B7-33 Reconstitution Calculator
Enter the amount you want to measure. The vial buttons will highlight which vial strengths create cleaner syringe-unit measurements.
What amount do you need?
Type the target amount, then choose mg or mcg. Example: 2mg or 500mcg.
Syringe size:
Possible vial strengths:
Best Match
Good Match
Usable
Harder to Measure
Example B7-33 Titration Schedule
| Protocol Item | Guidance |
|---|---|
| Dose | 200–800 mcg per dose |
| Cycling | Daily, for 30-day cycles (or shorter), with a 30-day minimum cycle break between |
Possible vial strengths:
What Is It?
B7-33
Single-chain relaxin analogue.
Bacteriostatic Water
Sterile water containing a bacteriostatic preservative, commonly used when preparing multi-use research vials.
How To Mix B7-33
1
CleanUse alcohol swabs to clean the tops of both vials.
2
Draw BAC WaterDraw the selected amount of bacteriostatic water.
3
Inject SlowlyAdd the liquid slowly down the side of the vial.
4
Swirl GentlyDo not shake. Swirl gently until dissolved.
5
Store ProperlyStore as directed and protect from heat and light.
Best Practices & Common Mistakes
Best Practices
- Use sterile technique.
- Protect from light and heat.
- Store refrigerated when appropriate.
- Use clean syringe-unit math before measuring.
Common Mistakes
- Confusing milligrams with milliliters.
- Choosing an option with awkward decimal units.
- Using too little liquid for very small measurements.
- Shaking the vial aggressively.
B7-33 Storage & Handling
Lyophilized Powder: −20°C (−4°F) for long-term storage (up to 24 months). Refrigeration 2–8°C (36–46°F) for short-term use (up to ~3 months). Original sealed vial in the freezer is safest.
Reconstituted Solution: 2–8°C (36–46°F), use within ~7–14 days. Keep sealed, avoid light, and do not repeat freeze-thaw cycles.
Reconstituted Solution: 2–8°C (36–46°F), use within ~7–14 days. Keep sealed, avoid light, and do not repeat freeze-thaw cycles.
Frequently Asked Questions
Divide mcg by 1000 to get mg. For example, 50 mcg = 0.05 mg; 100 mcg = 0.10 mg; 200 mcg = 0.20 mg. Enter this decimal value in the “Desired dose” field. Be very careful not to enter the mcg number as mg – 50 mg instead of 0.05 mg would be 1000× too high and likely show “Poor” or impossible volumes.
With a 5 mg vial and 1 mL BAC → 5 mg/mL → 0.05 mg = 0.01 mL = 1 unit (below the calculator’s 4‑unit “Poor” threshold). Any volume below 4 units is marked “Poor” because it is extremely difficult to measure accurately. To get a usable measurement, either increase your dose (if appropriate) or use a larger BAC volume and a smaller vial. Example: 5 mg vial + 5 mL BAC → 1 mg/mL → 0.05 mg = 0.05 mL = 5 units – now above 4 units, possibly “Usable” or “Good” if it lands on a whole unit. The calculator’s color coding will show the best available option.
Use the largest BAC volume possible (5 mL) and the smallest vial strength (5 mg) to create a low concentration. For a 100 mcg (0.1 mg) dose:
5 mg vial + 5 mL BAC → 1 mg/mL → 0.1 mg = 0.1 mL = 10 units on a 100‑unit syringe → ✅ “Best” (multiple of 5).
Also, choose a larger syringe (100 units rather than 30 or 50) because it gives finer tick marks and more room. Avoid 30‑unit syringes for such small volumes. The calculator’s green “Best” highlight will guide you.
5 mg vial + 5 mL BAC → 1 mg/mL → 0.1 mg = 0.1 mL = 10 units on a 100‑unit syringe → ✅ “Best” (multiple of 5).
Also, choose a larger syringe (100 units rather than 30 or 50) because it gives finer tick marks and more room. Avoid 30‑unit syringes for such small volumes. The calculator’s green “Best” highlight will guide you.
Yes, you do not need to remix the vial. Once you reconstitute a vial with a chosen BAC volume, simply change the “Desired dose” field to your new mg value. Example: 5 mg vial + 5 mL BAC → 1 mg/mL.
50 mcg (0.05 mg) → 0.05 mL = 5 units
100 mcg (0.10 mg) → 0.10 mL = 10 units
200 mcg (0.20 mg) → 0.20 mL = 20 units
All are multiples of 5, so accuracy remains high. The “Doses per vial” display will update automatically, showing fewer doses at higher amounts.
50 mcg (0.05 mg) → 0.05 mL = 5 units
100 mcg (0.10 mg) → 0.10 mL = 10 units
200 mcg (0.20 mg) → 0.20 mL = 20 units
All are multiples of 5, so accuracy remains high. The “Doses per vial” display will update automatically, showing fewer doses at higher amounts.
For low doses (≤0.2 mg), 5 mL is almost always the best because it gives the lowest concentration and therefore the largest draw volume in units, which minimizes measurement error. However, if your vial is larger than 5 mg (e.g., 10 mg) and you use 5 mL BAC, concentration = 2 mg/mL → 0.1 mg = 0.05 mL = 5 units – still acceptable. Avoid using 1 mL BAC with small doses, as that creates very high concentration and tiny volumes (e.g., 10 mg in 1 mL → 0.1 mg = 1 unit → “Poor”). The calculator will highlight 5 mL options in green or orange if they yield clean unit measurements.
Practical takeaway: If your real goal is weight or metabolic health, the most useful next step is discussing approved treatment options with a clinician rather than relying on an unapproved compound.
Important: This tool is for informational and research-reference purposes only. Not intended for human or veterinary use.