SUMMARY OF PROUDCT CHARACTERISTICS

1. NAME OF THE VETERINARY MEDICINAL PRODUCT

Chorulon 1500 IU Powder and Solvent for Solution for Injection

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Powder

Each vial contains:

Active substance:

Chorionic gonadotrophin 1 500 IU Excipients:

Qualitative composition of excipients and other constituents

Mannitol

Disodium phosphate dihydrate

Sodium dihydrogen phosphate dihydrate

Sodium hydroxide (for pH adjustment)

Phosphoric acid (for pH adjustment)

Solvent Each vial contains:

Excipients:

Qualitative composition of excipients and other constituents

Disodium phosphate dihydrate

Sodium dihydrogen phosphate dihydrate

Water for injection

Sodium hydroxide (for pH adjustment)

Phosphoric acid (for pH adjustment)

Reconstituted solution Each ml contains:

Active substance:

Chorionic gonadotrophin 300 IU

Excipients:

Qualitative composition of excipients and other constituents

Mannitol

Disodium phosphate dihydrate

Sodium dihydrogen phosphate dihydrate

Water for injection

Powder: White to off-white.

Solvent: Clear, colourless solution.

3. CLINICAL INFORMATION

3.1 Target species

Cattle, horses and dogs.

3.2 Indications for use for each target species

The veterinary medicinal product can be used in the following fertility problems in domestic animals:

- cases of repeated failure of conception in cows and heifers.

- induction of ovulation in mares and bitches.

- cases of cystic ovaries in cows and heifers.

- anoestrus in mares and bitches.

- delayed ovulation, prolonged pro-oestrus in bitches. - deficiency in libido in male dogs.

3.3 Contraindications None.

3.4 Special warnings

None.

3.5 Special precautions for use

Special precautions for safe use in the target species: Not applicable.

Special precautions to be taken by the person administering the veterinary medicinal product to animals:

Care should be taken to avoid accidental self-injection. In case of accidental self-injection, seek medical advice immediately and show the package leaflet or the label to the physician.

Wash hands after use.

Special precautions for the protection of the environment: Not applicable.

3.6 Adverse events

Cattle, horses, dogs:

Rare (1 to 10 animals / 10 000 animals treated):

Anaphylaxis1

¹ May occur shortly after injection, as with all protein preparations. Adrenalin injection (1:1 000) given intravenously or intramuscularly when symptoms appear is the standard treatment. The administration of corticosteroids may also be indicated.

Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

3.7 Use during pregnancy, lactation or lay

Not applicable.

3.8 Interaction with other medicinal products and other forms of interaction

None known.

3.9 Administration routes and dosage

Intramuscular or intravenous use.

Reconstitute with the solvent provided, ensuring the freeze-dried plug is fully dissolved. Reconstituted solution is colourless.

Administer by intramuscular or intravenous injection, observing the usual aseptic precautions.

Species	Indication	Dosage and administration
Cow, heifer	Repeated failure of conception Cystic ovarian disease (anoestrus, prolonged oestrus, nymphomania) Enhancement of luteal function	1 500 IU – IM or IV at AI or mating. 3 000 IU – IV. 1 500 IU – IM 12 days after insemination or mating.
Mare	Suboestrus (follicles > 2 cm in diameter) Induction of ovulation	1 500 - 3 000 IU – IM or IV, repeat after 2 days if necessary. 1 500 - 3 000 IU – IM or IV 24 hours before AI or mating.
Bitch	Anoestrus Delayed ovulation, prolonged pro-oestrus	500 IU IM or IV at first day of oestrus after pretreatment with PMSG 20 IU/kg SC daily for 10 days. 100 - 800 IU/day IM, repeating treatment until vaginal bleeding disappears. Mate on behavioural oestrus.
Male dog	Deficiency in libido	100 - 500 IU – IM twice weekly for up to 6 weeks, but if this is not possible then 100 - 500 IU IM. 6 - 12 hours before mating may give a temporary effect.

