How do you reconstitute HCG?

Add 2 mL of bacteriostatic water to a 5000 IU HCG vial to get 2500 IU/mL. Inject slowly along the inside vial wall, swirl gently, and refrigerate. For a 250 IU dose, draw to the 10-unit line on a 100-unit insulin syringe.

How much bacteriostatic water do you add to HCG?

For a 5000 IU vial: 2 mL is standard, giving 2500 IU/mL. For a 10000 IU vial: 5 mL is common, giving 2000 IU/mL. Using more water lowers concentration and makes small doses easier to measure accurately on a syringe.

How long does reconstituted HCG last?

Reconstituted HCG stored at 2-8C in bacteriostatic water is stable for approximately 30 days. Lyophilized HCG powder can be stored at room temperature for up to 24 months. Never freeze the reconstituted solution.

Why should you never shake HCG?

HCG is a large glycoprotein hormone (molecular weight ~36,700 Da) with a complex tertiary structure. Shaking creates mechanical stress and foaming that can denature the protein and destroy biological activity. Always swirl gently or let sit until dissolved.

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How to reconstitute HCG

Human Chorionic Gonadotropin (HCG) is supplied as a lyophilized (freeze-dried) powder and must be reconstituted with bacteriostatic water before use. Unlike small peptides, HCG is a large glycoprotein hormone with a molecular weight of approximately 36,700 Da, making it more sensitive to heat and mechanical stress during mixing. The process is straightforward when done correctly.

TL;DR - Add 2 mL of bacteriostatic water to a 5000 IU vial for 2500 IU/mL. For a 250 IU dose: draw to the 10-unit line on a 100-unit insulin syringe. Swirl gently, never shake. Refrigerate and use within 30 days.

Step-by-step reconstitution

Wipe the rubber stopper of both the HCG vial and the bacteriostatic water vial with fresh alcohol swabs. Let dry for 10 seconds.

Draw your chosen volume of bacteriostatic water into a syringe. Standard amounts: 2 mL for a 5000 IU vial, or 5 mL for a 10000 IU vial. More water means lower concentration and easier measurement of small doses.

Insert the needle into the HCG vial and point it toward the inside glass wall. Push the plunger slowly so the water trickles down the wall and wets the powder gently from underneath. Do not aim directly at the powder cake.

Remove the needle and gently roll the vial between your palms in slow circles for 20-30 seconds. HCG typically dissolves to a clear or very slightly yellow solution. If any cloudiness remains, let the vial sit in the refrigerator for 10 minutes before checking again.

Label the vial with today's date and the concentration. Refrigerate immediately at 2-8C.

Never shake HCG. HCG is a complex glycoprotein. Shaking creates foaming and mechanical stress that denatures the protein structure and destroys biological activity. Swirl only.

Concentration table: 5000 IU vial

Syringe units shown are for a 250 IU dose on a standard 100-unit (1 mL) insulin syringe.

BAC Water Added	Concentration	250 IU dose =
1 mL	5000 IU/mL	5 units
2 mL	2500 IU/mL	10 units
5 mL	1000 IU/mL	25 units

Recommendation: 2 mL is the most practical ratio for a 5000 IU vial. It gives manageable syringe volumes for the common 125-500 IU dose range without being so dilute that you need large syringe volumes.

Concentration table: 10000 IU vial

Syringe units shown are for a 250 IU dose on a standard 100-unit (1 mL) insulin syringe.

BAC Water Added	Concentration	250 IU dose =
2 mL	5000 IU/mL	5 units
5 mL	2000 IU/mL	12.5 units
10 mL	1000 IU/mL	25 units

Storage after reconstitution

Reconstituted HCG in bacteriostatic water is stable for approximately 30 days at 2-8C. The benzyl alcohol in BAC water inhibits bacterial contamination, but peptide degradation continues at refrigerator temperatures over time. Use within 30 days for best potency.

Lyophilized HCG powder is stable at room temperature for up to 24 months from manufacture when kept dry and away from direct light. Refrigerating the powder extends stability further.

Do not freeze reconstituted HCG. Ice crystal formation physically ruptures the protein structure. The lyophilized powder can be frozen, but once dissolved in BAC water it must stay in the 2-8C range only.

Common mistakes

The three most frequent errors when reconstituting HCG:

Injecting water directly onto the powder. This causes foaming and uneven dissolution. Always aim at the glass wall.

Using sterile water instead of bacteriostatic water. Sterile water has no preservative, meaning the vial must be used in a single session after opening. BAC water allows multi-draw use for up to 30 days.

Confusing vial sizes. A 5000 IU vial and a 10000 IU vial require different water volumes to achieve the same concentration. Always confirm your vial IU before calculating your dose. Use the ASCEND HCG calculator to avoid errors.

Full Peptide Reconstitution Guide →

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Research References

Cole LA - Biological functions of hCG and hCG-related molecules
Reprod Biol Endocrinol 2010 · PMID 17636450

Wang W. - Instability, stabilization of liquid protein pharmaceuticals
Int J Pharm 1999 · PMID 10502313 · Protein stability basis

ASCEND is a mathematical reference tool for research purposes only. Not for medical use.
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