Most research peptides arrive as a powder and nothing else, so the diluent and the storage period are left to the buyer. Chorionic gonadotropin is the exception: every US prescription product ships with its own diluent and a label stating how the two are combined. The catch is that the labels do not agree with each other.
The labelled dose regimens are on our hCG dosage page; the general method and the arithmetic behind any reconstitution are on our reconstitution guide. This page reads the three current hCG labels side by side.
What each product ships with
| Product | Powder | Diluent supplied | After mixing |
|---|---|---|---|
| PREGNYL (Organon) | 10,000 USP units | 10 mL water for injection, 0.56% sodium chloride, 0.9% benzyl alcohol | Refrigerate 2–8 °C, discard after 60 days |
| NOVAREL (Ferring) | 5,000 or 10,000 USP units | 10 mL Bacteriostatic Water for Injection, USP, 0.9% benzyl alcohol | Refrigerate 2–8 °C, use within 30 days |
| Chorionic gonadotropin (Fresenius Kabi) | 10,000 USP units | Bacteriostatic Water for Injection | Refrigerate 2–8 °C, discard after 60 days |
Two points stand out. PREGNYL's solvent is saline with a preservative, not bacteriostatic water — the two are not interchangeable labels for the same liquid. And NOVAREL's in-use period is half the others'. A storage figure quoted without naming the product may be the wrong one. What bacteriostatic water is, and what the benzyl alcohol does, is on our bacteriostatic water page.
PREGNYL's label adds, in capitals, that its benzyl-alcohol solvent is not for use in newborns.
The procedure the labels describe
The NOVAREL label is the most explicit. Before diluting, it instructs the user — the label's wording, not ours — to remove the flip caps from both vials, wipe the tops with an alcohol pad, and not touch them afterwards. The diluent is then added to the powder vial. PREGNYL and Fresenius Kabi both state do not shake and do not freeze.
The concentration table
The NOVAREL label prints the arithmetic:
| Diluent added | 10,000 IU vial | 5,000 IU vial | Label's use |
|---|---|---|---|
| 1 mL | 10,000 IU/mL | 5,000 IU/mL | Entire dose at once |
| 10 mL | 1,000 IU/mL | 500 IU/mL | Multiple doses, refrigerated between |
The other two labels list the 10 mL solvent vial for multiple-dose use. Strength is stated in USP units, a potency measure set against a reference standard, not a weight — so hCG figures do not convert to milligrams the way most research peptides do.
The arithmetic per syringe mark
Many people measure reconstituted hCG with a U-100 insulin syringe, whose marks are volume: one "unit" mark is 0.01 mL. The IU in each mark therefore depends entirely on the concentration:
| Concentration | IU per 0.01 mL mark | IU in 0.1 mL (10 marks) |
|---|---|---|
| 10,000 IU in 10 mL (1,000 IU/mL) | 10 | 100 |
| 5,000 IU in 10 mL (500 IU/mL) | 5 | 50 |
| 10,000 IU in 5 mL (2,000 IU/mL) | 20 | 200 |
| 10,000 IU in 1 mL (10,000 IU/mL) | 100 | 1,000 |
The last row is the label's single-dose strength. At that concentration a one-mark misreading is 100 IU. Syringe types and their markings are compared on our syringes for peptides page.
Route: the labels say intramuscular
All three urinary hCG labels state intramuscular use only. Recombinant hCG is different: Ovidrel (choriogonadotropin alfa) comes as a liquid prefilled syringe, 250 micrograms in 0.5 mL, given under the skin and never reconstituted. Clinic and online protocols often describe subcutaneous injection of reconstituted urinary hCG; the urinary labels do not address it, and that is a gap in the label record, not a finding about safety. The harms each label lists are counted on our hCG side effects page.
What the labels do not cover
- Any diluent other than the one supplied. The 30- and 60-day periods were set for those combinations.
- Products without a label — "hCG" sold as a research powder, with no diluent and no stated potency. A potency claim in USP units needs a bioassay to support it, which is more than a purity test shows; see what a certificate of analysis measures.
- Pre-filled syringes made up from a vial and stored. None of the labels gives a period for that.
How hCG compares with the hypothalamic peptide often sold beside it is on our gonadorelin vs hCG page. What hCG is and does is on Peptide Lexicon's hCG entry.
Sources and dates
- PREGNYL (chorionic gonadotropin for injection) prescribing information, Organon LLC, BLA 017692, via openFDA, effective 2025-12-02: description, dosage and administration, how supplied, storage (read 2026-10-04).
- NOVAREL prescribing information, Ferring Pharmaceuticals, BLA 017016, via openFDA, effective 2025-08-27: Table 1 and reconstitution note, how supplied, storage (read 2026-10-04).
- Chorionic Gonadotropin for Injection, Fresenius Kabi USA, BLA 017067, via openFDA, revised February 2025: description, how supplied, storage (read 2026-10-04).
- Ovidrel (choriogonadotropin alfa injection) prescribing information, BLA 021149, via openFDA, effective 2023-12-26: how supplied (read 2026-10-04).
Corrections go to the contact page.