POM-V Prescription Required

Cyclix 250 µg/ml Solution for Injection for Cattle

Active ingredient: Cloprostenol

Form

Injection

Species

Cattle

Manufacturer

Virbac

VMD MA No.

05653/3009

What it's used for

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Full indications, dosage and side effects ↓

View official SPC (PDF)

The prescription itself has a price. See what practices near you charge for a consultation and the written prescription fee.

Paying less for Cloprostenol

1

Ask your vet for a written prescription

They must provide one on request. Under the CMA Order the fee is capped at £21 from 2027.
2

Fill it at a registered online retailer

The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.

Your prescription rights → VMD register of retailers →

Prescription required

Your vet must provide a written prescription on request. You can then purchase from any licensed online retailer.

Clinical information

Cyclix 250 µg/ml Solution for Injection for Cattle — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 27 Mar 2026.

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One dose equals 500 micrograms of cloprostenol per animal, corresponding to 2 ml of the
veterinary medicinal product.
Oestrus induction and synchronisation:
Administer one dose per animal. When no oestrus symptoms are observed, a second
dose can be administered after 11 days.
Treatment of clinical and subclinical endometritis in the presence of a functional corpus
luteum.:
Administer one dose per animal. If necessary, repeat the treatment 10-14 days later.
Treatment of ovarian luteal cysts:
Administer a single dose per animal.
Induction of parturition
Administer a single dose per animal, not earlier than 10 days before the expected date of
calving.
Induction of abortion up to day 150 of gestation:
Administer a single dose per animal, between the 5
th
and the 150
th
day of gestation.
AN: 02638/2024Page 5 of 7

Do not use in pregnant animals in which the induction of abortion or parturition is not
intended.
Do not administer to induce parturition in animals with suspected dystocia due to
mechanical obstruction or abnormal position, presentation and/or posture of the foetus.
Do not use in animals with compromised cardiovascular function, bronchospasm or
gastrointestinal dysmotility.
Do not use in cases of hypersensitivity to the active substance or to any of the excipients.

Cattle (cows):
Rare
(1 to 10 animals / 10,000 animals
treated)
Injection site infection
Very rare
(<1 animal / 10,000 animals
treated, including isolated
reports):
Anaphylaxis
;
Increased respiratory rate
;
Increased heart rate
;
Abdominal pain
, Diarrhoea
3,5
;
Incoordination
;
Lying down
;
Retained placenta
, Metritis
, Dystocia
, Stillbirth
;
Restlessness, Frequent urination
3,5
;
May occur if anaerobic bacteria enter the injection site, especially following intramuscular
injection, and may become generalized. Aggressive antibiotic therapy, particularly covering
clostridial species, should be employed at the first sign of infection. Careful aseptic
techniques should be employed to decrease the possibility of these infections.
Requiring immediate medical attention. Can be life-threatening.
Cloprostenol may cause effects similar to Prostaglandin
muscles.
May be caused by induction of parturition or abortion. As part of induction of parturition,
depending on the date of treatment versus the date of conception, the incidence of
placental retention may be increased.
In case of occurrence, these effects are observed within 15 minutes post-injection and
usually disappear after one hour.
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.
AN: 02638/2024Page 4 of 7

There is a refractory period of four to five days in cattle after ovulation, when females are
insensitive to the luteolytic effect of prostaglandins.
For the termination of gestation in cattle, best results are obtained before day 100 of
gestation. Results are less reliable between day 100 and 150 of gestation.

Special precautions for safe use in the target species:
To reduce the risk of anaerobic infections arising from vasoconstriction at the injection site,
injections into contaminated (wet or dirty) skin areas should be avoided. Thoroughly clean
and disinfect injection sites prior to administration.
Do not administer intravenously.
All animals should receive adequate supervision after treatment.
Induction of parturition or abortion may cause dystocia, stillbirth and/or metritis. The
incidence of retained placenta may be increased depending on the time of treatment
relative to the date of conception.
Injection into adipose tissue can result in incomplete absorption of the veterinary medicinal
product.
Cloprostenol may cause effects related to Prostaglandin activity in the smooth
muscles, such as increased frequency of urination and defecation.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals:
Prostaglandins of the type, such as cloprostenol, may be absorbed through the skin
and may cause bronchospasm or miscarriage. Care should be taken when handling the
veterinary medicinal product to avoid self-injection or skin contact.
Pregnant women, women of childbearing age, asthmatics and persons with other
respiratory tract diseases should avoid contact when handling this veterinary medicinal
product. Personal protective equipment consisting of impervious gloves should be worn
when handling the veterinary medicinal product.
AN: 02638/2024Page 3 of 7
Accidental spillage on the skin should be washed immediately with soap and water. In
case of accidental self-injection or spillage onto the skin seek medical advice immediately,
particularly as shortness of breath may occur, and show the package leaflet or label to the
physician.
This veterinary medicinal product may cause hypersensitive reactions. People with known
hypersensitivity to benzyl alcohol should avoid contact with the veterinary medicinal
product.
Wash hands after use.
Special precautions for the protection of the environment:
Not applicable.

The concomitant use of oxytocin and cloprostenol increases the effects on the uterus.
The concomitant use of progestogens decreases the effect of cloprostenol.
Do not administer with non-steroidal anti-inflammatory drugs (NSAIDs) since they inhibit
endogenous prostaglandin synthesis.

Keep the vial in the outer carton.
Protect from light.

Meat and offal: 1 day.
Milk: Zero hours.

This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.