POM-VPS Prescription Required

Regulin 18 mg Implant

Active ingredient: Melatonin

Form

Implant

Species

Sheep

Manufacturer

Ceva Sante Animale

VMD MA No.

14966/5017

What it's used for

To improve the reproductive performance of pure bred and cross bred lowland sheep which are to be mated early in the season before the usual peak of reprod...

Full indications, dosage and side effects ↓

View official SPC (PDF)

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Clinical information

Regulin 18 mg Implant — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 26 Mar 2026.

To improve the reproductive performance of pure bred and cross bred
lowland sheep which are to be mated early in the season before the
usual peak of reproductive activity.
When used as directed, it stimulates the early onset of natural
reproductive activity giving improved reproductive performance of flocks
mated early in the season. The product is recommended for use in
Suffolk and Suffolk-cross type flocks intended to start lambing between
early December and mid-January and in the Mule and half-bred flocks
starting lambing between late December and mid-February.

Dose:
One implant per ewe by subcutaneous administration at the base of the
ear.
Administration:
Use the implanter to administer one implant near the base of the ear.

Revised: September 2025
AN: 01751/2025
In Suffolk and Suffolk-cross types, the implant should be used from mid-
May to late June for ram introduction in late June and July. In Mule and
half-bred flocks it should be administered from early June to July for ram
introduction from mid-July to late August.
Do not use at times other than those recommended. Do not administer if
sheep are wet or dirty.
Treatment regime:
Day 1 (30 weeks before intended start of lambing).
As the presence of any ram (and also male goats) will interfere with the
ovulatory process, isolate ewes from all males. The ewes should be out
of sight, sound and smell. Separating males into the next field from
females is not adequate.
Day 7:
Implant ewes at the base of the ear. Do not administer if sheep are wet
or dirty. Ewes must remain isolated from male sheep and goats.
Day 42 (35 days after implantation):
The period between implanting and introduction of the males must be
not less than 30 days and no more than 40 days. Introduce rams, but
expect a delay of 14-21 days before mating activity commences.
Vasectomised rams may be used for the first 14 days to ensure a more
compact lambing period. The peak of mating activity will occur 25-35
days after introduction of the rams.

Only use in adult ewes and shearlings
Do not use at times other than those recommended
Use by subcutaneous implantation at the base of the ear only
Not effective on sexually immature animals

Revised: September 2025
AN: 01751/2025

None

Regulin
®
only overcomes the effects of seasonality. If there are any
other adverse influences on reproduction present within a flock, the full
benefit of Regulin treatment may be reduced or even eliminated.
Aspects of implantation related to animal welfare and more intensive
husbandry practices should be discussed with your veterinary surgeon
prior to use.

taken by the person administering the medicinal product to animals
i. Special precautions for use in animals
Avoid damaging implants. Use only sharp undamaged needles.
Needles should be from gamma irradiated packs only. Replace
the needle after each batch of 25 sheep to overcome blunting.
Regulin will not synchronise oestrus.
ii. Special precautions to be taken by the person administering the
medicinal product to animals
Care should be taken to avoid accidental self-injection. In the
case of accidental self-injection, seek medical advice
immediately.

interaction
None known

The product is sterile. Only open each blister section when required. To
maintain sterility, opened product must be discarded at the end of the
working day.
Keep blister trays in outer carton.

Meat: Zero days
Milk: Zero hours
5.

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.