STORAGE AND HANDLING PRECAUTIONS Store at or below room temperature, 25°C (77°F). Keep out of reach of children. Once reconstituted, CHORULON ® should be used immediately. Unused solution should be disposed of properly and not stored for future use.
(chorionic gonadotropin for injection)
Approved by FDA under NADA # 140-927
FOR ANIMAL USE ONLY
CAUTION
Federal law restricts this drug to use by or on the order of a licensed veterinarian.
DESCRIPTION
CHORULON® is a freeze-dried preparation of chorionic gonadotropin (human Chorionic Gonadotropin or hCG) for intramuscular administration after reconstitution. When reconstituted with the accompanying sterile diluent, each 10 mL vial contains 10,000 International Units chorionic gonadotropin (equivalent to 10,000 USP Units chorionic gonadotropin) and 10 mg mannitol, with mono- and disodium phosphate to adjust the pH of the solution.
ACTION
Chorionic gonadotropin has luteinizing hormone-like activity with little or no follicle stimulating or estrogenic activity. Product does not conform to the USP monograph for estrogenic activity. Demonstration of the lack of estrogenic activity is performed at the drug substance level.
INDICATIONS
COWS: CHORULON® is indicated for intramuscular use in cows for the treatment of nymphomania (frequent or constant heat) due to cystic ovaries.
FINFISH: CHORULON® is indicated for use as an aid in improving spawning function in male and female brood finfish.
DOSAGE AND ADMINISTRATION
To reconstitute, transfer the contents of one vial of sterile diluent into one vial of freeze-dried powder. The resulting 10 mL of CHORULON® contains 10,000 International Units chorionic gonadotropin.
COWS: The contents of one vial (10 mL) of reconstituted CHORULON® should be administered as a single deep intramuscular injection. Dosage may be repeated in 14 days if the animal's behavior or rectal examination of the ovaries indicates the necessity for retreatment.
FINFISH: CHORULON® should be administered via intramuscular injection just ventral to the dorsal fin for one (1) to three (3) injections. Any single injection should be administered, depending on the fish species, at a dose of 50 to 510 International Units/lb body weight (bw) for males and 67 to 1816 International Units/lb bw for females. Depending on body weight and dose administered, it may be necessary to divide the dose among two or more injection sites to avoid injecting a large volume at a single site.
Summaries of doses tested in representative fish species are contained within the following tables. The dose of CHORULON® to be used in other species of finfish may differ from those species listed in the tables, but should fall within the suggested range of 50 to 510 International Units/lb bw for males and 67 to 1816 International Units/lb bw for females.
| Nomenclature Common Name, Genus & Species, Family | Tested Dose(s) (International Units/lb bw/injection) | Number of Injections | Injections Interval (h) | |
|---|---|---|---|---|
| Males | Females | |||
| Footnotes: | ||||
| yellow perch, Perca flavescens, Percidae | nt1 | 67-300 | 1 | - |
| striped bass, Morone saxitilis, Percichthyidae | 50-500 | 75-252 | 1 | - |
| white bass, Morone chrysops, Percichthyidae | 65-510 | 91-750 | 1 | - |
| razorback sucker, Xyrauchen texanus, Catostomidae | nt* | 100 | 3 | 24 |
| walleye, Stizostedion vitreum, Percidae | 75-400 | 145-830 | 1-3 | 72 |
| red snapper, Lutjanus campechanus, Lutjanidae | 250 | 500 | 1 | - |
| sauger, Stizostedion canadense, Percidae | 500 | 500-1000 | 1 | - |
| Chinese catfish, Clarius fuscus, Clariidae | nt* | 1816 | 1 | - |
* nt = not tested
| Nomenclature Common Name, Genus & Species, Family | Tested Dose(s) (International Units/lb bw/injection) | Number of Injections | Injections Interval (h) | |
|---|---|---|---|---|
| Males | Females | |||
| white bass, Morone chrysops, Percichthyidae | 750 | 1500 | 1 | - |
| walleye, Stizostedion vitreum, Percidae | 750 | 1500 | 1 | - |
| grass carp, Ctenopharyngodon idella, Cyprinidae | 2500 | 5000 | 1 | - |
| channel catfish, Ictalurus punctatus, Ictaluridae | 2500 | 5000 | 1 | - |
ADVERSE REACTIONS
Chorionic gonadotropin is a protein. In the unlikely event of an anaphylactic reaction, epinephrine should be administered. The administration of an antihistamine may also be indicated.
RESIDUE WARNINGS
No withdrawal period is required for cows or brood finfish treated according to label directions. The total dose administered (all injections combined) should not exceed 25,000 International Units (25 mL) per fish in fish intended for human consumption.
STORAGE AND HANDLING PRECAUTIONS
Store at or below room temperature, 25°C (77°F). Keep out of reach of children. Once reconstituted, CHORULON® should be used immediately. Unused solution should be disposed of properly and not stored for future use.
HOW SUPPLIED
CHORULON® is supplied in cartons containing five vials of freeze-dried powder and five 10 mL vials of sterile diluent.
Distributed by Intervet Inc. (d/b/a Merck Animal Health), Rahway, NJ 07065.
Copyright © 2026 Merck & Co., Inc., Rahway, NJ, USA and its affiliates.
All rights reserved.
Rev. 08/2026
255875 R1 INU 240
07
MERCK
Animal Health
5 vials with diluent
chorulon®
(chorionic gonadotropin for injection)
MERCK
Animal Health
| Ingredient | Type | UNII | SPL version | Uploaded |
|---|---|---|---|---|
| Gonadotrophin, Chorionic | ACTIVE INGREDIENT | 20ED16GHEB | 1 | |
| Gonadotrophin, Chorionic | ACTIVE MOIETY | 20ED16GHEB | 1 | |
| Water | INACTIVE INGREDIENT | 059QF0KO0R | 1 |
Every source-derived product name is available through these pages.
| Product NDC | Package NDC |
|---|---|
| 57926-475 | 57926-475-62 |
Every source-derived ingredient row is available through these pages.
| Name | UNII | Kind |
|---|---|---|
| CHORIONIC GONADOTROPIN | 20ED16GHEB | ACTIB |
| WATER | 059QF0KO0R | IACT |
| Version | Effective date | Source | Hydrated |
|---|---|---|---|
| 5 | 2026-02-19 | full-release | 2026-06-01 02:46:26 |
OpenFDA label data provides additional search and identifier links. DailyMed’s Structured Product Label is the canonical label on FDA.report. Matching records are deduplicated before they are shown below.
| Brand | Generic | Manufacturer | SPL set ID | Effective date | Available safety fields | Join |
|---|---|---|---|---|---|---|
| Chorionic Gonadotropin | CHORIONIC GONADOTROPIN | Fresenius Kabi USA, LLC | f93b2baa-03ac-4650-b35a-20b818d712d6 | 2025-04-11 | Warnings, Adverse reactions | CHORIONIC GONADOTROPIN |
| Chorionic Gonadotropin | CHORIONIC GONADOTROPIN | NuCare Pharmaceuticals,Inc. | 312ee87a-c6c3-6111-e063-6394a90ad8d7 | 2025-03-25 | Warnings, Adverse reactions | CHORIONIC GONADOTROPIN |
Adverse event summaries are temporarily unavailable. Other product information remains available.