HCG Reconstitution Calculator
Calculate HCG injection volumes. Note: HCG is measured in IU (international units). Pre-filled for a 5000 IU vial with 1ml BAC water (5000 IU/ml).
HCG (Human Chorionic Gonadotropin) is a glycoprotein hormone that mimics luteinising hormone (LH), stimulating testosterone production in the testes. In research settings, it is used to maintain testicular function during testosterone therapy and to support fertility. It is measured in International Units (IU), not mcg.
For a 5000 IU HCG vial: add 1ml of bacteriostatic water → concentration is exactly 5000 IU/ml. A commonly referenced 500 IU dose = 0.10ml (10 units) on a 100-unit syringe.
Dose Reference Table
Pre-calculated for a 5mg vial + 1ml BAC water = 5,000 mcg/ml concentration. Using a 100-unit (1ml) insulin syringe.
| Dose | Inject Volume (ml) | Syringe Units |
|---|---|---|
| 100 IU | 0.020 ml | 2 units |
| 250 IU | 0.050 ml | 5 units |
| 500 IU | 0.100 ml | 10 units |
| 1000 IU | 0.200 ml | 20 units |
| 2500 IU | 0.500 ml | 50 units |
| 5000 IU | 1.000 ml | 100 units |
About HCG
HCG (Human Chorionic Gonadotropin) is a glycoprotein hormone produced naturally during pregnancy. It is measured in International Units (IU) rather than mcg/mg. HCG is FDA-approved for treating infertility in women and cryptorchidism (undescended testicles) in boys, and it is used in fertility treatments for both men and women.
HCG is commonly supplied in 5,000 IU or 10,000 IU vials. It must be reconstituted with bacteriostatic water before injection. For a 5,000 IU vial with 1ml BAC water, the concentration is 5,000 IU/ml. A 500 IU dose requires 0.1ml — 10 units on a 100-unit insulin syringe.
In fertility protocols, HCG is used to trigger ovulation in women or to stimulate testosterone production in men. It binds to LH (luteinizing hormone) receptors and mimics the action of LH. For men on testosterone replacement, HCG is sometimes used to maintain testicular function and size.
The reconstitution math is the same as other peptides — concentration = total IU ÷ BAC water volume, injection volume = desired IU ÷ concentration.
How this calculator works
Every result comes from the same three formulas used for any lyophilized peptide: concentration (mcg/ml) = vial mg × 1,000 ÷ BAC water ml; injection volume (ml) = desired dose mcg ÷ concentration; syringe units = injection volume ml × 100 on a U-100 syringe.
For the preset HCG setup on this page: a 5mg vial mixed with 1ml of bacteriostatic water gives a concentration of 5,000 mcg/ml. A 500mcg dose then needs 0.10ml, which is 10 units on a 100-unit insulin syringe.
The full methodology, with worked examples and the assumptions behind each formula, is on the methodology page.
Accuracy & limitations
The arithmetic itself is exact — the same inputs always produce the same output. Real-world accuracy depends on things outside the calculator: actual vial contents can vary slightly from the labeled amount within manufacturing tolerance, the BAC water volume should be measured carefully, and syringe readings are taken at the bottom edge of the plunger. Reconstituted peptides also degrade over time (the common guidance is to use within about 28 days refrigerated), which the math does not model. This tool does arithmetic only — it does not recommend doses, and it is not medical advice.
Last reviewed: September 2026 · Content, formulas and sources checked by Kanika