Further information

The product has been used in cases of cryptorchidism in the dog prior to castration (100 – 500 IU intramuscularly twice weekly for up to 6 weeks). Treatment may be effective in some cases provided that the inguinal canal is patent, and that therapy commences early.

The product has intrinsic LH-like activity. Injection of 1 500 IU 12 days after heat in cattle enhances the active life of the corpus luteum by 2 to 3 days, resulting in increased progesterone and suppression of oestradiol production. These changes are consistent with those observed after GnRH use at day 11 – 13 of the cycle which are believed to be responsible for the increased pregnancy rates seen after such use. The mode of action is however different since the product does not rely on first stimulating an endogenous LH peak. This use of the product has not been investigated in the field.

3.10 Symptoms of overdose (and where applicable, emergency procedures and antidotes)

No specific treatment or antidote recommended.

3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance

Not applicable.

3.12 Withdrawal periods

Cattle: Meat and offal – Zero days.

Milk – Zero hours.

Horses: Meat and offal – Zero days.

4. PHARMACOLOGICAL INFORMATION

4.1 ATCvet code: QG03GA01.

4.2 Pharmacodynamics

Chorulon is a freeze-dried presentation of hCG together with solvent for reconstitution. hCG is a gonadotrophin. It is a large glycoprotein composed of two non-covalently associated alpha and beta subunits.

The extensive glycosylation of the CTP tail of the beta subunit of hCG results in its extended half-life which reaches 27 hours in pigs. hCG increases follicle maturation by stimulating androgen production by the cal cells and causes ovulation of the dominant follicle. Owing to its long half-life, it also stimulates formation and function of the corpus luteum.

In the male, hCG stimulates formation of testosterone, thus influencing the development and maintenance of primary and secondary male sexual characteristics.

4.3 Pharmacokinetics

Following IM or IV injection, hCG is rapidly absorbed. Bioavailability following IM injection is high. C_max is reached within 8 hours in all target species. More specifically, peak hCG concentration (0.05 IU/ml) in plasma of cows is achieved 45 minutes after IV injection of a dose of 3 000 IU. The elimination half-life of hCG is about 10 hours in cattle and 27 hours in pigs.

5. PHARMACEUTICAL PARTICULARS

5.1 Major incompatibilities

None known.

5.2 Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 3 years. Shelf life after reconstitution according to directions: 24 hours.

5.3 Special precautions for storage

Storage before reconstitution: Do not store above 25 °C.

Storage after reconstitution:

Protect from light.

Any veterinary medicinal product not used immediately after reconstitution should be stored refrigerated between 2 °C and 8 °C. Reconstituted product remaining 24 hours after preparation should be discarded safely. This veterinary medicinal product does not contain an antimicrobial preservative.

Avoid the introduction of contamination during use.

5.4 Nature and composition of immediate packaging

Powder: Clear, glass Type I vials with halobutyl rubber bung secured with an aluminium collar.

Solvent: Clear, glass Type I vials with halobutyl rubber bung secured with an aluminium collar.

Pack size: Cardboard box with five vials of 1 500 IU powder and five vials of 5 ml solvent.

5.5 Special precautions for the disposal of unused veterinary medicinal product or waste materials derived from the use of such products

Medicines should not be disposed of via wastewater.

Use take-back schemes for the disposal of any unused veterinary medicinal product or waste materials derived thereof in accordance with local requirements and with any national collection systems applicable to the veterinary medicinal product concerned.

6. NAME OF THE MARKETING AUTHORISATION HOLDER

Intervet International B.V.

7. MARKETING AUTHORISATION NUMBER

Vm 06376/4090

8. DATE OF FIRST AUTHORISATION

18 May 1994

9. DATE OF THE LAST REVISION OF THE SUMMARY OF THE PRODUCT CHARACTERISTICS

September 2025

10. CLASSIFICATION OF VETERINARY MEDICINAL PRODUCT

Veterinary medicinal product subject to prescription.

Find more product information by searching for the ‘Product Information Database’ on www.gov.uk.

Gavin Hall Approved: 29 January 2026