POM-V Prescription Required

Altresyn 4 mg/ml Oral Solution for Pigs

Active ingredient: Altrenogest

Form

Liquid

Species

Pigs

Manufacturer

Ceva Sante Animale

VMD MA No.

14966/3044

What it's used for

For the synchronisation of oestrus in nulliparous mature sows.

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 Altrenogest

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

Altresyn 4 mg/ml Oral Solution for Pigs — SPC Details

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

For the synchronisation of oestrus in nulliparous mature sows.

20 mg altrenogest / animal, i.e. 5 ml per animal once a day.
Treatment duration:
Sexually mature gilts: 18 consecutive days.
Weaned primiparous sows: 3 to 14 consecutive days.
Weaned multiparous sows: 7 consecutive days.
In weaned sows, the treatment should start as closely as possible after weaning.
For 540 and 1080 ml presentations:
The veterinary medicinal product should be administered with the Altresyn doser only.
To prime the doser:
-
-
The doser delivers 5 ml dose for each complete activation of the trigger. For regular
administration hold the vial vertically upside-down. The doser should remain on the bottle
for the whole in-use period, and the lock system should be used during storage between
treatments.
For the 360 ml presentation:
Press and release the metering pump to deliver one 5 ml dose. Do not shake before use
to avoid mixing the solution with the nitrogen included in the pressurised container.
Animals should be dosed individually. Add the veterinary medicinal product as a top
dressing to the surface of the feed immediately before feeding and control the consumption
of the dose. Alternatively, the product can be drenched directly into the animal's mouth by
pressing the dispenser pump with the bottle upside down.
The veterinary medicinal product should be administered at the same time every day.
Ensure the correct dose is administered daily as under-dosing can lead to the formation of
cystic follicles.

Do not administer to animals suffering from uterine infection.
Do not administer to male animals.
See section 3.7.

Pigs:
None known.
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.

None.

Special precautions for safe use in the target species:
Discard any uneaten medicated feed.
For use only in sexually mature gilts that have had at least one oestrous cycle, and in
primiparous and multiparous sows at the time of weaning.
Part consumed feed must be safely disposed of and not given to any other animal.
AN: 00412/2025Page 2 of 6Special precautions to be taken by the person administering the veterinary medicinal
product to animals:
Direct contact with the skin should be avoided. Personal protective clothing (gloves and
overalls) must be worn when handling the veterinary medicinal product. Porous gloves
may let this veterinary medicinal product pass through to the skin. If the veterinary
medicinal product makes contact with the skin underneath the glove, occlusive materials
such as latex or rubber in gloves may enhance transcutaneous absorption of the
veterinary medicinal product.
Accidental spillage on the skin or eyes should be washed off immediately with plenty of
water.
Wash hands after treatment and before meals.
Pregnant women and women of childbearing age should avoid contact with the veterinary
medicinal product or should exercise extreme caution when handling this veterinary
medicinal product.
People suffering from progesterone dependent tumours (known or suspected) or from
thromboembolic disorders should not use the veterinary medicinal product.
Over-exposure effects: Accidental absorption could lead to disruption of the menstrual
cycle, uterine or abdominal cramping, increased or decreased uterine bleeding,
prolongation of pregnancy or headache. Direct contact with the skin should therefore be
avoided.
In case of over-exposure, seek medical advice immediately and show the package leaflet
or the label to the physician.
Special precautions for the protection of the environment:
When spreading manure from treated animals, the minimum distance to surface water as
defined in the national or local regulations has to be strictly respected, because the
manure may contain altrenogest which could cause adverse effects in the aquatic
environment.

None known.
AN: 00412/2025Page 3 of 6

360 ml pressurized container: Protect from sunlight and do not expose to temperatures
exceeding 50 °C. Do not pierce or burn, even after use.
540 and 1080 ml: no special precautions for storage.

Meat and offal: 9 days.
AN: 00412/2025Page 4 of 6
4.

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.