HCG Reconstitution Calculator
Convert any HCG vial into exact insulin syringe units. Enter your vial IU, the bacteriostatic water you added, and your target dose.
Draw syringe to
10 units
(0.10 mL)
2,500 IU/mL
Concentration
0.1 mL
Per Dose
20
Doses / Vial
For educational and research purposes only. This calculator provides estimates based on standard formulas.
Always verify calculations with your healthcare provider before use. We assume no liability for dosing errors, adverse events, or outcomes resulting from use of this tool.
How to reconstitute HCG
HCG ships as a freeze-dried powder paired with a small ampule of diluent. For multi-dose use, most TRT and fertility protocols substitute the supplied diluent with bacteriostatic water, which contains 0.9 percent benzyl alcohol as a preservative. That preservative is what lets a single reconstituted vial last roughly 30 days under refrigeration.
The reconstitution itself is straightforward. Swab the vial stopper with alcohol, draw your chosen volume of BAC water (1 to 3 mL is typical), and inject it slowly down the inside wall of the HCG vial. Do not aim the stream at the powder. Once the water is in, gently swirl the vial. Do not shake. HCG is a protein and aggressive agitation can denature it.
The amount of BAC water you add determines your concentration and how easy each dose is to draw. For a 5,000 IU vial reconstituted with 2 mL, your concentration is 2,500 IU per mL, which gives clean unit math: 250 IU equals 10 units on a 100-unit insulin syringe, and 500 IU equals 20 units. Larger volumes make each dose easier to measure but consume the vial faster.
Standard injection technique is subcutaneous in the lower abdomen or outer thigh using a 29 to 31 gauge, 1/2 inch needle. Rotate sites across each injection day to avoid scar tissue buildup. Always store reconstituted HCG in the refrigerator between 36 to 46 F, and discard if the solution becomes cloudy.
Worked example: 5,000 IU vial
Take a 5,000 IU vial and add 2 mL of bacteriostatic water. Your concentration is 5,000 divided by 2, or 2,500 IU per mL. On a 100-unit insulin syringe (where 100 units equals 1 mL), every unit holds 25 IU.
- 250 IU dose: draw 10 units (0.10 mL). Gives 20 doses per vial.
- 500 IU dose: draw 20 units (0.20 mL). Gives 10 doses per vial.
- 1,000 IU dose: draw 40 units (0.40 mL). Gives 5 doses per vial.
Adjust the BAC water volume if you prefer different unit math. Many people on 250 IU twice-weekly TRT-adjunct protocols use 2 mL because the 10-unit draw is easy to read on the syringe markings.
Frequently asked questions
How do I reconstitute 5,000 IU HCG?
Add 2 mL of bacteriostatic water to the 5,000 IU vial. That gives you a concentration of 2,500 IU per mL. On a standard 100-unit insulin syringe, 1 unit equals 25 IU. For a 250 IU dose, draw 10 units. For a 500 IU dose, draw 20 units.
How long does reconstituted HCG last?
Refrigerated between 36 to 46 F (2 to 8 C), reconstituted HCG remains potent for approximately 30 days when mixed with bacteriostatic water. Discard immediately if the solution turns cloudy or develops particulate.
What gauge needle should I use for HCG injections?
A 29 to 31 gauge, 1/2 inch needle is standard for subcutaneous HCG injection. Rotate injection sites between the lower abdomen and outer thigh to avoid scar tissue buildup.
Can I mix HCG with other peptides in the same vial?
No. HCG has its own reconstitution profile and refrigeration requirement. Mixing it with other peptides risks degradation and contamination. Store HCG separately and inject other compounds in their own syringes.
See also: Daily TRT insulin syringe dose guide and HCG dose calculator.
How to use this calculator
Enter vial size
5,000 IU and 10,000 IU are the most common HCG vial sizes
Enter BAC water volume
Typically 1 to 3 mL depending on how many doses you want per vial
Enter target dose
Common TRT-adjunct doses are 250 IU and 500 IU two to three times weekly
Read the syringe units
The calculator returns exact units on a 100-unit insulin syringe
Track your HCG protocol, not just the math
Regimen logs each HCG injection alongside your TRT compound, with reminders and PK curve visualization.
- Built-in dose calculators
- Smart injection reminders
- Track progress over time
- Private, secure health data
