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Chorulon is presented in vials as a white freeze-dried crystalline plug containing 1500 i.u. Chorionic Gonadotrophin PhEur together with a vial containing 5 ml solvent for reconstitution.

This product does not contain any antimicrobial preservatives.


The active ingredient of Chorulon, human Chorionic Gonadotrophin (hCG), is a complex glycoprotein with luteinising hormone (LH) activity. In the female, hCG can be used to promote maturation of the follicle, ovulation and the formation of the corpus luteum. In the male, Chorulon stimulates the production of testosterone and thus influences the development and maintenance of primary and secondary male sexual characteristics.

Chorulon 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

Dosage and administration

See table. Reconstitute with the solvent provided, ensuring the freeze-dried plug is fully dissolved. Administer by intramuscular or intravenous injection, observing the usual aseptic precautions.

Dosage and administration: Chorulon



Dosage and


Cow, heifer

Repeated failure

of conception

1500 i.u.-i.m. or i.v. at Al or mating

Cystic ovarian

disease (anoestrus,

prolonged oestrus,


3000 i.u.-i.v.

Enhancement of

luteal function

1500 i.u. - i.m. 12 days after insemination or mating.



(follicles>2 cm in


1500–3000 i.u.-i.m. or i.v., repeat after 2 days if necessary.

Induction of


1500–3000 i.u.-i.m. or i.v. 24 hours before Al or mating.



500 i.u.-i.m. or i.v. at first day of oestrus after pretreatment with PMSG 20 i.u./kg s.c. daily, for 10 days.

Delayed ovulation,

prolonged pro-


100–800 i.u./day i.m., repeating treatment until vaginal bleeding disappears. Mate on behavioural oestrus.

Male dog

Deficiency in


100–500 i.u.-i.m. twice weekly for up to 6 weeks, but if this is not possible then 100–500 i.u.-i.m. 6–12 hours before mating may give a temporary effect.

Chorulon has been used in cases of cryptorchidism in the dog prior to castration (100-500 iu i.m. 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. Chorulon has intrinsic LH-like activity. Injection of 1500 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 and are believed to be responsible for the increased pregnancy rates seen after such use. The mode of action is however different, since Chorulon does not rely on first stimulating an endogenous LH peak. This use of Chorulon has not been investigated in the field.

Contra-indications, warnings, etc

In rare cases, as with all protein preparations, anaphylactoid incidents may occur shortly after injection. Adrenalin injection (1:1000) given intravenously or intramuscularly when symptoms appear is the standard treatment. The administration of corticosteroids may also be indicated.

Operator warning

Care should be taken to avoid accidental self-injection.

If accidental self-injection occurs, seek medical advice immediately and show the doctor this package leaflet.

Withdrawal periods:


Meat - zero days

Milk - zero hours


Meat - zero days

For animal treatment only. Keep out of the reach and sight of children.

Pharmaceutical precautions

Before reconstitution: Do not store above 25°C. After reconstitution: Protect from light.

Any 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.

This product does not contain an antimicrobial preservative.

Avoid the introduction of contamination during use.

Dispose of any unused product and empty containers in accordance with guidance from your local waste regulation authority.

Legal category


Packaging Quantities

Packs containing 5 vials supplied together with solvent (each containing 5 ml).

Further information


Marketing authorisation number

Vm 01708/4301.

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