyl)
- Sharps container
Total cost: $35-50 for full kit (supplies last 3-6 months).
10-Step Protocol
Step 1: Prepare workspace (clean countertop, wash hands 30 seconds, lay out supplies).
Step 2: Determine water amount (Standard: 2ml water for 5mg vials, 4ml for 10mg vials).
Step 3: Sterilize vial tops (wipe each rubber stopper with alcohol swab, let air dry 10-15 seconds).
Step 4: Draw bacteriostatic water (pull plunger to desired amount, insert needle into water vial, push air in, flip vial, draw water).
Step 5: Add water to peptide vial CRITICAL: Hold vial at 45° angle, point needle at WALL of vial (NOT onto powder), slowly push plunger over 10-15 seconds, let water run DOWN the inside wall. NEVER spray directly onto powder.
Step 6: Dissolve gently (swirl in circular motion 30-60 seconds, NEVER SHAKE, let sit 2-5 minutes if not fully dissolved).
Step 7: Label vial (concentration e.g. "2.5mg/ml", date reconstituted, expiration +28 days).
Step 8: Store immediately (refrigerate at 36-46°F, back of fridge, upright position).
Step 9: Calculate your dose (see formula below or use our calculator).
Step 10: Draw and inject (wipe top, draw dose, check for bubbles, inject, return to fridge).
Dose Calculation Formula
Step 1: Concentration (mg/ml) = Total peptide (mg) ÷ Total water (ml)
Step 2: Injection volume (ml) = Desired dose (mg) ÷ Concentration (mg/ml)
Example: 5mg BPC-157 + 2ml water = 2.5mg/ml concentration. For 250mcg (0.25mg) dose: 0.25mg ÷ 2.5mg/ml = 0.1ml to inject (10 units on insulin syringe).
Skip the math! Use our Peptide Reconstitution Calculator for instant calculations.
For BPC-157 specifically, try our BPC-157 Dosage Calculator.
5 Critical Mistakes to Avoid
Mistake #1: Shaking the vial: Shaking creates foam, denatures peptide bonds, reduces potency by 30-50%. Correct: Gentle circular swirl.
Mistake #2: Spraying water directly on powder: High-pressure water impact breaks peptide structure. Correct: Aim needle at vial wall, let water slide down gently.
Mistake #3: Using tap or distilled water: Tap water: bacteria, minerals, chlorine. Distilled water: no preservative, bacteria grows within 24h. Correct: Bacteriostatic water.
Mistake #4: Not refrigerating immediately: Room temperature degrades peptides by 10-20% per day. After 72h at room temp, potency <50%. Correct: Refrigerate immediately at 36-46°F.
Mistake #5: Reusing needles: Needles dull after one use (more pain), bacterial contamination risk increases 300%, false economy (syringes cost $0.12 each). Correct: Fresh syringe every injection.
Storage and Shelf Life
Lyophilized powder (unreconstituted):
- Room temp (68-77°F) = stable 12-24 months
- Refrigerated (36-46°F) = 24-36 months
- Frozen (-4 to -13°F) = 36-48 months (only for sealed powder, never freeze reconstituted)
Reconstituted peptides (bacteriostatic water):
- Refrigerated (36-46°F):
- BPC-157, TB-500, Ipamorelin = 28-30 days
- GHK-Cu = 21-28 days (copper oxidizes faster)
- Melanotan II = 30-40 days
Signs of degradation (discard immediately):
- Cloudiness or particles floating
- Color change (yellow/brown)
- Foul smell
- No results after 2-3 weeks at proper dose
Frequently Asked Questions
Can I use sterile water instead of bacteriostatic water?
Yes, BUT only if you use the entire vial within 24 hours. Sterile water has no preservative, so bacteria grows rapidly. For multi-dose use over days/weeks (standard protocols), you MUST use bacteriostatic water.
Exception: If allergic to benzyl alcohol (<1%), use sterile water and inject full vial each time.
How long do reconstituted peptides last in the fridge?
28-30 days for most peptides when reconstituted with bacteriostatic water and stored at 36-46°F. Mark your vial with expiration date (reconstitution date + 28 days). After 30 days, benzyl alcohol preservative degrades and potency drops 15-25%.
What if my peptide doesn't fully dissolve?
Let it sit 5-10 minutes. Some peptides dissolve slowly. Still cloudy?
Try gently swirling again (don't shake). If particles remain after 20 minutes, the peptide is likely degraded or contaminated; discard and contact supplier.
Can I reconstitute the entire vial at once?
Yes, reconstitute entire vial at once (not batches). Lyophilized powder is stable; reconstituted liquid is not. Opening the vial multiple times introduces contamination risk and wastes product.
One-time reconstitution with bacteriostatic water gives you 28-30 days of stable use.
How many doses are in my vial?
Formula: Total peptide (mg) ÷ Dose per injection (mg) = Number of doses. Example: 5mg BPC-157 vial at 250mcg (0.25mg) per dose = 5mg ÷ 0.25mg = 20 doses. Use our calculator for instant results.
The Bottom Line
Reconstituting peptides correctly is simple when you follow the proven protocol: use bacteriostatic water, add it slowly down the vial wall, swirl gently (never shake), and refrigerate immediately. These 4 steps preserve 95%+ potency for 28-30 days.
Most common beginner mistake: Shaking instead of swirling (40% potency loss). Just this one fix will double your results.
Ready to reconstitute your first peptide?
- Take our Peptide Quiz: Get personalized recommendations in 2 minutes
- Free Reconstitution Calculator: Get exact dosing instantly
- How to Inject Peptides: Step-by-step injection technique
- BPC-157 Dosage Calculator: Complete BPC-157 protocol
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